It has been clearly established that maximal force and power is lower in the morning compared to noon or afternoon hours. This morning neuromuscular deficit can be diminished by regularly training in the morning hours. However, there is limited and contradictory information upon hypertrophic adaptations to time-of-day-specific resistance training. Moreover, no cellular or molecular mechanisms related to muscle hypertrophy adaptation have been studied with this respect. Therefore, the present study examined effects of the time-of-day-specific resistance training on muscle hypertrophy, phosphorylation of selected proteins, hormonal concentrations and neuromuscular performance. Twenty five previously untrained males were randomly divided into a morning group (n = 11, age 23 ± 2 yrs), afternoon group (n = 7, 24 ± 4 yrs) and control group (n = 7, 24 ± 3 yrs). Both the morning and afternoon group underwent hypertrophy-type of resistance training with 22 training sessions over an 11-week period performed between 07:30-08:30 h and 16:00-17:00 h, respectively. Isometric MVC was tested before and immediately after an acute loading exclusively during their training times before and after the training period. Before acute loadings, resting blood samples were drawn and analysed for plasma testosterone and cortisol. At each testing occasion, muscle biopsies from m. vastus lateralis were obtained before and 60 min after the acute loading. Muscle specimens were analysed for muscle fibre cross-sectional areas (CSA) and for phosphorylated p70S6K, rpS6, p38MAPK, Erk1/2, and eEF2. In addition, the right quadriceps femoris was scanned with MRI before and after the training period. The control group underwent the same testing, except for MRI, between 11:00 h and 13:00 h but did not train. Voluntary muscle strength increased significantly in both the morning and afternoon training group by 16.9% and 15.2 %, respectively. Also muscle hypertrophy occurred by 8.8% and 11.9% (MRI, p < 0.001) and at muscle fibre CSA level by 21% and 18% (p < 0.01) in the morning and afternoon group, respectively. No significant changes were found in controls within these parameters. Both pre- and post-training acute loadings induced a significant (p < 0.001) reduction in muscle strength in all groups, not affected by time of day or training. The post-loading phosphorylation of p70S6Thr421/Ser424 increased independent of the time of day in the pre-training condition, whereas it was significantly increased in the morning group only after the training period (p < 0.05). Phosphorylation of rpS6 and p38MAPK increased acutely both before and after training in a time-of-day independent manner (p < 0.05 at all occasions). Phosphorylation of p70S6Thr389, eEF2 and Erk1/2 did not change at any time point. No statistically significant correlations were found between changes in muscle fibre CSA, MRI and cell signalling data. Resting testosterone was not statistically different among groups at any time point. Resting cortisol declined significantly from pre- to post-trai...

. (2013). Effects of time of day on resistance exerciseinduced anabolic signaling in skeletal muscle. Biological rhythm research, 44, s. 756-770. Dette er siste tekst-versjon av artikkelen, og den kan inneholde små forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på www.tandfonline.com: http://dx.doi.org/10. 1080/09291016.2012.740314 This is the final text version of the article, and it may contain minor differences from the journal's pdf version. The original publication is available at www.tandfonline.com: http://dx.doi.org/10. 1080/09291016.2012.740314 Effects of time of day on resistance exercise-induced anabolic signalling in skeletal muscle IntroductionTime of day has been shown to affect various indices related to neuromuscular performance in both acute responses to a bout of resistance exercise and long-term adaptations to resistance training. For instance, muscle strength is typically lower in the morning compared to the afternoon (for a review see (10)). However, lower neuromuscular performance in the morning can be improved to the afternoon levels by regularly training in the morning hours over the period of several weeks (34,35).Whether the hypertrophic adaptation of skeletal muscle to resistance training also is affected by the time-of-day-specific training, is less studied. To our best knowledge, the only study performed on humans found a tendency to smaller gains in muscle size when repeatedly training in the morning compared to the late afternoon hours (36). Although statistically insignificant, subjects training in the afternoon hours increased their m.quadriceps femoris volume, measured by magnetic resonance imaging, on average 30% more compared to their counterparts in the morning training group (36). One of the possible mechanisms contributing to the above-mentioned time-of-day-dependent training adaptations is signalling pathways involved in the control of protein synthesis and protein degradation.In general, muscle hypertrophy/atrophy is a net result of an increase in protein synthesis minus protein degradation. A single bout of resistance exercise is a potent stimulus for increasing the post-exercise rate of protein synthesis per se, both in the acute recovery phase and lasting up to 48 hours (24,29). Phosphorylation of specific proteins in protein kinase B/muscle target of rapamycin/p70 ribosomal S6 kinase signalling pathway (Akt/mTOR/p70S6K) and to some extent also in mitogen-activated protein kinases (MAPK) signalling pathway has been shown to positively regulate muscle growth (2,37,40). Further, resistance exercise primarily aimed at increasing muscle hypertrophy is a potent stimulus to increase mTOR and MAPK signalling (9,18,19,40). At least signalling through rapamycin sensitive mTOR complex 1 (mTORC1) is needed to induce protein synthesis after resistance exercise (9). However, there are very limited data available addressing whether and how the activation of these signalling pathways can be influenced by a single bout of exercise or repeated resistan...

