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The physiological effects of low energy availability (EA) have been studied using a homogenous daily EA pattern in laboratory settings. However, whether this daily EA pattern represents those of free-living athletes and is therefore ecologically valid is unknown. To investigate this, we assessed daily exercise energy expenditure, energy intake and EA in 10 free-living elite male road cyclists (20 min Mean Maximal Power: 5.27 ± 0.25 W · kg−1) during 7 consecutive days of late pre-season training. Energy intake was measured using the remote-food photography method and exercise energy expenditure estimated from cycling crank-based power-metres. Seven-day mean ± SD energy intake and exercise energy expenditure was 57.9 ± 10.4 and 38.4 ± 8.6 kcal · kg FFM−1 · day−1, respectively. EA was 19.5 ± 9.1 kcal · kg FFM−1 · day−1. Within-participants correlation between daily energy intake and exercise energy expenditure was .62 (95% CI: .43 – .75; P < .001), and .60 (95% CI: .41 – .74; P < .001) between carbohydrate intake and exercise energy expenditure. However, energy intake only partially compensated for exercise energy expenditure, increasing 210 kcal · day−1 per 1000 kcal · day−1 increase in expenditure. EA patterns displayed marked day-to-day fluctuation (range: −22 to 76 kcal · kg FFM−1 · day−1). The validity of research using homogenous low EA patterns therefore requires further investigation.

We examined the effects of carbohydrate (CHO) feeding on lipid droplet (LD) morphology, muscle glycogen utilisation and exercise‐induced skeletal muscle cell signalling. After a 36 h CHO loading protocol and pre‐exercise meal (12 and 2 g kg–1, respectively), eight trained males ingested 0, 45 or 90 g CHO h–1 during 180 min cycling at lactate threshold followed by an exercise capacity test (150% lactate threshold). Muscle biopsies were obtained pre‐ and post‐completion of submaximal exercise. Exercise decreased (P < 0.01) glycogen concentration to comparable levels (∼700 to 250 mmol kg–1 DW), though utilisation was greater in type I (∼40%) versus type II fibres (∼10%) (P < 0.01). LD content decreased in type I (∼50%) and type IIa fibres (∼30%) (P < 0.01), with greater utilisation in type I fibres (P < 0.01). CHO feeding did not affect glycogen or IMTG utilisation in type I or II fibres (all P > 0.05). Exercise decreased LD number within central and peripheral regions of both type I and IIa fibres, though reduced LD size was exclusive to type I fibres. Exercise induced (all P < 0.05) comparable AMPKThr172 (∼4‐fold), p53Ser15 (∼2‐fold) and CaMKIIThr268 phosphorylation (∼2‐fold) with no effects of CHO feeding (all P > 0.05). CHO increased exercise capacity where 90 g h–1 (233 ± 133 s) > 45 g h–1 (156 ± 66 s; P = 0.06) > 0 g h–1 (108 ± 54 s; P = 0.03). In conditions of high pre‐exercise CHO availability, we conclude CHO feeding does not influence exercise‐induced changes in LD morphology, glycogen utilisation or cell signalling pathways with regulatory roles in mitochondrial biogenesis.

NEW FINDINGS: What is the central question of this study? What is the absolute level of pre-exercise glycogen concentration required to augment the exercise-induced signalling response regulating mitochondrial biogenesis? What is the main finding and its importance? Commencing high-intensity endurance exercise with reduced pre-exercise muscle glycogen concentrations confers no additional benefit to the early signalling responses that regulate mitochondrial biogenesis. ABSTRACT: We examined the effects of graded muscle glycogen on the subcellular location and protein content of AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and mRNA expression of genes associated with the regulation of mitochondrial biogenesis and substrate utilisation in human skeletal muscle. In a repeated measures design, eight trained male cyclists completed acute high-intensity interval (HIT) cycling (8 × 5 min at 80% peak power output) with graded concentrations of pre-exercise muscle glycogen. Following initial glycogen-depleting exercise, subjects ingested 2 g kg-1 (L-CHO), 6 g kg-1 (M-CHO) or 14 g kg-1 (H-CHO) of carbohydrate during a 36 h period, such that exercise was commenced with graded (P

Purpose Due to its eccentric nature, downhill running (DR) training has been suggested to promote strength gains through neuromuscular adaptations. However, it is unknown whether short-term chronic DR can elicit such adaptations. Methods Twelve untrained, young, healthy adults (5 women, 7 men) took part in 4 weeks’ DR, comprising 10 sessions, with running speed equivalent to 60–65% maximal oxygen uptake ($$\dot{V}$$ V ˙ O2max, assessed at weeks 0 and 4). Isometric and isokinetic knee-extensor maximal voluntary torque (MVT), vastus lateralis (VL) muscle morphology/architecture (anatomical cross-sectional area, ACSA; physiological CSA, PCSA; volume; fascicle length, Lf; pennation angle, PA) and neuromuscular activation (VL EMG) were assessed at weeks 0, 2 and 4. Results MVT increased by 9.7–15.2% after 4 weeks (p p r = 0.86, p = 0.001). VL ACSA (+2.9 ± 2.7% and +7.1 ± 3.5%) and volume (+2.5 ± 2.5% and +6.6 ± 3.2%) increased after 2 and 4 weeks, respectively (p Lf (+2.7 ± 2.2%) increased after 4 weeks (p r = 0.67, p = 0.03) and PCSA (r = 0.71, p = 0.01) correlated with changes in concentric MVT from 2 to 4 weeks. $$\dot{V}$$ V ˙ O2max (49.4 ± 6.2 vs. 49.7 ± 6.3 mL·kg−1·min−1) did not change after 4 weeks (p = 0.73). Conclusion Just 4 weeks’ moderate-intensity DR promoted neuromuscular adaptations in young, healthy adults, typically observed after high-intensity eccentric resistance training. Neural adaptations appeared to contribute to most of the strength gains at 2 and 4 weeks, while muscle hypertrophy seemed to contribute to MVT changes from 2 to 4 weeks only.

