22.8.17

Viaggi in bicicletta

http://www.touringclub.it/notizie/bicicletta?utm_source=NLbicicletta1708NS&utm_medium=email&utm_campaign=Bicicletta&utm_content=deltadelP%C3%B2&RCookie=1

Djursland, sorprese dal cuore della Danimarca - Repubblica.it

Djursland, sorprese dal cuore della Danimarca - Repubblica.it

Djursland, sorprese dal cuore della Danimarca

Djursland, sorprese dal cuore della Danimarca
Dov'é il centro della Danimarca? A Copenhagen, capitale del Regno? Acqua. Ad Aarhus, capitale europea della cultura (e seconda città del paese? Fuochino. Si trova a tre quarti d'ora da lì, sulla collina Agri Bavnehøj. La geografia inganna il viaggiatore distratto, la geometria confonde il lettore pigro: quel puntino nello Jutland sembra troppo ad ovest per segnare il cuore geografico. È invece così e per parecchio tempo da lassù si sono misurate le distanze riportate nelle antiche carte reali. È uno sbalzo ondulato che supera di qualche decina di metri i cento di altitudine – non poco per una nazione che ha chiama Himmelbjerget ("Montagna del Cielo") il suo punto più alto (sfiora i centocinquanta) – e si trova nel parco Mols Bjerge. È l'atout più prezioso del Djursland, coi suoi duecentocinquanta chilometri di costa del Kattegat e le decine di variazioni sul tema "entroterra danese di charme": tutte da cartolina, sono la quintessenza dell'idillio sottovoce a portata di mano.

Molte delle iniziative fuori-città del calendario di Aarhus 2017 si tengono da queste parti, nel "naso della Danimarca". E qui c'è l'aeroporto che serve la comunità, il Tirstrup Lufthavn. Niente scuse, dunque: facciamo un giro alternativo, alternando spiagge e falesie e dune a campi e prati, natura al naturale e messinscene iper-reali, castelli fuori misura e atelier d'arte colta.
 
Bordata Studstrup e raggiunta Rønde, il primo campionario del "best of Djursland" si squaderna in fretta ma va esplorato con calma: due boschi urbani (Hestehave e Ringelmose), una chiesa medievale (Bregnet) ed i resti di un castello trecentesco: Kalø, tra leggende vere e verità verosimili, era il più massiccio dei quattro fatti costruire da Erik VI, sovrano visionario e dal pessimo carattere. Si inizia subito dopo a prendere confidenza col profilo della litorale: si spezzetta in anfratti frattali e poi si stende, per ristringersi di nuovo. Succede all'istmo di Dragsmur, una specie di stargate marinaro per entrare nella penisola di Helgenæs. Il faro di Sletterahge è uno dei tanti di questa zona ed esegue alla perfezione il còmpito: si staglia compìto sullo sfondo dei selfie, orienta i navigatori alle prese con navigatore dell'auto a noleggio. E moltiplica i panorami terra-mare-terra, uno su tutti: quello di Lushage è tra i più belli.
 
La città più visitata di tutto il Djursland si intuisce presto oltre la baia, se ci si arriva lungo la litoranea vale però prima la pena rallentare e fermarsi a Femmøller, riviera norrena ben attrezzata.
Djursland, sorprese dal cuore della Danimarca

Djursland (foto VisitDenmark, Mols Bjerge)

Ecco dunuqe Ebeltoft. Si potrebbe tradurre meleto ma i pomi sono sullo sfondo, in primo piano s'impone tutto il parterre dell'oloegrafia più "pittoresca" (sic) e "suggestiva" (sic, bis) che un borgo danese possa esibire. Mica facile, ce ne sono centinaia, curati e tirati a lucido. La cittadina ha però trovato la miscela mirabile e definitiva. Vicoli di ciottoli e lungomare ventoso, porticine e portali e case che sembrano dei modellini a scala invertita e reale capovolto. Idem per i negozi: oltre le vetrine l'artigianale si stempera nell'artistico, regalando dignità ai souvenir e rendendo accessibili le opere più interessanti. Non basta? Se la Grænseløse Køkke ha qualcosa in programma conviene farci un salto, è una specie di bistrot informale tutto piante, panche e hygge in un ambiente della vecchia fabbrica di malto rinominata Ny Malt – è un gioco di parole, sta per "vernice fresca" (letteralmente "verniciato da poco"). Il Glasmuseet è l'elegante contenitore di un "museo attivo per il vetro contemporaneo", l'ha disegnato un ensemble di architetti locali integrando gli ambienti di una struttura doganiera i funzione fiino ad un secolo fa. La collezione permanente conta oltre un migliaio di pezzi, quelle temporanee compendiano, osando, il nuovo che avanza scintillante e in controluce. L'espresso del Glascafé – servito in tazzine speciali, ovviamente – scuote le sinapsi in vista di un giro tra i laboratori dei mastri vetrai della zona (la Glasruten). Torniamo alle mele: se ci si trova in città nella prima settimana di autunno la visita va  prolungata per godersi gli eventi e gli spunti dell'Ebelfestival.
 
Hage è l'ultimo avamposto di torpore, ozio balneare e contemplazione da Instagram (senza filtri, basta aspettare qualche minuto e le viste si saturano, combinando luminiosità improbabilil). Muovendosi verso Gåsehage le cose cambiano: starne e gabbiani competono coi kite-surfers ché il mare inizia qui a farsi meno placido. L'isolotto Hjelm è al largo ed il dilemma costa-entroterra si risolve rapidamente, non ponendoselo affatto. Il reticolo di strade è infatti capillare, perdersi è difficile (sarebbe comunque un bel lusso) e vale la pena seguire l'estro del momento. Qualche indicazione dunque per immaginare un itinerario da cui deragliare. Il lago Stubbe, le tre megaspiagge di Boeslum, Dråby e Holmen fino a Jenrhatten con le sue viste grandiose.