Cluster sets allow for velocity and power output maintenance, but the literature routinely uses highly fatiguing traditional set protocols. Although such studies have merit, others suggest fatigue should be avoided when training to improve power output, making those cluster set studies less practical. Therefore, the purpose of this study was to compare these set structures when truncating sets using a power-based threshold. Nine males (23.4 ± 0.6 yr) with various sport backgrounds performed 6 sets of back squats with individualized loads that elicited the greatest mean power (MPmax) output (112.7 ± 12.1% of body mass). Each set during the traditional set (TS) protocol included as many repetitions as possible until two consecutive repetitions dropped below 90% MPmax, which was followed by 120 s inter-set rest. The design was identical for cluster sets (CS) but with an additional 20 s intra-set rest after every 2 repetitions. The number of repetitions performed, mean velocity, and mean power output, were analyzed using 2(protocol)*6(set) repeated measures ANOVA. The number of repetitions during CS (51.8 ± 14.4) was greater than TS (31.9 ± 3.7) (p = 0.001), but the average velocity (CS = 0.711 ± 0.069, TS = 0.716 ± 0.081 m·s-1; p = 0.732) and power output (CS = 630.3 ± 59.8, TS = 636.0 ± 84.3 W; p = 0.629) of those repetitions were similar. These data indicate that CS are a viable option for increasing training volume during contemporary training where sets are ended when repetitions drop below velocity or power thresholds.

The study compared the effect of 12-week multimodal training programme performed twice a week at the regular exercise facility (REF) with the 12-week multimodal training programme performed three times per week as a part of the research programme (EX). Additionally, the study analysed how the experimental training programme affect the physical performance of cognitive healthy and mild cognitive impaired elderly (MCI). The REF training group included 19 elderly (65.00±3.62 years). The experimental training programme combined cognitively healthy (EXH: n=16; 66.3±6.42 years) and age-matched individuals with MCI (EXMCI: n=14; 66.00±4.79 years). 10m maximal walking speed (10mMWS), Five Times Sit-to-Stand Test (FTSS), maximal and relative voluntary contraction (MVC & rel. MVC) were analysed. The REF group improved in 10mMWS (t=2.431, p=.026), the MVC (t=-3.528, p=.002) and relative MVC (t=3.553, p=.002). The EXH group improved in FTSS (t=5.210, P=.000), MVC (t=2.771, p=.018) and relative MVC (t=-3.793, p=.004). EXMCI improved in FTSS (t=2.936, p=.012) and MVC (t=-2.276, p=.040). According to results, both training programmes sufficiently improved walking speed and muscle strength in cognitively healthy elderly. Moreover, the experimental training programme improved muscle strength in MCI elderly.

IntroductionAndrogen deficiency of the ageing male is a clinical syndrome resulting from the low production of androgens (testosterone levels <6.9 nmol/L) with symptoms including decline in lean mass, muscle strength, increases in body mass and overall fat mass. The aim of the study is to examine the effect of a 12 week strength training intervention on body composition, physical function, muscle cellular and molecular and selected biochemical markers of metabolic health in hypogonadal patients.Methods and analysisThe study is three-group controlled 12-week experiment to assess the effect of strength training on hypogonadal patients with testosterone replacement therapy and newly diagnosed males without testosterone replacement therapy. Age matched healthy eugonadal males are also engaged in strength training. Lean mass is used to determine sample size indicating, that 22 subjects per group will be sufficient to detect intervention related changes at the power of 0.90. All outcomes are collected before the intervention (pre-intervention assessments) and after the intervention (post-intervention assessments). Clinical outcomes are body composition (lean mass, fat mass and total body mass) measured by dual-energy X-ray absorptiometry, physical functioning assessed by physical tests and psychosocial functioning. The most important haematological and biochemical parameters included are glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, testosterone, luteinizing hormone, follicle-stimulating hormone, sexhormone-binding globulin, insulin and prostate-specific antigen. Muscle cellular and molecular outcomes are muscle fibre size and regulators of muscle fibre size. Muscle cellular outcomes are measured from muscle biopsies obtained from musculus vastus lateralis.Ethics and disseminationThis trial is approved by Ethics Committee of the University Hospital in Bratislava, Slovakia, (ref. trial number: 127/2017) and all subjects will be fully informed on the rationale, risks and benefits of the study and sign the written informed consent prior to entering the study. Results will be published in peer-reviewed journals and presented in scientific conferences.Trial registration numberNCT03282682