Background “Sleep Low-Train Low” is a training-nutrition strategy intended to purposefully reduce muscle glycogen availability around specific exercise sessions, potentially amplifying the training stimulus via augmented cell signalling. The aim of this study was to assess the feasibility of a 3-week home-based “sleep low-train low” programme and its effects on cycling performance in trained athletes. Methods Fifty-five trained athletes (Functional Threshold Power [FTP]: 258 ± 52W) completed a home-based cycling training program consisting of evening high-intensity training (6 × 5 min at 105% FTP), followed by low-intensity training (1 hr at 75% FTP) the next morning, three times weekly for three consecutive weeks. Participant’s daily carbohydrate (CHO) intake (6 g·kg-1·d-1) was matched but timed differently to manipulate CHO availability around exercise: no CHO consumption post- HIT until post-LIT sessions [Sleep Low (SL), n = 28] or CHO consumption evenly distributed throughout the day [Control (CON), n = 27]. Sessions were monitored remotely via power data uploaded to an online training platform, with performance tests conducted pre-, post-intervention. Results LIT exercise intensity reduced by 3% across week 1, 3 and 2% in week 2 (P < 0.01) with elevated RPE in SL vs. CON (P < 0.01). SL enhanced FTP by +5.5% vs. +1.2% in CON (P < 0.01). Comparable increases in 5-min peak power output (PPO) were observed between groups (P < 0.01) with +2.3% and +2.7% in SL and CON, respectively (P = 0.77). SL 1-min PPO was unchanged (+0.8%) whilst CON improved by +3.9% (P = 0.0144). Conclusion Despite reduced relative training intensity, our data demonstrate short-term “sleep low-train low” intervention improves FTP compared with typically “normal” CHO availability during exercise. Importantly, training was completed unsupervised at home (during the COVID-19 pandemic), thus demonstrating the feasibility of completing a “sleep low-train low” protocol under non-laboratory conditions.

Infographic 1: UEFA 2020 expert group statement in elite football: Training day. Infographic 2: UEFA 2020 expert group statement in elite football: match-day. Infographic 3: UEFA 2020 expert group statement in elite football: Best of the rest—8 other key take-home messages. UEFA commissioned an expert group statement on nutrition in elite football.1 Gathering 32 global experts in football and nutrition research …

Purpose: (1) To compare the sleep of female players from a professional soccer team to nonathlete controls across an in-season week and (2) to compare the sleep of core and fringe players from the same team on the night after a match to training nights. Methods: Using an observational design, 18 professional female soccer players and 18 female nonathlete controls were monitored for their sleep via wristwatch actigraphy across 1 week. Independent-sample t tests and Mann–Whitney U tests were performed to compare sleep between groups, while an analysis of variance compared sleep on training nights to the night after a match. Results: Soccer players had significantly greater sleep duration than nonathlete controls (+38 min; P = .009; d: 0.92), which may have resulted from an earlier bedtime (−00:31 h:min; P = .047; d: 0.70). The soccer players also had less intraindividual variation in bedtime than nonathletes (−00:08 h:min; P = .023; r: .38). Despite this, sleep-onset latency was significantly longer among soccer players (+8 min; P = .032; d: 0.78). On the night after a match, sleep duration of core players was significantly lower than on training nights (−49 min; P = .010; d: 0.77). In fringe players, there was no significant difference between nights for any sleep characteristic. Conclusions: During the in-season period, sleep duration of professional female soccer players is greater than nonathlete controls. However, the night after a match challenges the sleep of players with more match involvement and warrants priority of sleep hygiene strategies.

The aim of this study was to examine the physiological profiles and the pacing strategies of the father (59 yr old) and son (34 yr old) who broke the World Record time (4:59:22; father: 2:27:52, son: 2:31:30) for combined father and son marathon in 2019. Oxygen uptake (V̇o2), heart rate (HR), ventilation (V̇e), blood lactate concentration (La), and running economy (RE) were measured during treadmill-running tests. The total distance of the marathon was divided into eight sections of 5 km and one last section of 2.195 km, and the relative average running velocity on each section was calculated individually. V̇o2max, HRmax, V̇emax, and Lamax were 65.4 mL·kg−1·min−1, 165 beats/min, 115 L/min, 5.7 mmol/L for the father and 66.9 mL·kg−1·min−1, 181 beats/min, 153 L/min, 11.5 mmol/L for the son, respectively. At 17 km/h, RE was 210 mL·kg−1·km−1 for the father and 200 mL·kg−1·km−1 for the son, and % V̇o2max sustained was 90.9% for the father and 84.5% for the son, respectively. The father maintained an even running velocity during the marathon (running velocity CV NEW & NOTEWORTHY We provide novel data demonstrating that different physiological profiles can lead to the same level of performance in a marathon, even at different ages. The novelty of our study is that we report on the physiological characteristics, training routine, and in-race pacing strategy that allowed a father (59 yr old) and son (34 yr old) to break the World Record time for combined father and son marathon. The father also established a new World record marathon time for the age of 59.

Deliberately training with reduced carbohydrate (CHO) availability to enhance endurance-training-induced metabolic adaptations of skeletal muscle (i.e. the 'train low, compete high' paradigm) is a hot topic within sport nutrition. Train-low studies involve periodically training (e.g., 30-50% of training sessions) with reduced CHO availability, where train-low models include twice per day training, fasted training, post-exercise CHO restriction and 'sleep low, train low'. When compared with high CHO availability, data suggest that augmented cell signalling (73% of 11 studies), gene expression (75% of 12 studies) and training-induced increases in oxidative enzyme activity/protein content (78% of 9 studies) associated with 'train low' are especially apparent when training sessions are commenced within a specific range of muscle glycogen concentrations. Nonetheless, such muscle adaptations do not always translate to improved exercise performance (e.g. 37 and 63% of 11 studies show improvements or no change, respectively). Herein, we present our rationale for the glycogen threshold hypothesis, a window of muscle glycogen concentrations that simultaneously permits completion of required training workloads and activation of the molecular machinery regulating training adaptations. We also present the 'fuel for the work required' paradigm (representative of an amalgamation of train-low models) whereby CHO availability is adjusted in accordance with the demands of the upcoming training session(s). In order to strategically implement train-low sessions, our challenge now is to quantify the glycogen cost of habitual training sessions (so as to inform the attainment of any potential threshold) and ensure absolute training intensity is not compromised, while also creating a metabolic milieu conducive to facilitating the endurance phenotype.

This study assessed the cardiorespiratory capacity and running economy (RE) of a 59-yr-old ex-Olympian athlete who ran a marathon in 2:30:15 in 2019. The athlete retired from running at 32 yr old (best marathon performance: 2:13:59) for a 16-yr period after his participation at the Olympics.Heart rate (HR), oxygen uptake (V˙O2), ventilation (VE), blood lactate concentration (La), step frequency, and RE were measured during a treadmill-running test.His HRmax, VEmax, Lamax, and V˙O2max were 165 bpm, 115 L·min, 5.7 mmol·L, and 65.4 mL·kg·min, respectively. At his marathon pace, his RE was 210 mL·kg·min with a step frequency of 199 ± 0.55 s·min, and his V˙O2 corresponded to 91% of his V˙O2max.This study shows that despite a 16-yr break in training, this 59-yr-old former Olympian marathoner has managed to limit the age-related decline in performance to ~5% per decade. More generally, these data suggest that high-level endurance masters athletes can limit the age-related decline in endurance performance at least until the age of 60 yr and can preserve their ability to sustain high-intensity effort (90% of V˙O2max) for long-duration (2-3 h) exercises.