Se si opta per l'interno lontano dal mare – si fa per dire, dal cuore del Djusrland alla costa non si è mai a più di un'ora di guida  da una battigia– ci si confronta con un apparente paradosso, la messinscena della natura: condensa l'esotico declinandolo in tre varianti "moderne" di bioparco – Il Ree Park Safari, lo Skandinavisk Dyrepark e la Randers Regnskov – ed in mezzo c'è anche spazio per l'adrenalina:la garantiscon le attrazioni del Djurs Sommerland con le montagne russe più alte di tutta la Danimarca. Torniamo coi piedi per terra, anzi sul bagnasciuga.

La punta della punta della narice è Grenaa, sorella diversa di Ebeltoft: simile vocazione marittima, diversa miscela di commercio e turismo. Meno patinata ma altrettanto interessante, va esplorata passeggiando lungo gli argini della darsena, dal porto fino al centro ed oltre – continuando si arriva al Lübker Golf Resort, consideerato da molti il migliore del paese – per poi tornare sulla costa e decidere cosa fare.  Si può chiudere il cerchio sul litorale nord mettendo in conto almeno due soste (Gjerrild e Bonnerub) o ritagliarsi un paio di giorni per l'isola di Anholt: quasi interamente areea protetta, è visitabile con "obbligo" di pernottamento.
Tanto prima o poi si rientra ad Aarhus, la capitale #2 al centro della Danimarca. O quasi.
 
 


 
 

19.8.17

Muscle...

http://www.ucam.edu/sites/default/files/Oct_13/mechanisms_of_muscle_hypertrophy.pdf

9 Issues That Plague Various Levels of Swimmers—Solved | Triathlete.com

9 Issues That Plague Various Levels of Swimmers—Solved | Triathlete.com

9 Issues That Plague Various Levels of Swimmers—Solved

Whether you're new to the water, have a few years under your suit or you're a seasoned swimming vet, there's always room to improve your opening leg.

Swimming is a sport of nuances. You've heard that before. Much more so than cycling or running, swimming well requires the right combination of body position and limb movement to get through the water efficiently. And since water is 784 times denser than air, even tiny faults in your stroke can have a big impact on your speed and efficiency.

Making matters worse, it's impossible to fix everything that's ailing your stroke at the same time. You can't focus on swimming with high hips, improving core rotation and proper hand placement all at once. The first step toward overhauling your stroke is to first find that one thing holding you back, and then spend the necessary time in the pool to address that issue.

We asked two of triathlon's top swim coaches to address the nine issues that most often plague beginner, intermediate and advanced swimmers. Check them out, then get in the pool and go to work.

Beginner issues

1. Fear of the open water

How can I get past the mental and physical challenges of swimming in the open water surrounded by hundreds of other nervous athletes? 

"Fear is generally derived from a lack of familiarity," says open-water expert Gerry Rodrigues, who leads a Los Angeles-based swim training program called Tower26. When coaching beginner swimmers, Rodrigues uses the three F's: moving from fear to familiarity through frequency. "Incorporating specific simulation drills during regular pool workouts, and doing it over and over again, really helps," he says.

Four of Rodrigues' favorite simulation drills are: swimming three or four abreast in a single lane; using frequent sighting during all workouts; pace-line swimming to get used to swimming on another athlete's feet and having your own feet grabbed; and race-start speed drills to become more comfortable with the intensity at the start of the swim.

2. Sinking hips
I feel like I'm dragging my entire lower body through the water. How do I learn to swim with high hips? 

"This is a proprioception situation whereby athletes need to grasp an awareness of which muscle groups to engage and at what effort," Rodrigues says. "The objective is learning to keep the body taut when in a horizontal plane, with three touch points connected to the water's surface: the back of the head, the butt and the heels."

Rodrigues has four favorite drills to help achieve proper hip position:

Kicking with a board and snorkel (with the board extended and your face in the water) to learn how to kick with the head, butt and heels on the surface.

Vertical kicking (kicking upright in the deep end): "This is a very important drill for learning body awareness," he says.

As much pulling as the athlete can handle. He recommends using a pull buoy, ankle strap and snorkel to pull with proper body position.

Short and fast intervals, like 25s and 50s, which force the body into a more taut posture.

3. Shoulder pain
One shoulder always hurts when I ramp up my swim yardage. It's never in both shoulders, but there's always pain the day after a big session in the pool. What's going on? 

Unless there's an acute issue in the rotator cuff or AC joint, shoulder soreness or stiffness is often indicative of a problem with the larger muscle groups used in swimming, like the lats and chest, not being engaged properly. "Start by looking at some common swim errors such as crossing over at the midline, or the hand slipping out after entry and pulling wide," says elite triathlon coach and Arizona State University head tri coach Cliff English. These seemingly minor miscues can put more stress of the rotator cuff and deltoid muscles. Once the error is identified, it's then time to address it through awareness, drill work and possibly some dry-land strength exercises. "Also, it may help to lay off of the giant, trash can lid paddles," he adds.

Intermediate issues

4. Pulling nothing
I feel like my hands and arms aren't pulling much water. What techniques and drills should I try to improve my feel of the water and create a stronger pull? 

"It's very common for swimmers to have the feeling of 'spinning their wheels' with regard to the catch and pull phases of freestyle," says English. He recommends swimming with both a snorkel and fins so that swimmers don't have to focus on kicking and breathing and can instead devote their complete attention to the catch and pull phases of their stroke. English also suggests incorporating "feel" drills, such as sculling with arms extended while using a snorkel, as well as the closed-fist drill, which helps swimmers learn to pull with their forearms as well as their hands.

5. Breathing too long
My stroke feels great except for when I breathe. I feel like I stick too much of my face out of the water and take too long to complete each breath. How can I fix my breathing so that there's a better rhythm to my stroke? 

According to Rodrigues, breathing issues are usually symptomatic of another problem. Most often, an extra long breathing cycle is caused by holding one's breath too long (i.e., releasing the air too late before the next breath), or over-rotation of the hips and torso when turning to breathe.

Rodrigues recommends two easy drills to fix this issue. "Try a simple inhale and exhale exercise against the pool's wall in a vertical position," he says. "Inhale, place your head underwater, and then exhale immediately to return to the surface and repeat." To prevent over-rotation, try a one-arm drill while holding a kickboard from the bottom of the board. "An extended arm holds the board while the other arm executes the stroke. Then alternate arms and breathe every one or three strokes," he says.