The purpose of this study was to determine the changes in the resting level of serum cortisol, testosterone and T/C ratio in response to different training modalities and their variations. A secondary purpose was to identify if the various six weeks training programs are an effective way to improve physical fitness. 86 regularly active young males were assigned to one of six groups: Endurance constant running (ECR), Endurance interval running (EIR), Resistance training (RT), Explosive training (ET), Speed-endurance 50 m running (SER50) and Speed-endurance 150 m running (SER150) training. The resting levels of testosterone, cortisol and T/C ratio, as well as physical fitness, were measured. The ECR, EIR, and RT training program decreased COR level (P < 0.05). An increase of the T/C ratio was observed in the ECR and EIR group (P < 0.05). Except for SER50, each training program improved physical fitness. Our results suggest that endurance and resistance training modalities performed with a moderate to vigorous intensity may be a usable way to manage the resting cortisol level and enhance physical fitness in active young males.

Introduction:The objective of the study was to examine the relationship between the values of selected parameters of physical function, body composition, body mass index (BMI) and biochemical markers of metabolic health with the total testosterone (TT) levels in adult males. We aimed to analyse the correlation between these values and variations in the TT levels. Methods: A total of 17 subjects (age = 50.2 ± 8.1 years, TT = 11.4 ± 3.8 nmol/l) were included in the study. Subjects were tested on physical function (1RM on leg press, bench-press, handgrip, VO 2max ), body composition (DXA), biochemical parameters (morning fasting blood samples). Results: TT was inversely correlated with abdominal circumference (AC) (p < 0.01) and with overall body fat, measured in kg (p < 0.01). On a biochemical level, significant correlations were found between TT and insulin (p < 0.01), and TT and homeostasis model assessment of insulin resistance (HOMA-IR) (p < 0.01). Physical function, muscle strength or lean mass were not significantly correlated with TT. Conclusion: The main finding of this study was that testosterone levels had a strong inverse correlation with abdominal circumference and total body fat mass. On metabolic level, strong inverse correlation was also found between TT with insulin and TT with HOMA-IR. However, we did not find statistically significant correlation between total testosterone levels and lean mass, muscle strength or physical function in middle aged males.

Summary Proper mastering of a training means seems to be an important determinant of the quality of strength training. Aim of the paper is to examine the differences in strength in relation to squat-performing experience and to offer a way of improving performance by means of increasing the quality of squat technique. Methods 1. Subjects were divided into two groups according to their previous experience with performing squat: a group of inexperienced (n = 9; age: 21.1 years ± 2.37; height: 179.2 cm ± 8.18; weight: 70.0 kg ± 7.38) and experienced (n = 9; age: 24.0 years ± 1.07; height: 182.1 cm ± 4.14; weight: 81.2 kg ± 4.29). We carried out a test of maximal isometric strength in deep squat (ISOmax50°) and a modified diagnostic set (Fitro Force Plate) which consisted of repetitions of heel raised deep squats with a gradually increasing external loading (FmaxBW+(0-100%)). Posture and the body segments of the participants were not corrected during these tests. Mann-Whitney U test (α=0.05) was used to evaluate the data obtained. Results 1. After comparing the differences in the maximal value of force curve in dynamic muscular mode (FmaxBW+(0-100%)) and the maximal isometric force in deep squat (ISOmax50°) between the groups we found significantly bigger differences in the group of experienced when the resistance represented +75 % (Δ 279.0 N) and +100 % of body weight (Δ 332.2 N). Methods 2. Eleven inexperienced subjects (age: 22.1 years ± 1.52; weight: 78.2 kg ± 2.84) completed a short term experiment (with 4 training sessions in weeklong microcycle). The purpose was to practise deep squat without any content of targeted strength development. No control group was included. Initial and final measurements included the rate of force development test (RFD50°,90°,140°, 0-200 ms), the maximal isometric strength test (ISOmax50°,90°,140°) and the diagnostic set for deep squat (Fitro Dyne Premium). Wilcoxon T-test was used for further analyses (α = 0.01; α = 0.05). Results 2. We found statistically significant increments of ISOmax50° (Δ 89.45 N, p < 0.01), ISOmax90° (Δ 45.63 N, p < 0.05), RFD50°(0-200ms) (Δ 0.42 N.ms-1, p < 0.05), RFD90°(0-200ms) (Δ 0.47 N.ms-1, p < 0.05) and mean power output (Pmean) of entire diagnostic set (Δ 38.8 W, p < 0.01). Conclusions. Increases in the difference in variations between the groups starting from the resistance of 50 % of body weight confirms the recommendations of using lower weights for beginners for the purpose of strength development. Based on the results we conclude that a short-term training programme of deep squat practise (without any intention of improving strength performance) has positive effect on selected strength parameters.