We examined the effects of graded muscle glycogen on exercise capacity and modulation of skeletal muscle signaling pathways associated with the regulation of mitochondrial biogenesis. In a repeated-measures design, eight men completed a sleep-low, train-low model comprising an evening glycogen-depleting cycling protocol followed by an exhaustive exercise capacity test [8 × 3 min at 80% peak power output (PPO), followed by 1-min efforts at 80% PPO until exhaustion] the subsequent morning. After glycogen-depleting exercise, subjects ingested a total of 0 g/kg (L-CHO), 3.6 g/kg (M-CHO), or 7.6 g/kg (H-CHO) of carbohydrate (CHO) during a 6-h period before sleeping, such that exercise was commenced the next morning with graded ( P < 0.05) muscle glycogen concentrations (means ± SD: L-CHO: 88 ± 43, M-CHO: 185 ± 62, H-CHO: 278 ± 47 mmol/kg dry wt). Despite differences ( P < 0.05) in exercise capacity at 80% PPO between trials (L-CHO: 18 ± 7, M-CHO: 36 ± 3, H-CHO: 44 ± 9 min), exercise induced comparable AMPKThr172 phosphorylation (~4-fold) and PGC-1α mRNA expression (~5-fold) after exercise and 3 h after exercise, respectively. In contrast, neither exercise nor CHO availability affected the phosphorylation of p38MAPKThr180/Tyr182 or CaMKIIThr268 or mRNA expression of p53, Tfam, CPT-1, CD36, or PDK4. Data demonstrate that when exercise is commenced with muscle glycogen < 300 mmol/kg dry wt, further graded reductions of 100 mmol/kg dry weight impair exercise capacity but do not augment skeletal muscle cell signaling. NEW & NOTEWORTHY We provide novel data demonstrating that when exercise is commenced with muscle glycogen below 300 mmol/kg dry wt (as achieved with the sleep-low, train-low model) further graded reductions in preexercise muscle glycogen of 100 mmol/kg dry wt reduce exercise capacity at 80% peak power output by 20–50% but do not augment skeletal muscle cell signaling.

Background Thanks to the specific materials they embed, far infrared (FIR)-emitting garments can interact with the body’s physiological functions. Such effects have been sought in medicine and physiotherapy for a long time for the treatment/relief of a variety of pathologies and disabling conditions. Recently, FIR-emitting garments have been introduced in the sporting domain under the influence of manufacturers seeing here a new opportunity to support physical performance in athletes, though this is not clearly established. To fill this gap, in this systematic review, we summarize the scientific evidence on the use of FIR-emitting garments in sport and provide directions for future research by shedding light on current scientific limitations. Method Five scientific databases (PubMed, Cochrane, ScienceDirect, Scopus and SPORTDiscus) were searched by two independent reviewers. Studies investigating the effects of FIR-emitting garments on at least one physiological outcome related to exercise performance and/or recovery in humans were selected. The methodological quality of retained studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. Results and discussion Eleven studies met the inclusion criteria and were included in the systematic review. Studies investigating similar outcomes related to exercise performance or recovery were scarce and results inconclusive, which prevents from drawing firm conclusion about the utilisation of FIR-emitting garments in athletes. However, these early results show that FIR-emitting garments may be of interest for exercise performance and recovery, mainly through their effects on the body’s thermoregulation and haemodynamic function. The summary provided in this review can be used to inform the design of future studies. (PROSPERO registration number: CRD42021238029).

Purpose: We investigated the effect of a chronic dietary periodization strategy on endurance performance in trained athletes. Methods: 21 triathletes (V[Combining Dot Above]O2max: 58.7 +/- 5.7 mL[middle dot]min-1[middle dot]kg-1) were divided into 2 groups: a "sleep-low" (SL, n = 11) and a control group (CON, n = 10) consumed the same daily carbohydrate (CHO) intake (6 g[middle dot]kg-1[middle dot]d-1) but with different timing over the day to manipulate CHO availability before and after training sessions. The "sleep low" strategy consisted of a 3-week training/diet intervention comprising three blocks of diet/exercise manipulations: 1) "train-high" interval training sessions (HIT) in the evening with high-CHO availability; 2) overnight CHO restriction ("sleeping-low"), and 3) "train-low" sessions with low endogenous and exogenous CHO availability. The CON group followed the same training program but with high CHO availability throughout training sessions (no CHO restriction overnight, training sessions with exogenous CHO provision). Results: There was a significant improvement in delta efficiency during submaximal cycling for SL versus CON (CON: +1.4 +/- 9.3 %, SL: +11 +/- 15 %, P

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a ‘food first’ philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Basketball play is classically accompanied with a significant loss of body water with a potential negative impact on both physical and cognitive performance 1. Very few studies have examined the impact of dehydration on biomechanical adjustments required to score in basketball, though joints angles, the position of the centre of mass and ball release parameters (i.e. height, release speed and angle) are among the best predictive factors of success in basketball shooting 2. Dehydration might alter the biomechanical requirements of successful shots and especially three-point shots (3PS) which generate 16% of points scored during a match. However, only 35% of 3PS are successful in game. Within this framework we analysed the effects of a controlled dehydration protocol on the success and technique of 3PS in elite basketball players. Changes in shooting technique were analysed through changes in body kinematics (i.e. 3D angles of the ankle, knee, hip, shoulder, elbow and wrist, and the height of the centre of mass) and ball release parameters (i.e. height, velocity and angle of the ball at release) of 3PS in a dynamic playing condition.