6. Pacing poorly
I go out too hard at almost every race—I can't seem to control the nervous excitement. Then I'm winded after 400 meters and my pace really suffers for the rest of the swim. How do I learn to settle in instead of blowing up at the start? 

"Race-specific training is the only way to mitigate this issue," Rodrigues says. Many swimmers train specifically for even, steady-state pacing but forget how to do that come race day because of excitement and nerves.

"We have to add the element of take-out speed into training sessions with frequency and then allow time for adaptation," he says. One of his favorite workouts to do this is 8–10 x 400 (100 race take-out speed with two sightings per lap/300 at regular race pace with one to two sightings per lap).

"It's extremely important to incorporate frequent sightings into these types of workouts, because it can add a lot of fatigue or discomfort if it's not practiced prior to race day," Rodrigues adds.

Advanced issues

7. Unilateral breathing
I only breathe to my right side. It's the way I've always done things, and I know I'm faster if I only breathe to one side. Am I missing out on something by not breathing to both sides, and how much bilateral breathing should I incorporate into my workouts? 

"Adding in some bilateral breathing intervals or drills helps develop good symmetry in your stroke and also gives you time to 'observe' your stroke and become more aware of what you're doing in the water," says English. He recommends incorporating bilateral breathing into the warm-up and cool-down portions of workouts, as well as during any technical portions like drills and pulling. Most advanced swimmers will be faster when breathing only to their dominant side, so it's still OK to breathe only to that side for hard efforts during the main set of a workout.

"Being able to breathe on both sides is also a good skill to have during races, when sighting or being able to orientate yourself in a group can be a big advantage," he adds.

8. Ignoring the draft
I grew up swimming in a pool, and I'm a little uncomfortable swimming in a pack in the open water. I prefer to have clean water in front of me, and I'm usually fast enough to get out in front of a group on race day. Am I missing out on something by not drafting, and what's the ideal distance to hang off of someone's feet?

According to Rodrigues, a lack of comfort with drafting is simply due to a lack of experience. "Change the experience, and the outcome changes," he says. Introduce training sessions that focus specifically on drafting, side-by-side swimming and pace-line efforts, all of which can be done during a typical pool workout. It's important for triathletes to incorporate some form of group swimming into every session, especially during the race season.

Rodrigues has also spent time measuring the benefit of drafting using a velocity meter and found that drafting off the hip of the athlete in front yields by far the greatest benefit. "Drafting off the hip accounted for approximately an 8.5 percent benefit. Immediately on the feet yielded between a 3 and 3.5 percent benefit," he says. He noted that the reduction in drag dropped significantly when a swimmer fell one meter behind the athlete in front, and at two meters behind there was almost no benefit at all.

9. Only using paddles
There are a lot of swim toys out there. I just have paddles. Should there be something else in my pool bag, and how much should I use other things? 

"Not every piece of equipment works for every swimmer," English says. "The question to ask is, 'Why use this tool?' The answer should not be because it makes things easier."

According to English, fins are a key "toy" that should be in every swimmer's bag. They can help maintain a good body position while tweaking more challenging parts of the stroke, like the catch, pull, recovery and hip position. He also recommends a snorkel, which is a valuable tool for developing a symmetrical stroke. "Used along with fins, this can be a great combo," he says.

English uses caution when it comes to paddles, however. Especially for new swimmers or those with shoulder issues, he advises against them because they might alter their stroke or cause greater shoulder problems. Of course, there's the tried and trusted kickboard—something that should be in every swim bag, regardless of an athlete's ability.

Mad Fientist's early-retirement spreadsheet - Business Insider

Mad Fientist's early-retirement spreadsheet - Business Insider

A man who retired at 34 shares a spreadsheet that helped him get there

brandon mad fientist.JPGBrandon, also known as the Mad Fientist.Courtesy of Mad Fientist.

On August 1, 2016, Brandon officially retired.

The 34-year-old software developer and blogger behind the Mad Fientist — who doesn't use his last name online for privacy reasons — had been planning and saving for years to retire early.

"For the first five to seven years of my career, I wasn't saving for anything in particular," Brandon told Business Insider. "I was just saving because I wanted a portfolio. Then I learned about financial independence, and I was like, 'This is perfect. This is what I'm saving for.'"

Brandon, who is married but keeps his finances largely separate from his wife, Jill, an optometrist who isn't interested in retiring, was talking about the concept of financial independence as pursued and documented by an online community of bloggers and readers seeking to save enough that they can stop working and "retire."

Living frugally and working in rural Vermont, he managed to save and invest about 70% of his after-tax income, and saved enough to leave his job in spring 2014. However, when he approached his employer with the news he'd be moving to Scotland to be closer to his wife's family, the employer offered to make his position remote.

That change eliminated all of the things that frustrated Brandon most about working life, like commuting, dealing with difficult coworkers, and navigating endless meetings. So he stayed on for a few years more than planned, intermittently traveling with Jill until they relocated full time to Scotland in May 2015. There, he continued working, blogging, and saving until he retired this summer.

"It's always been about 'financial independence' for me and not really 'early retirement,'" he told Business Insider. "I never wanted to stop working, but rather I wanted to have the time and freedom to work on things that are important to me.

"It's a very powerful position to be in, to be able to do things without worrying about the monetary reward, so I imagine I'll be more productive and make a far greater impact on the world now that I don't have to trade my time for money and don't have money driving my decision-making."

On Mad Fientist, Brandon offers a free, downloadable Excel spreadsheet to help others calculate when they can afford to retire. It's not the exact one he uses — since he built this version in 2014, he's made some tweaks to his own — but lays out the most important factors, accounts, and balances he's been tracking for years.

Bear in mind that the numbers in the sheet are not his actual numbers, which he does not share. These numbers are for example purposes only.

The blue cells are the ones people can edit (on the interactive version from the website — below are screenshots that don't accept data) to input their numbers.

He walked Business Insider through the spreadsheet:

View As: One Page Slides

18.8.17

High intensity interval resistance training (HIIRT) in older adults: Effects on body composition, strength, anabolic hormones and blood lipids

High intensity interval resistance training (HIIRT) in older adults: Effects on body composition, strength, anabolic hormones and blood lipids

High intensity interval resistance training (HIIRT) in older adults: Effects on body composition, strength, anabolic hormones and blood lipids

  • Tatiana Moroa, b, c, ,
  • Grant Tinsleyd, ,
  • Antonino Biancoe, ,
  • Angela Gottardia, ,
  • Gio Batta Gottardif, ,
  • Diego Faggiang, ,
  • Mario Plebanig, ,
  • Giuseppe Marcolina, ,
  • Antonio Paolia, ,
https://doi.org/10.1016/j.exger.2017.08.015
Get rights and content

Highlights

•

High intensity interval resistance training (HIIRT) can be safely performed by older individuals.

•

HIIRT could reduce basal insulin, total cholesterol, LDL and TGs levels.

•

HIIRT could help to maintain lean body mass in older adults.

Keywords

  • Elderly;
  • Resistance training;
  • Body composition;
  • Strength;
  • Blood lipids;
  • High intensity

1. Introduction

The aging process induces significant changes in skeletal muscle morphology and functionality. If not counteracted, this process, termed sarcopenia, can lead to progressively greater disability, frailty and loss of independence. Whilst determining the prevalence of sarcopenia at the population level is complicated by different diagnostic criteria and methodologies used to assess muscle mass, a large percentage of older adults will suffer from this condition in their lifetime (von Haehling et al., 2010). Additionally, longer life expectancy is producing a growing number of elderly individuals worldwide (). Therefore, age-related diseases, such as sarcopenia, are an increasingly important public health concern, and optimal strategies for combatting the progressive loss of muscle mass and function are needed.

It is well known that performing regular resistance training (RT) can counteract sarcopenia and improve fitness and body composition (Raymond et al., 2013 ;  Steib et al., 2010). The American College of Sports Medicine (ACSM) and American Heart Association (AHA) physical activity recommendations for older adults encourage progressive weight training at least 2 days per week at a subjective intensity corresponding to "moderate" to "vigorous" (i.e. an intensity of 5–6 to 7–8 on a scale of 0 to 10) (). ACSM has also put forth a position stand advocating the usage of loads corresponding to 60–80% of the 1-repetition maximum (1RM) for 8–12 repetitions with 1–3 min of rest between sets in healthy older adults ().

In addition to counteracting sarcopenia through maintaining or increasing muscle mass and strength, RT can improve functional abilities and combat a variety of other disease states, including cardiovascular and metabolic diseases, depression, and osteoporosis (). Implementing a RT program can lead to beneficial modifications of blood lipid components in the elderly, such as reductions in LDL cholesterol and increases in HDL cholesterol (). Whilst a variety of RT programs may be beneficial, most previous investigations have not employed direct comparisons of the efficacy of different RT programs in the elderly. Although it seems that higher intensities (> 80% 1RM) lead to greater improvements in muscular strength and muscle mass in the elderly (), the effects on other physiological parameters are less clear. Perhaps due to the numerous variables involved in RT programming, the differences between training styles in the elderly are not completely understood and warrant further investigation (). Although utilizing 60–80% of the 1-repetition maximum (1RM) for 8–12 repetitions with 1–3 min of rest between sets is the suggested training protocol for healthy older adults (), other methods utilizing shorter incomplete rest periods could be a more time-efficient strategy. A recent meta-analysis has demonstrated that lack of time and interest, as well as post-exercise soreness, is a major factor contributing to attrition of elderly individuals undergoing exercise training (). Developing a training protocol that is feasible enough to keep older adults training consistently, but intense enough to promote muscular improvements, should be a goal of researchers interested in the prevention of sarcopenia and the related functional limitations. A resistance training based technique that fits these requirements is the rest-pause technique and its variants (). Rest-pause techniques involve a pause (that may vary in duration) between a certain number of repetitions within a set (Keogh et al., 1999; Korak et al., 2017 ;  Marshall et al., 2012). We previously investigated the effect of a variant of the rest-pause technique, called high-intensity interval resistance training (HIIRT), on metabolism in young adult males ().

The aim of this study was to assess the effects of two different RT programs on muscle strength, body composition, anabolic hormones and blood lipids in older adults. Specifically, a traditional resistance training (TRT) program conforming to ACSM recommendations (i.e. 3 sets of 8 repetitions at 75% 1RM with 90 s rest periods) was compared to high-intensity interval resistance training (HIIRT; 2 sets of 6/2/2 repetitions with incomplete rest periods of 20 s within the set).

2. Methods

2.1. Participants

2.1.1. Recruitment

Fifty subjects were recruited through advertisement in newspaper and medical studios in the metropolitan area surrounding the University of Padova. Screening procedures included a health history questionnaire and a medical visit, and individuals with any musculoskeletal, cardiovascular, metabolic, inflammatory or neurodegenerative diseases were excluded. Subjects undertaking hormonal replacement therapy were also excluded. Only individuals who were between the ages of 60 and 80 years, with a BMI lower than 30 and no prior resistance training experience were allowed to participate.

After providing written informed consent and completing the medical history visit, all subjects performed a stress test under the supervision of a cardiologist to evaluate any cardiac abnormalities that would prevent their participation in the study.

Thirty-five older adults (15 female and 20 male) were included in the study ().

Fig. 1.
Fig. 1. 

CONSORT (Consolidated Standards of Reporting Trials) diagram of study recruitment, enrollment, randomization follow-up, and analysis.

2.1.2. Randomization

The participants (males and females) were randomized to either TRT (N = 17) or HIIRT (N = 18) using on-line QuickCalcs (http://www.graphpad.com/quickcalcs/randomize1.cfm) by GraphPad Software, San Diego, California.

2.1.3. Ethics

All subjects were informed about the purpose and risks of the study and provided written informed consent in accordance with the Declaration of Helsinki. The study was approved by the local ethical committee of the Department of Biomedical Sciences (University of Padova).

2.2. Experimental approach and study design

The intervention was divided in two phases (). During the first 4 months, all the subjects performed the same progressive resistance training program, starting with 3 sets of 15 repetitions at 60% of 1RM for each exercise and progressing to 3 sets of 10 repetitions at 70% 1RM. After the 4-month familiarization period, subjects started the intervention period, which lasted 2 months. Subjects were randomized into high intensity interval resistance training group (HIIRT) or traditional resistance training group (TRT) group. Subject characteristics after the randomization are shown in .