International audience; Introduction : The study aimed to investigate how a distortion of perceived exertion in the heat may affect, during a self-paced cycling exercise preceded by prior cognitive task, the thermal perception and the subsequent regulation of power output in high level athletes.Methods : Eleven endurance trained male athletes completed four experimental sessions including a 30-min fixed-RPE (15-Hard) cycling exercise in neutral (TMP-22 °C) and hot (HOT-37 °C) conditions, following a 60-min incongruent Stroop task (EXP) or passively watching documentary films (CON). Central and peripheral performances of the knee extensors were assessed before the cognitive task and after the exercise.Results : Although mental demand and effort were higher in EXP (P

Elite athletes frequently undergo periods of intensified training (IT) within their normal training program. These periods can lead athletes into functional overreaching, characterized by high perceived fatigue, impaired sleep, and performance. Because whole-body cryostimulation (WBC) has been proven to be an effective recovery method in the short term (76 h), we investigated whether daily WBC sessions during IT could prevent exercise and sleep-related signs of overreaching.After a normal training week (BASE), 10 elite synchronized swimmers performed two 2-wk IT periods in a randomized crossover fashion using WBC daily (ITWBC) or not (ITCON), separated by 9 d of light training. Swim time trials (400 m) were performed at BASE and after each IT to quantify blood lactate ([La]B), HR (HR400), salivary alpha amylase ([α-amylase]s400), and cortisol ([cortisol]s400) responses. Swimmers wore a wrist actigraph nightly to monitor sleep patterns.Swim speed (400 m), [La]B400, and [α-amylase]s400 decreased from BASE to ITCON, although no significant changes were found after ITWBC. Decreased swim speed was correlated to decreased HR400 and [cortisol]s400. During ITCON, significant decreases in actual sleep duration (-21 ± 7 min) and sleep efficiency (-1.9% ± 0.8%) were observed, with increased sleep latency (+11 ± 5 min) and fatigue compared with BASE, although these variables did not change during ITWBC. Using a qualitative statistical analysis, we observed that daily WBC use resulted in a 98%, 59%, 66%, and 78% chance of preserving these respective variables compared with ITCON.WBC use during IT helped mitigate the signs of functional overreaching observed during ITCON, such as reduced sleep quantity, increased fatigue, and impaired exercise capacity. These results support the daily use of WBC by athletes seeking to avoid functional overreaching during key periods of competition preparation.

While effects of the two classes of proteins found in milk (i.e., soluble proteins, including whey, and casein) on muscle protein synthesis have been well investigated after a single bout of resistance exercise (RE), the combined effects of these two proteins on the muscle responses to resistance training (RT) have not yet been investigated. Therefore, the aim of this study was to examine the effects of protein supplementation varying by the ratio between milk soluble proteins (fast-digested protein) and casein (slow-digested protein) on the muscle to a 9-week RT program. In a double-blind protocol, 31 resistance-trained men, were assigned to 3 groups receiving a drink containing 20g of protein comprising either 100% of fast protein (FP(100), n = 10), 50% of fast and 50% of slow proteins (FP(50), n = 11) or 20% of fast protein and 80% of casein (FP(20), n = 10) at the end of training bouts. Body composition (DXA), and maximal strength in dynamic and isometric were analyzed before and after RT. Moreover, blood plasma aminoacidemia kinetic after RE was measured. The results showed a higher leucine bioavailability after ingestion of FP(100) and FP(50) drinks, when compared with FP(20) (p< .05). However, the RT-induced changes in lean body mass (p < .01), dynamic (p < .01), and isometric muscle strength (p < .05) increased similarly in all experimental groups. To conclude, compared with the FP(20) group, the higher rise in plasma amino acids following the ingestion of FP(100) and FP(50) did not lead to higher muscle long-term adaptations.

This study aimed to test the reproducibility of running performance, neuromuscular fatigue markers and indirect muscle damage indicators in a field-based trail time-trial.Running performance and changes in classical physiological parameters were analysed in 11 experienced trail runners before and in the days following four bouts of outdoor trail running (15.6 km), 7 days apart.Heart rate, running time and lactate concentration were monitored in each running bout. Maximal voluntary contraction torque, counter movement jump height, plasma creatine kinase activity and muscle soreness were assessed before and 1, 24 and 48 h post-race. Within-bout changes were elucidated using a two-way repeated measures ANOVA. Inter-repetition reproducibility was examined using an intraclass correlation coefficient (R) and the mean intra-subject coefficient of variation at each measurement time point.Running time was longer (p0.05) for the first bout compared with the other three bouts. Magnitude and time course of changes in counter movement jump height, creatine kinase activity and muscle soreness were similar among all four bouts (overall peak means: -17%, +35% and 54/100mm respectively). The acute reduction in maximal voluntary contraction torque (peak mean: -17%) was attenuated exclusively in the fourth bout (p0.05). The two middle bouts showed good reproducibility (intraclass correlation coefficient and coefficient of variation) for running time, maximal voluntary contraction torque and counter movement jump height, but low to moderate for creatine kinase activity, muscle soreness, blood lactate and rate of perceived exertion.A short outdoor trail run is a reliable model for investigations of fatigue and muscle damage, but certain methodological precautions should be respected.

Master athletes are more than 35 years of age and continue to train as hard as their young counterparts despite the aging process. All life long, they are capable of accomplishing exceptional sporting performances. For these participants in endurance events, matching energy intake and expenditure is critical to maintain health and performance. The proportions of carbohydrate, fat, and protein must be optimized to provide enough calories to sustain the energy requirements of competition or training, and for recovery. In addition, endurance athletes must include adequate vitamins and minerals in their diets to maintain healthy immune function. Vitamins and minerals may be sufficient in the diets of endurance athletes, who have a high energy intake. This would make it unnecessary to use vitamin and mineral supplements. Furthermore, one major limitation for these athletes is the management of oxidative stress, which, when in excess, can be deleterious for the organism. For individuals exposed to oxidative stress, micronutritional supplementations rich in vitamins and minerals can be also an alternative strategy. Although these supplementations are increasingly used by master athletes, very few data are available on their effects on oxidative stress, muscle recovery, and physical performance. The potential benefits of supplement use in athletes are thus questionable. Some studies indicate no benefits, while others highlight potential negative side effects of vitamin supplementation. Additional studies are warranted in order to design adapted prescriptions in antioxidant vitamins and minerals.

Muscle glycogen levels have a profound impact on an athlete’s sporting performance, thus measurement is vital. Carbohydrate manipulation is a fundamental component in an athlete’s lifestyle and is a critical part of elite performance, since it can provide necessary training adaptations. This paper provides a critical review of the current invasive and non-invasive methods for measuring skeletal muscle glycogen levels. These include, the gold standard muscle biopsy, histochemical analysis, magnetic resonance spectroscopy and musculoskeletal high frequency ultrasound, as well as pursuing future application of electromagnetic sensors in the pursue of portable non-invasive quantification of muscle glycogen. This paper will be of interest to researchers who wish to understand the current and most appropriate techniques in measuring skeletal muscle glycogen and to seek understanding in the need for development in equipment which can be used in, e.g., elite sporting competition and improve physiological training adaptations to carbohydrate manipulation.

The aim of the present study was to compare the maximal isometric torque and cardio-respiratory parameters in well-trained young and master triathletes prior to and following an Olympic distance triathlon. One day before and 24 h following the event, participants performed three maximum voluntary isometric knee extensions and flexions and an incremental running test on a treadmill to determine the maximal isometric torque, maximal oxygen uptake VO(2max), speed at VO(2max) (vVO(2)max), speed at ventilatory thresholds (VT1 and VT2) and submaximal running economy. Prior to the event VO(2max), vVO(2)max, speed at ventilatory thresholds and running economy were significantly lower in master athletes, but maximal voluntary torque was similar between the groups. 24 h following the race, a similar significant decrease in VO(2max) (-3.1% in masters, and -6.2% in young, p < 0.05), and vVO(2)max (-9.5% in masters, and -5.6% in young, p < 0.05) was observed in both the groups. The speed at VT2 significantly decreased only in master athletes (-8.3%, p < 0.05), while no change was recorded in maximal voluntary torque or submaximal running economy following the event. The results indicate that for well-trained subjects, the overall relative exercise intensity during an Olympic distance triathlon and the fatigue 24 h following the event seem to be independent of age.

International audience; The influence of vitamin and mineral complex supplementation on muscular activity and cycling efficiency was examined in elderly endurance-trained master athletes during a heavy cycling trial. Master athletes were randomly assigned in a double-blind process to 1 of 2 treatment groups: antioxidant supplementation (n = 8: As group) or placebo (n = 8: Pl group) for 21 days. After that time, each subject had to perform a 10-min session of cycling on a cycloergometer at a heavy constant intensity. Twenty-four to 48 h after this session, subjects performed an isometric maximal voluntary contraction before and immediately after a fatiguing strength training (leg press exercise) and the same 10-min cycling test after fatigue. Isometric maximal voluntary force (MVF) of knee extensors was assessed before and after fatigue. Electromyographic (EMG) activity of the vastus medialis, the vastus lateralis (VL), and the biceps femoris was recorded with surface EMG. The knee-extensors MVF after the fatiguing exercise was reduced in similar proportions for both groups (As, –10.9%; Pl, –11.3%, p < 0.05). This MVF loss was associated with a significant reduction in EMG frequency parameters for both groups, with a lower decrease for the As group. Muscular activity and cycling efficiency during the cycling bouts were affected by the treatment. Cycling efficiency decreased significantly and the oxygen uptake slow component was higher after the fatiguing exercise for both groups. Furthermore, a decrease in cycling efficiency was associated with an increase in VL activity. However, these changes were significantly lower for the As group. The results of the present study indicate an overall positive effect of vitamin and mineral complex supplementation on cycling efficiency after fatigue, in the endurance-trained elderly.; L'objet de cette étude était d'analyser l'influence d'une supplémentation en vitamines et minéraux sur la performance musculaire et le rendement au cours d'un exercice de cyclisme intense. Deux groupes de 8 personnes âgées régulièrement entrainées en endurance, ont été constitués selon une procédure en double aveugle avec l'apport soit d'un complexe d'antioxydants (n = 8 : groupe As), soit d'un placebo (n = 8 : groupe Pl) pendant 21 jours. Après 21 jours de supplémentation chaque sujet devait effectuer une session de cyclisme de 10 min à une intensité intense. 24 à 48 h après cette session les sujets réalisait un test d'évaluation de la force maximale volontaire (FMV) avant et après une séance d'entrainement en résistance et le même exercice de cyclisme après fatigue. La force maximale isométrique volontaire (FMV) des extenseurs du genou était testée avant et après fatigue. L'activité électromyographique (EMG) du vastus medialis (VM), vastus lateralis (VL) et biceps femoris (BF) était enregistrée à partir d'électrodes de surface. La FMV des muscles extenseurs du genou était réduite après l'exercice fatigant, dans des proportions similaires pour les 2 groupes (As, –10,9%; Pl, –11,3%, p < 0,05). Cette baisse de la FMV était accompagnée d'une réduction des paramètres EMG fréquentiels, pour les 2 groupes, avec toutefois une moindre diminution pour le groupe As. La tolérance à l'exercice en cyclisme était modifiée entre les 2 sessions. Le rendement en cyclisme était réduit et la composante lente de consommation d'oxygène était augmentée pour les 2 groupes après l'exercice fatigant. Cette altération du rendement en cyclisme était accompagnée d'une augmentation de l'activité musculaire du VL. Néanmoins ces changements étaient significativement moindres pour le groupe As. Les résultats de cette étude suggèrent un effet bénéfique d'une supplémentation en vitamines et minéraux sur le rendement en cyclisme après fatigue, chez des personnes âgées entraînées en endurance. Mots-clés : vieillissement, électromyographie, rendement en cyclisme, force maximale volontaire, athlète master.

Background: Much attention has been focused on the need to design strategies to increase functional capacities in older populations. This has raised several questions regarding the ability of regular endurance training to preserve functional capacity with age. Objective: The purpose of this study was to examine the age-associated changes in neuromuscular function in endurance-trained men before and after a high-intensity, intermittent fatiguing task. Method: Twenty-six healthy endurance-trained male subjects: 16 older (59–79 years) and 10 young (20–34 years) men performed a high-intensity, intermittent fatiguing exercise corresponding to 10 sets of 10 repetitions on a horizontal leg press at 70% of the individual one-repetition maximum. Maximal voluntary contractions and evoked contractions of the knee extensor muscles were performed before and after the exercise. Results: Decreases in maximum voluntary contractions (older: –9.7%; young: –14.3%) and electromyographic activity were not different between groups. Peak twitch torque was reduced only for the older men and no changes in voluntary activation and M-wave properties were recorded in either group. Conclusion: The present study indicates that in endurance-trained men aged 59–79 years, muscle functional capacities are maintained despite losses in strength and contractile function related to the age.

© 2015 Aubry et al This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Purpose: The aim of the study was to investigate whether heart rate recovery (HRR) may represent an effective marker of functional overreaching (f-OR) in endurance athletes. Methods and Results: Thirty-one experienced male triathletes were tested (10 control and 21 overload subjects) before (Pre), and immediately after an overload training period (Mid) and after a 2-week taper (Post). Physiological responses were assessed during an incremental cycling protocol to exhaustion, including heart rate, catecholamine release and blood lactate concentration. Ten participants from the overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% change in performance associated with concomitant high perceived fatigue). Additionally, only the f-OR group demonstrated a 99% chance of increase in HRR during the overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine (-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%, moderate). These blood measures returned to baseline levels at Post. HRR change was negatively correlated to changes in performance, peak HR and peak blood metabolites concentrations. Conclusion: These findings suggest that i) a faster HRR is not systematically associated with improved physical performance, ii) changes in HRR should be interpreted in the context of the specific training phase, the athletes perceived level of fatigue and the performance response; and, iii) the faster HRR associated with f-OR may be induced by a decreased central command and by a lower chemoreflex activity.