Fig. 2.
Fig. 2. 

Study design. After 4 months of progressive resistance training subjects were randomly divided in the two experimental groups: high intensity interval resistance training (HIIRT) and traditional resistance training (TRT). BIA = Bioelectrical Impedance Analysis, 1 RM = 1 repetition maximum.

Table 1.

Anthropometric characteristics of subjects after randomization to the specific RT protocols. Data are presented as mean ± SD. BMI = Body Mass Index, FFM = Fat Free Mass.

TRT
(N = 17)
HIIRT
(N = 18)
Age (years)61.7 ± 4.264.1 ± 2.3
Weight (kg)72.4 ± 14.670.3 ± 10.5
BMI (kg/m2)25.7 ± 3.625.5 ± 2.5
FFM (kg)36.8 ± 5.936.5 ± 7.2

The rationale behind the long (4 months) period before randomization comes from necessity of gradually progressing through the neuroadaption stage that normally occurs in the first weeks or months of resistance training in previously untrained individuals (Moritani and de Vries, 1979 ;  Seynnes et al., 2007) and to let all the subjects achieve the experience necessary to complete the higher intensity experimental protocol without muscular injury.

Before and after the training period, Bioelectrical Impedance Analysis (BIA), blood test analysis and strength tests (1RM) were performed. Muscular strength tests were also repeated before the randomization process to ensure equivalent baseline strength between groups prior to the intervention period.

2.3. Measurements

Before and after the training period, all subjects participated in the same testing visit. All subjects were instructed to arrive fasted and not to perform any exercise for 8 h before the testing. On the test day, participants arrived at the laboratory around 8:00 am.

2.3.1. Anthropometry and body composition

Height and body weight were measured with a digital electronic scale (Tanita BWB-800 Medical Scales, Tanita Co. Arlington Heights, IL, USA), and body composition was assessed using bioelectrical impedance analysis (BIA, Akern Bioresearch, Pontassieve, FI, Italy). BIA is a reliable, safe, convenient, and non-invasive method that provides estimations of fluid compartments, fat and fat-free mass in healthy subjects (Frisard et al., 2005; Kushner et al., 1990; Paoli et al., 2013a; Piccoli et al., 2007 ;  Stewart and Hannan, 2000). Through the analysis software, we obtained the values of fat free mass (FFM) and fat mass (FM).

2.3.2. Blood biochemistry

Blood samples were taken from antecubital vein and collected into BD Vacutainers Tubes (SST™ II Advance, REF 367953). After blood sampling, samples were centrifuged (4000 RPM at 4 °C using centrifuge J6-MC by Beckman), and the serum was aliquoted and stored at − 80 °C. All samples were analysed in the same analytical session for each test using the same reagent lot, and the intraassay CV was < 7% for all analyses. Before the analytical session, the serum samples were thawed overnight at 4 °C and then mixed. Testosterone, cortisol, growth hormone (GH), insulin-like growth factor-1 (IGF-1), IGF-binding protein-1 and 3 (IGFBP1 and IGFBP3), lipoproteins, insulin, glycaemia, alanine aminotransferase (ALT), aspartate transaminase (AST), gamma-glutamyl transferase (GGT), creatine kinase (CK), creatinine, uric acid and urea were determined. Total testosterone was measured by immunochemiluminescent method (Roche Cobas e601, Roche Diagnostics, Mannheim, Germany), blood glucose by enzymatic method with esokinase (Roche Cobas e702, Roche Diagnostics, Mannheim, Germany), total cholesterol, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL) and GGT by enzymatic colorimetric in homogenous phase (Roche Cobas e702, Roche Diagnostics, Mannheim, Germany), triglycerides (TGs) and uric acid by an enzymatic colorimetric method (Roche Cobas e702, Roche Diagnostics, Mannheim, Germany). ALT and AST were measured by pyridoxal phosphate activation according to IFCC, GGT was measured by a IFCC and Szasz standardized enzymatic colorimetric method, CK and Urea by kinetic enzymatic method, creatinine by enzymatic (Roche Cobas e702, Roche Diagnostics, Mannheim, Germany). Apolipoprotein A-1 (APOA1) and Apolipoprotein B (APOAB) were measured by immunophelometric system (Dimension VISTA, Siemens, Healthcare Diagnostics Ltd., Camberley, UK). Free testosterone was determined by RIA (radioimmunological manual method) (Beckman Coulter) and IGFBP3 and IGFBP1 by IRMA (Dia Source). IGF-I was measured using the analyzer Liaison XL (DiaSorin S.p.A, Vercelli- Italy). The test is a sandwich immunoassay based on a chemiluminescent revelation. Insulin was measured with a chemiluminescent immunoassay (Siemens Immulite 2000).

After the blood draw, subjects were then familiarized with the strength testing protocol and the exercises used in the training program.

2.3.3. Strength

Strength was measured via a 3–6 RM strength test for the major trained muscle groups (leg extension, chest press, latissimus pull down and arm curl). After an appropriate warm up for each test, weight was gradually increased until failure occurred between a range of 3–6 repetitions, which were performed using correct technique and without assistance. A 3–6 RM test was chosen because it is suitable to test maximal strength in subjects with little or no previous resistance training experience (), and this technique has been shown to have a high reproducibility (r = 0.99) in our lab ( Paoli et al., 2012 ;  Paoli et al., 2013b). Using the results of the strength testing, 1RMs were estimated with Brzycki formula (): 1 RM (estimated) = load (kg) / [1.0278 − (0.0278 × number of repetitions)]. Data obtained from initial strength testing was used to determine appropriate loads at the beginning of the resistance training program.

2.4. Training protocol

Training sessions were performed twice a week and included: chest press, lat pulldown, military press, bicep curls, triceps extensions, leg press, leg curls and sit-ups. During the first 4 months, training intensity gradually increased to reach 70% of 1RM, as estimated by the first strength test. After the 4-month training period, a new 3–6 RM strength test was performed to determine the appropriate level for the two intervention protocols. One group used a modified rest-pause method called HIIRT, as previously described (Paoli et al., 2012; Paoli et al., 2011; Paoli et al., 2010 ;  Paoli et al., 2013b). For each exercise, the HIIRT technique consisted of two series of the following: 6RM at 80% 1RM followed by 20″ of rest, repetitions to failure with the same weight, another 20″ of rest, and repetitions to failure (2–3 repetitions) using the same weight again (). After 2′30″ rest, subjects repeated the entire sequence a second time (i.e. the second series was performed). The entire training session lasted approximately 45 min, including the warm up and cold down periods.

The TRT group performed three sets of eight repetitions at 75% of 1RM, with 2′30″ of rest between sets. The training session lasted approximately 65 min, including the warm up and cold down periods. Training volume of the two different protocols was similar. For example, assuming that the 1RM of the subjects was 100 kg, with HIIRT protocol the total volume of training (set × reps × load) was about 1760 kg (2 × 6 + ~ 3 + ~ 2 × 80 kg), whilst with TRT was 1800 kg (3 × 8 × 75 kg). HIIRT volume may have differed slightly from subject to subject, as participants were requested to perform repetitions to failure (typically 2–4 repetitions) after the first six reps at 80% 1RM ().

Fig. 3.
Fig. 3. 

Training protocols. HIIRT protocol consisted of 2 series at 80% 1RM in which subjects were instructed to perform repetitions to exhaustion three different times in each series, with 20″ rest between the 1st and 2nd efforts and the 2nd and 3rd efforts. Subjects were allowed to rest 2′30″ before starting the second series. TRT protocol consisted of 3 series of 8 repetitions at 75% 1RM, with 2′30″ rest between sets. Both resistance training protocols utilized the same methods for progression.

A certified personal trained supervised all sessions in order to ensure safety and proper execution of the training program.

2.5. Statistical analysis

Data are expressed as means ± SD. Statistical analysis was performed with GraphPad Prism 6.0 software (GraphPad Software, San Diego, California). Through the Shapiro-Wilk's W test, we assessed the normality between groups. An independent samples t-test was used to test baseline differences between groups. Within-group effects were analysed using one-way ANOVA. The effects of training were analysed using a two-way repeated measures ANOVA (time × treatment); in case of significant main effects or interactions, Bonferroni post hoc test was performed. Standardized differences between pre-post interventions were obtained through Cohen's effect size. Significance was set at p < 0.05.

3. Results

A total of 35 subjects were included in the study and divided randomly into two groups: traditional training (TRT; N = 17) and high intensity interval resistance training (HIIRT; N = 18). During the two-month intervention period, 8 subjects dropped out of the study from TRT (− 47%) whilst only 4 subjects dropped out of the study from HIIRT (− 22%), indicating superior retention with the high intensity protocol compared to traditional resistance training.

Strength increased with both training protocols (p < 0.001), without any significant difference between the two programs (). HIIRT and TRT both showed large Cohen's effect size (ES) for leg extension strength (0.818 and 1.138, respectively). For chest press strength, ES were also large in HIIRT (0.957) and TRT (0.736). Lat pulldown strength ES was large in HIIRT (1.103) and small in TRT (0.455). Arm curl strength ES were large in both cases (1.840 in HIIRT and 1.787 in TRT).

Table 2.

Strength test and body composition results. Values are presented as mean ± SD.

TRT (N = 9)
HIIRT (N = 14)
PrePost%PrePost%
Strength test 1RM
 Leg extension (kg)#50.8 ± 13.867.7 ± 15.8⁎+ 36%54.7 ± 14.268.5 ± 19.1⁎+ 27%
 Chest Press (kg)38.7 ± 15.449.9 ± 14.9⁎+ 33%46.4 ± 14.559.1 ± 12.1⁎+ 32%
 Lat Pulldown (kg)51.8 ± 13.158.2 ± 15.1⁎+ 12%54.6 ± 11.366.9 ± 11.0⁎+ 24%
 Arm Curl (kg)16.7 ± 5.325.7 ± 4.7⁎+ 51%22.6 ± 4.530.4 ± 4.4⁎+ 40%
Body composition
 Body Weight (kg)70.4 ± 13.870.2 ± 13.6− 0.3%69.5 ± 11.169.3 ± 10.9− 0.3%
 Fat Free Mass (kg)37.6 ± 7.235.8 ± 6.7⁎− 5%36.5 ± 5.135.7 ± 5.4− 2%
 Fat Mass (kg)37.7 ± 12.238.6 ± 13.4⁎+ 5%33.0 ± 7.733.8 ± 6.7+ 3%
⁎

Significantly different from baseline.

#

Significantly different between groups, p < 0.05.

Bioelectrical impedance analysis showed a significant decrease of total FFM (− 5%) and a significant increase of FM (+ 5%) only of TRT groups, whilst HIIRT showed no significant changes (). Body weight showed a small ES for both groups TRT (0.0145) and HIIRT (0.0181), also fat free mass showed a small ES for TRT (0.2588) and HIIRT (0.1523). Finally, fat mass ES resulted also small (0.0702) in TRT and small (0.1108) in HIIRT.

Concentrations of hormones in the blood are displayed in . Cortisol concentrations were higher after training in both groups (TRT + 8% and HIIRT + 14%), although this was only statistically significant in HIIRT. IGF-1 decreased in both groups but without differences between groups, whilst insulin decreased significantly only in the HIIRT group (− 29% vs. − 11% in TRT). Basal GH levels decreased significantly in TRT (− 78%), but not HIIRT (− 30%). Circulating concentration of testosterone was also analysed by gender: no significant differences were observed in males (TRT + 6%, HIIRT + 7%), whilst females experienced a significant improvement from basal condition without differences between training groups (TRT + 64%, HIIRT + 24%) ().

Table 3.

Hormonal results. Values are presented as mean ± SD. GH = Growth Hormone, IGF-1 = Insulin Growth Factor 1, IGF-BP1 = Insulin Growth Factor Blinding Protein 1, IGF-BP3 = Insulin Growth Factor Blinding Protein 3.