International audience; Recent research on whole-body cryotherapy has hypothesized a major responsibility of head cooling in the physiological changes classically reported after a cryostimulation session. The aim of this experiment was to verify this hypothesis by studying the influence of exposing the head to cold during whole-body cryostimulation sessions, on the thermal response and the autonomic nervous system (ANS). Over five consecutive days, two groups of 10 participants performed one whole-body cryostimulation session daily, in one of two different systems; one exposing the whole-body to cold (whole-body cryostimulation, WBC), and the other exposing the whole-body except the head (partial-body cryostimulation, PBC).10 participants constituted a control group (CON) not receiving any cryostimulation. In order to isolate the head-cooling effect on recorded variables, it was ensured that the WBC and PBC systems induced the same decrease in skin temperature for all body regions (mean decrease over the 5 exposures: -8.6°C±1.3°C and -8.3±0.7°C for WBC and PBC, respectively), which persisted up to 20-min after the sessions (P20). The WBC sessions caused an almost certain decrease in tympanic temperature from Pre to P20 (-0.28 ±0.11°C), while it only decreased at P20 (-0.14±0.05°C) after PBC sessions. Heart rate almost certainly decreased after PBC (-8.6%) and WBC (-12.3%) sessions. Resting vagal-related heart rate variability indices (the root-mean square difference of successive normal R-R intervals, RMSSD, and high frequency band, HF) were very likely to almost certainly increased after PBC (RMSSD:+49.1%, HF: +123.3%) and WBC (RMSSD: +38.8%, HF:+70.3%). Plasma norepinephrine concentration was likely increased in similar proportions after PBC and WBC, but only after the first session. Both cryostimulation techniques stimulated the ANS with a predominance of parasympathetic tone activation from the first to the fifth session and in slightly greater proportion with WBC than PBC. The main result of this study indicates that the head exposure to cold during whole-body cryostimulation may not be the main factor responsible for the effects of cryostimulation on the ANS.

Functional overreaching (F-OR) induced by heavy load endurance training programs has been associated with reduced heart rate values both at rest and during exercise. Because this phenomenon may reflect an impairment of cardiac response, this research was conducted to test this hypothesis. Thirty-five experienced male triathletes were tested (11 control and 24 overload subjects) before overloading (Pre), immediately after overloading (Mid), and after a 2-wk taper period (Post). Physiological responses were assessed during an incremental cycling protocol to volitional exhaustion, including catecholamines release, oxygen uptake (V̇o2), arteriovenous O2 difference, cardiac output (Q̇), and systolic (SBP) and diastolic blood pressure (DBP). Twelve subjects of the overload group developed signs of F-OR at Mid (decreased performance with concomitant high perceived fatigue), while 12 others did not [acute fatigue group (AF)]. V̇o2max was reduced only in F-OR subjects at Mid. Lower Q̇ and SBP values with greater arteriovenous O2 difference were reported in F-OR subjects at all exercising intensities, while no significant change was observed in the control and AF groups. A concomitant decrease in epinephrine excretion was reported only in the F-OR group. All values returned to baseline at Post. Following an overload endurance training program leading to F-OR, the cardiac response to exhaustive exercise is transiently impaired, possibly due to reduced epinephrine excretion. This finding is likely to explain the complex process of underperformance syndrome experienced by F-OR endurance athletes during heavy load programs.

International audience; Purpose: The purpose of this study is to examine whether performance supercompensation during taper is maximized in endurance athletes after experiencing overreaching during an overload training (OT) period. Methods: Thirty-three trained male triathletes were assigned to either OT (n = 23) or normal training groups (n = 10, CTL) during 8 wk. Cycling performance and maximal oxygen uptake (V ˙ O 2max) were measured after 1 wk of moderate training, a 3-wk period of OT, and then each week during 4-wk taper. Results: Eleven of the 23 subjects from the OT group were diagnosed as functionally overreached (FOR) after the overload period (decreased performance with concomitant high perceived fatigue), whereas the 12 other subjects were only acutely fatigued (AF) (no decrease in performance). According to qualitative statistical analysis, the AF group demonstrated a small to large greater peak performance supercompensation than the FOR group (2.6% T 1.1%) and the CTL group (2.6% T 1.6%). V ˙ O 2max increased significantly from baseline at peak performance only in the CTL and AF groups. Of the peak performances, 60%, 83%, and 73% occurred within the two first weeks of taper in CTL, AF, and OR, respectively. Ten cases of infection were reported during the study with higher prevalence in FOR (70%) than that in AF (20%) and CTL (10%). Conclusion: This study showed that 1) greater gains in performance and V ˙ O 2max can be achieved when higher training load is prescribed before the taper but not in the presence of FOR ; 2) peak performance is not delayed during taper when heavy training loads are completed immediately prior; and 3) FOR provides higher risk for training maladaptation, including increased infection risks. T he primary goal for coaches of high-performance athletes is to deliver a well-controlled training program to ensure that the maximal performance is achieved at major competitions. The best competition performances in endurance sports are often achieved after a taper phase, which is typically completed after periods of heavy training. The taper has been defined as a progressive, nonlinear reduction of the training load in the period before competition (19). The main purpose of the taper is to reduce physiological and psychological stressors of previous training and to remove residual fatigue so that sport performance can be optimized. Appropriate tapering is considered to be critical for maximizing athletic performance. However, at present, there is relatively little scientific information that can be used to guide coaches in prescribing appropriate tapering strategies for individual athletes, and as a result, many adopt a trial-and-error approach. Indeed, only recently has good empirical evidence been provided to allow us to understand the relations between the characteristics of endurance training during a taper and the associated endurance performance changes (2,16). For example, Bosquet et al. (3) used a meta-analytic analysis to describe the effects of alterations in the training characteristics during the taper on performance in competitive athletes. The results showed that the most efficient taper strategy for maximizing endurance performance gains was to perform a 2-wk taper with an exponential reduction in training volume by 41%–60% without any modification of either training intensity or frequency. Using mathematical modeling simulations, Thomas and Busso (21) demonstrated that the training leading into the taper may also influence the performance responses during taper (21). These stimulations predicted that a 20% increase in training beyond normal training load during 28 d before a taper would elicit larger performance gains compared with when habitual training load was maintained. This hypothesis was recently supported by Le Meur et al. (16), who compared performance supercompensation after a 1-wk taper in trained triathletes after 3 wk of training, which consisted of either overload or habitual training. At the end of the overload training (OT) period, a 9% decline in performance