TRT
HIIRT
PrePostPrePost
Cortisol (nmol/L)395.44 ± 97.51425.11 ± 100.96390.21 ± 100.00443.36 ± 85.13⁎
GH (ng/ml)2.39 ± 2.570.53 ± 0.59⁎3.05 ± 4.742.13 ± 4.41
Insulin (ɯU/ml)7.32 ± 3.816.51 ± 3.068.50 ± 5.956.01 ± 2.79⁎
IGF-1 (ng/ml)160.00 ± 40.23135.26 ± 36.34⁎155.80 ± 25.93132.08 ± 20.38⁎
IGF-BP1 (ng/ml)3.93 ± 2.874.17 ± 2.492.91 ± 3.324.33 ± 2.50⁎
IGF-BP3 (ng/ml)4269 ± 1000.693634.67 ± 1236.98⁎4553.93 ± 685.734127.36 ± 876.45⁎
Free Testosterone (ng/ml)
 Male25.60 ± 8.0828.20 ± 7.8227.25 ± 7.8730.38 ± 8.72
 Female3.40 ± 0.735.18 ± 1.52⁎4.78 ± 0.926.05 ± 0.99⁎
Total Testosterone (ng/ml)
 Male12.57 ± 2.3813.34 ± 3.5714.52 ± 4.9315.55 ± 6.19
 Female0.32 ± 0.230.52 ± 0.31⁎0.68 ± 0.460.84 ± 0.41⁎
⁎

p < 0.05 pre vs. post (main time effect).

Fig. 4.
Fig. 4. 

Changes in estimated 1 RM after 6 months of training, divided by male and female. Changes are showed as percent change from baseline.

Interestingly, both groups improved their lipid profile (), but only HIIRT elicited a significant (p < 0.05) improvement of total cholesterol (HIIRT − 9%), cholesterol LDL (HIIRT − 11%) and triglycerides (HIIRT − 18%).

Table 4.

Blood biochemistry results. Values are presented as mean ± SD. APOA1 = Apolipoprotein A-1, APOB = Apolipoprotein B, CHOL = total cholesterol, HDL = high-density lipoprotein cholesterol, LDL = low-density lipoprotein cholesterol, TG = tryglicerids, ALT = alanine aminotransferase, AST = aspartate transaminase.

TRT
HIIRT
PrePostPrePost
APOA1 (g/L)1.66 ± 0.321.63 ± 0.341.73 ± 0.221.65 ± 0.22*
APOAB (g/L)1.05 ± 0.230.94 ± 0.19*1.00 ± 0.170.88 ± 0.16*
CHOL (mmol/L)5.73 ± 1.195.30 ± 1.025.56 ± 0.655.07 ± 0.78*
HDL (mmol/L)1.56 ± 0.531.54 ± 1.021.66 ± 0.371.63 ± 0.40
LDL (mmol/L)3.87 ± 1.023.47 ± 0.823.65 ± 0.663.24 ± 0.66*
TG (mmol/L)1.51 ± 0.871.42 ± 0.551.20 ± 0.660.99 ± 0.44
Glucose (mmol/L)5.61 ± 1.095.89 ± 2.665.62 ± 0.815.07 ± 0.50
ALT (U/L)22.33 ± 10.2022.33 ± 5.8330.57 ± 21.5425.07 ± 8.64
AST (U/L)27.22 ± 5.9324.00 ± 3.2831.79 ± 13.5923.29 ± 5.34*
Gamma GT (U/L)19.22 ± 11.0720.33 ± 12.6726.93 ± 9.6126.79 ± 10.40
Creatine kinase (umol/L)119.11 ± 62.03113.44 ± 39.83110.08 ± 42.73127.85 ± 57.63
Creatinine (umol/L)70.78 ± 8.2974.56 ± 8.8075.71 ± 9.1981.29 ± 6.27*
Uric acid (mg/L)0.29 ± 0.050.31 ± 0.060.31 ± 0.080.33 ± 0.08*
Urea (mg/L)6.09 ± 1.686.13 ± 2.075.92 ± 0.826.29 ± 1.09
⁎

p < 0.05 pre vs post (main time effect).

4. Discussion

We have previously demonstrated that, in an acute setting, high intensity interval resistance training (HIIRT) is able to increase EPOC in the 22 h following the training session in young healthy adults (). These promising data were confirmed subsequently in a group of overweight middle-aged subjects performing HIIRT alternating with a HIT-like protocol (8′ of endurance on cycloergometer performed for 3′ at 50% and 1′ at 75% of HRR) in a 12-week study (). We demonstrated that the high intensity circuit exerted a greater positive effect on blood lipids compared to a constant endurance protocol or lighter circuit training. Moreover Romero-Arenas and colleagues () showed that a high-resistance circuit training improves cardiovascular system variables and decreases fat mass. Thus, in the present study we sought to investigate the effects of an HIIRT in an elderly population. Our data showed that HIIRT protocol was at least as beneficial as a traditional resistance protocol for strength improvement and body composition, whilst HIIRT produced a greater increase of testosterone in females, a less pronounced decrease of GH and superior modulation of blood lipids.

The lack of significant differences between groups for body composition is somewhat surprising considering our previous results. Nevertheless, an examination of our data indicates that TRT lost muscle but also increased fat mass whilst changes were not significant in the HIIRT group. The population in the present study was somewhat different from our previous subjects (e.g. lower body mass). Regarding fat mass, it seems that the intensity performed by our older adults during HIIRT may not have been great enough to elicit significant fat loss (contrary to our previous studies (Paoli et al., 2012 ;  Paoli et al., 2013b)), but was intense enough to prevent fat gain compared to TRT group.