PURPOSE: This study aimed to examine whether (i) objective markers of sleep quantity and quality are altered in endurance athletes experiencing overreaching in response to an overload training program and (ii) potential reduced sleep quality would be accompanied with a higher prevalence of upper respiratory tract infections in this population. METHODS: Twenty-seven trained male triathletes were randomly assigned to either overload (n = 18) or normal (CTL, n = 9) training groups. Respective training programs included a 1-wk moderate training phase followed by a 3-wk period of overload or normal training, respectively, and then a subsequent 2-wk taper. Maximal aerobic power and oxygen uptake (V̇O 2max) from incremental cycle ergometry were measured after each phase, whereas mood states and incidences of illness were determined from questionnaires. Sleep was monitored every night of the 6 wk using wristwatch actigraphy. RESULTS: Of the 18 overload training group subjects, 9 were diagnosed as functionally overreached (F-OR) after the overload period, as based on declines in performance and V̇O2max with concomitant high perceived fatigue (P < 0.05), whereas the other 9 overload subjects showed no decline in performance (AF, P > 0.05). There was a significant time-group interaction for sleep duration (SD), sleep efficiency (SE), and immobile time (IT). Only the F-OR group demonstrated a decrease in these three parameters (-7.9% ± 6.7%,-1.6% ± 0.7%, and-7.6% ± 6.6% for SD, SE, and IT, respectively, P < 0.05), which was reversed during the subsequent taper phase. Higher prevalence of upper respiratory tract infections were also reported in F-OR (67%, 22%, and 11% incidence rate for F-OR, AF, and CTL, respectively). CONCLUSION: This study confirms sleep disturbances and increased illness in endurance athletes who present with symptoms of F-OR during periods of high volume training. © 2014 by the American college of Sports Medicine.

International audience; The aim of this study was to compare the effects of a single whole-body cryostimulation (WBC) and a partial-body cryostimulation (PBC) (i.e., not exposing the head to cold) on indices of parasympathetic activity and blood catecholamines. Two groups of 15 participants were assigned either to a 3-min WBC or PBC session, while 10 participants constituted a control group (CON) not receiving any cryostimulation. Changes in thermal, physiological and subjective variables were recorded before and during the 20-min after each cryostimulation. According to a qualitative statistical analysis, an almost certain decrease in skin temperature was reported for all body regions immediately after the WBC (mean decrease±90% CL,-13.7±0.7°C) and PBC (-8.3±0.3°C), which persisted up to 20-min after the session. The tympanic temperature almost certainly decreased only after the WBC session (-0.32±0.04°C). Systolic and diastolic blood pressures were very likely increased after the WBC session, whereas these changes were trivial in the other groups. In addition, heart rate almost certainly decreased after PBC (-10.9%) and WBC (-15.2%) sessions, in a likely greater proportion for WBC compared to PBC. Resting vagal-related heart rate variability indices (the root-mean square difference of successive normal R-R intervals, RMSSD, and high frequency band, HF) were very likely increased after PBC (RMSSD: +54.4%, HF: +138%) and WBC (RMSSD: +85.2%, HF: +632%) sessions without any marked difference between groups. Plasma norepinephrine concentrations were likely to very likely increased after PBC (+57.4%) and WBC (+76.2%), respectively. Finally, cold and comfort sensations were almost certainly altered after WBC and PBC, sensation of discomfort being likely more pronounced after WBC than PBC. Both acute cryostimulation techniques effectively stimulated the autonomic nervous system (ANS), with a predominance of parasympathetic tone activation. The results of this study also suggest that a whole-body cold exposure induced a larger stimulation of the ANS compared to partial-body cold exposure.

International audience; The aim of the present study was to investigate the physiological demands of Supercross BMX during a simulated competition in elite athletes. During a preliminary session athletes underwent an incremental cycling test to determine maximal oxygen uptake (VO 2max) and power at ventilatory thresholds. In a second phase, athletes performed alone a simulated competition, consisting of six races separated by 30 minutes of passive recovery on an actual BMX track. During this simulated competition, oxygen uptake, blood lactate, anion gap and base excess (BE) were measured. Results indicated that a simulated BMX competition induces in elite athletes a high solicitation of both aerobic (mean peak VO 2 (VO 2peak): 94.3 ± 1.2 % VO 2max) and anaerobic glycolysis (mean blood lactate: 14.5 ± 4. 5 mmol.L-1) during every race. Furthermore, the repetition of six races separated by 30 min of recovery led to a significant impairment of the acid-base balance from the third to the sixth race (mean decrease in BE:-18.8 ± 7.5 %, p

OBJECTIVE: The aim of this study was to analyze the physiologic demand of pedaling on an electrically assisted bicycle to test its potential as an alternative method to perform exercise. DESIGN: Twenty participants (ten trained vs. ten untrained in endurance) novice in the electrically assisted bicycle performed the same cycling protocol composed of nine 5-min submaximal cycling periods without electrical support (NO), with a light support (S1), or with a high support (S4). The cycling conditions were tested at two different imposed speeds (16 and 21 km·hr) and one freely chosen speed (mean [SD], 18.1 [0.7] km·h). RESULTS: Mean power output, intensity, and energy expenditure were significantly lowered by the use of an electrical support, in similar proportions between the groups. For all subjects, the intensity of the electrically assisted bicycle in all measured conditions (S1 or S4) was sufficiently high to achieve the standards for moderate-intensity health-enhancing physical activity for adults (>3 metabolic equivalents). However, a vigorous intensity (>6 metabolic equivalents) was reached with the NO and S1 supports in the untrained group whatever the cycling speed and only at 21 km·hr with the light support (S1) in the endurance-trained group. CONCLUSIONS: By reducing the perceived sensation of effort while maintaining a sufficiently high energy expenditure, the electrically assisted bicycle has a great potential to promote physical activity in industrialized societies. Language: en

The analyses of ultraendurance athletes have provided new insights into the limits of human performance capacity and into medical complications when going beyond the physical limits. Ultradistance running poses a unique stress on the athlete. In their Viewpoint, Millet et al. (3) argued that determinants of performance in ultraendurance are subjected to a compromise between two main parameters: energy cost and lower limb tissue injury. The latter results from a complex combination of extrinsic factors (training errors including lack of specific strength, inappropriate footwear, inappropriate running surface, and terrain) and intrinsic factors (poor flexibility, biomechanical lower extremity malalignment, anthropometry, previous injury, running experience). Concerning the former, environmental conditions, training, and perhaps most importantly fluid and fuel intake all contribute to energy balance state and so race performance. In fact, nutrient intake during ultradistance races has been found to be below the estimated energy cost (1). Despite a low relative intensity the energy cost of running (expressed in mlO2) is increased during ultradistance trail running races (2) compared with level running. This induces a marked negative energy balance state that was shown to reduce serum leptin concentrations during ultramarathon race (5). Thus suboptimal nutrition certainly would result in decreased performance under these circumstances. Finally, it is proposed that the most important factor linking both parameters explaining ultramarathon tolerance is the eccentric load of long-term running causing an association between skeletal muscle damage and impaired renal function through dehydration, rhabdomyolysis, and hemolysis (4) further exacerbated without optimal nutrition intake. 3.484 JCR (2012) Q1, 7/84 Sport sciences; Q2, 20/80 Physiology UEM