Regarding muscle, it is well known that muscle mass is difficult to maintain during the aging process (). The total training volume was similar between the two groups: 1760 kg for TRT and 1800 kg for HIIRT. This fact could explain the lack of significant differences between HIIRT and TRT in terms of muscle mass, even though some authors suggest a role of high intensity RT on muscle hypertrophy (). Anyway it should be taken into account that it could be a relative reduced response of older individuals to high intensity resistance training. Indeed, our data are in accordance with Kumar and colleagues (), supporting the idea that protein synthesis is blunted at higher training intensity (> 60% 1 RM) in older adults, although recent research has suggested otherwise (). Although the classical anabolic pathway (IGF1/AKT/mTOR) seems to be unaffected, other protein synthesis/degradation machineries could be key factors involved in the process of muscle loss (). Our recent data suggest that drastic activation of the IGF1-Akt pathway may be counterproductive in the elderly (). The present research showed a decrease of basal IGF-1 in both groups without a difference between groups, a significant decrease in both groups of IGFBP3 and a significant increase of IGFBP1 only in HIIRT group. In older adults, low levels of IGF-1 and GH are correlated to a high risk of metabolic syndrome (), but in our subjects the lowering of IGF-1 was counterbalanced by a significant decrease of IGF-1 BP3. Higher levels of IGFBP3, which reduce bioavailability of IGF1, have been correlated with higher cardiovascular risks (). However, HIIRT produced a significant increase of IGFBP1. Reductions in IGFBP1 have been suggested as a marker of insulin resistance, and have been correlated with a greater carotid media thickness in type 2 diabetes (). Integrating the body composition and hormonal data, the results of our research seem to suggest that the effects of the IGF1 reduction was blunted by a decrease of IGFBP3 with a maintenance of fat free mass (superior in the HIIRT group) and fat mass.

Both groups increased strength after 6 months of training without any significant differences between treatments and between gender.

A major result of the present investigation confirmed our previous findings, which indicated beneficial effects of HIIRT on blood lipids parameters (). HIIRT subjects experienced significant improvements in total cholesterol (− 9%) and LDL (− 11%) compared to TRT (). Even though it has been demonstrated that total cholesterol, HDL and triglyceride levels can be improved through regular resistance training in middle-aged subjects (), the precise dosage of RT intensity necessary to produce these changes is still unclear (Paoli, 2012a ;  Paoli and Bianco, 2012). Exercise intensity might be a key factor in blood lipids' exercise response (). The total energy expenditure seems to have a direct correlation with the changes in lipids and lipoproteins, i.e. changes in blood lipid and lipoprotein concentration depends on total amount of calories expended (). We demonstrated higher excess post exercise oxygen consumption (EPOC) after a HIIRT session compared to traditional resistance training (). In general, RT seems to positively affect the blood lipids parameters HDL, LDL and TG (Bemben and Bemben, 2000; Dalleck et al., 2009; James et al., 2016; Kelley and Kelley, 2009; Pitsavos et al., 2009 ;  Ribeiro et al., 2016), even though the exact underlying mechanisms are not well understood (). A recent 1-year study showed significant improvements of cholesterol values, specifically LDL cholesterol, total cholesterol and non-HDL cholesterol, as a result of resistance training (). Stimulation of PPAR-γ and PGC1-α pathways has been suggested as possible mechanisms for the improvement in lipid profile (), as well as reduced LDL formation from VLDL precursors or an improved hepatic removal activity. In accordance with James et al.'s data (), we did not find a significant decrease of TG, suggesting an increased hepatic uptake and clearance. HDL showed no modification, but its response to RT appears to be quite variable considering conflicting results in literature with no change (James et al., 2016 ;  Kim and Kim, 2013), increases (Fahlman et al., 2002 ;  Paoli et al., 2013b) or decreases () reported. In the present study, no significant changes of HDL were observed, which could be explained by the absence of aerobic training, such as was performed during our previous study (). The HIIRT group showed a significant decrease of APOA1, whilst both interventions produced a decrease of APOAB. The APOB/APOA1 ratio decreased significantly by 8% in TRT and 7% in HIIRT, without any statistical significant difference between the two groups, suggesting a general positive effects of resistance training on this parameter. No differences in basal blood glucose were observed after the training period, but this result is not surprising considering that our subjects were not diabetics. However, insulin decreased significantly in HIIRT group after 6 months of training, which may suggest an improvement in insulin sensitivity (IS) related to RT intensity. Indeed, other researchers found no effect of RT alone on IS (Bateman et al., 2011 ;  James et al., 2016), whilst improvement of IS has been reported after combined training (i.e. aerobic plus resistance training) (). The impact of RT intensity remains an open question: it is possible, as suggested in a previous discussion (), that low intensity RT () may not elicit an adequate stimulus for some adaptations. Instead, a higher intensity RT may lead to the related physiological responses such as an increase of myokines, cytokines () and other proinflammatory molecules, or to the downstream molecule AMPK (). RT could also stimulate AMPK and proteins regulating glucose uptake (p-AS160) (). These mechanisms could explain the improvement of IS observed in HIIRT group.

Whilst testosterone concentration (both free and total) did not differ when all participants were analysed together, HIIRT females showed a significant increase of both free testosterone and total testosterone (respectively + 26% and + 23%) compared to TRT females (see ). An appropriate level of testosterone in postmenopausal women has protective effects against depressed mood, decreased muscle mass, reduced bone density, and decreased sense of well-being (). No correlations were found between basal free testosterone level or testosterone/cortisol ratio and strength gains, unlike other data from Hakkinen () who showed that the individual basal testosterone/cortisol ratios correlated with 1RM increases in response to RT. Our data failed to find such correlations in all tested exercises. Our study has some limitations: the first is the lack of biochemical measurements at 4th month (before the split of the groups); however, considering that our aim was to investigate the effects of HIIRT vs TRT and not the simple effect of a traditional training period, blood parameters were evaluated at the end of the study. The second is the use of BIA which, although a widely used and reliable methods for this kind of investigation, is not the gold standard for body composition analysis. Thus, long term physiological and anthropometric changes during HIIRT protocol warrant further investigation.

5. Conclusions

Our data suggest that high intensity interval resistance training (HIIRT) can be safely performed by older individuals. No differences were detected in strength performance, whilst HIIRT produced slightly better body composition changes these results should be interpreted with care considering the methodology used by maintaining fat free mass and preventing fat mass gain. Moreover, HIIRT significantly reduced basal insulin levels, suggesting an effect on insulin sensitivity. The reduction of total cholesterol and LDL, together with the significant increase of IGFBP1, observed in the HIIRT groups suggest a direct relationship between the intensity of RT and improvement of blood lipids parameters and associated cardiovascular risks. HIIRT could be implemented as an efficient training method to improve blood lipids and other cardiovascular risk factors.

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