International audience; The aim of this study was to examine the effects of cool water immersion (20°C; CWI), wearing a cooling jacket (‘Cryovest’;V) and a passive control (PAS) as recovery methods on physiological and thermoregulatory responses between two exercise bouts in temperate conditions. Nine well-trained male cyclists performed two successive bouts of 45min of endurance cycling exercise in a temperate environment (20°C) separated by 25min of the respective recovery interventions. Capillary blood samples were obtained to measure lactate (La-), Sodium(Na⁺), Bicarbonate (HCO₃ˉ) concentrations and pH, whilst body mass loss (BML), core temperature (Tcore), skin temperature (Tskin), heart rate (HR), oxygen uptake ( VO2 ) and minute ventilation ( VE ), were measured before (Pre), immediately after the first exercise bout (Ex1), the recovery (R) and after the second exercise bout (Ex2). V and CWI both resulted in a reduction of Tskin at R (-2.1±0.01°C and -11.6±0.01°C, respectively, P0.05), V attenuated the rise in HR, VE and VO2 from Ex1 to Ex2, while Tcore, and Tskin were significantly lower following the second session (P

The purpose of this study was to test the effect of a 3-week strength training program of knee extensor muscles on cycling delta efficiency in master endurance athletes. Nine master (age 51.5 ± 5.5 years) and 8 young (age 25.6 ± 5.9 years) endurance athletes with similar training levels participated in this study. During three consecutive weeks, all the subjects were engaged in a strength training program of the knee extensor muscles. Every week, they performed three training sessions consist of 10 × 10 knee extensions at 70% of maximal repetition with 3 min rest between in a leg extension apparatus. Maximal voluntary contraction torque (MVC torque) and force endurance (End) were assessed before, after every completed week of training, and after the program. Delta efficiency (DE) in cycling was evaluated before and after the training period. Before the training period, MVC torque, End, and DE in cycling were significantly lower in masters than in young. The strength training induced a significant improvement in MVC torque in all the subjects, more pronounced in masters (+17.8% in masters vs. +5.9% in young, P < 0.05). DE in cycling also significantly increased after training in masters, whereas it was only a trend in young. A significant correlation (r = 0.79, P < 0.01) was observed between MVC torque and DE in cycling in masters. The addition of a strength training program for the knee extensor muscles to endurance-only training induced a significant improvement in strength and cycling efficiency in master athletes. This enhancement in muscle performance alleviated all the age-related differences in strength and efficiency.

International audience; Enhanced recovery following physical activity and exercise-induced muscle damage (EIMD) has become a priority for athletes. Consequently, a number of post-exercise recovery strategies are used, often without scientific evidence of their benefits. Within this framework, the purpose of this study was to test the efficacy of whole body cryotherapy (WBC), far infrared (FIR) or passive (PAS) modalities in hastening muscular recovery within the 48 hours after a simulated trail running race. In 3 non-adjoining weeks, 9 well-trained runners performed 3 repetitions of a simulated trail run on a motorized treadmill, designed to induce muscle damage. Immediately (post), post 24 h, and post 48 h after exercise, all participants tested three different recovery modalities (WBC, FIR, PAS) in a random order over the three separate weeks. Markers of muscle damage (maximal isometric muscle strength, plasma creatine kinase [CK] activity and perceived sensations [i.e. pain, tiredness, well-being]) were recorded before, immediately after (post), post 1 h, post 24 h, and post 48 h after exercise. In all testing sessions, the simulated 48 min trail run induced a similar, significant amount of muscle damage. Maximal muscle strength and perceived sensations were recovered after the first WBC session (post 1 h), while recovery took 24 h with FIR, and was not attained through the PAS recovery modality. No differences in plasma CK activity were recorded between conditions. Three WBC sessions performed within the 48 hours after a damaging running exercise accelerate recovery from EIMD to a greater extent than FIR or PAS modalities.

International audience; To determine the acute effects of a trail running competition and the age-dependent differences between young and master athletes, 23 subjects [10 young (30.5 ± 7 years), 13 master (45.9 ± 5.9 years)] participated in a 55-km trail running competition. The study was conceived as an intervention study compromising pre, post 1, 24, 48 and 72 h measurements. Measurements consisted of blood tests, ergometer cycling and maximal isometric voluntary contractions (MVC). Parameters monitored included MVC, twitch-and M-wave properties, EMG (RMS) of the vastus lateralis, two locomotion efficiency calculations and muscle damage markers in the blood (CK, LDH). Results indicate post-race increases in CK and LDH, decreases in MVC values (-32 vs.-40% in young and master, P < 0.01), decreases in EMG, increases in contraction time and concomitant decreases in peak twitch values, and a decrease in locomotion efficiency (-4.6 vs.-6.3% in young and master, P < 0.05). Masters showed similar fatigue and muscle damage than young but recuperation was slowed in masters. This study shows that trail runs are detrimental to muscle function, and gives indication that training may not halt muscle deterioration through aging, but can help maintain performance level.

Knee extensor muscle strength and metabolism were examined in endurance trained young versus master athletes (10 elderly: 62.5+/-4.1 yr and 10 young: 26.2+/-2.4 yr). Before and immediately after a resistance strength training (RST), subjects performed a maximal isometric voluntary contraction (MVC) and a 10-min cycling test at a same relative intensity. During MVC, evoked contractions of the knee extensors muscles were performed to assess neuromuscular properties. Metabolism was assessed using oxygen uptake kinetics model. Before the RST session master athletes showed lower knee extensors MVC values than young subjects (257 vs. 354 N p0.05) without any difference in oxygen kinetics (respectively for elderly and young: oxygen slow component (VO2(sc)): 231 vs. 214 ml . min(-1) and time constant (tau1): 27.8 vs. 25.1 s, p0.05). After the RST session, a similar effect of fatigue was observed on muscular properties and oxygen kinetics whatever the group (respectively for elderly and young: MVC: -13.4 vs. -15.9%; VO2(sc): +11.8 vs.+25.2% and tau1: -15.4 vs. -13.9%). Our results suggest that the ability of master athletes to perform exercise at a given intensity is maintained despite a significant loss in strength with ageing.

International audience; The objectives of the present investigation was to analyze the effect of two different recovery modalities on classical markers of exercise-induced muscle damage (EIMD) and inflammation obtained after a simulated trail running race. Endurance trained males (n = 11) completed two experimental trials separated by 1 month in a randomized crossover design; one trial involved passive recovery (PAS), the other a specific whole body cryotherapy (WBC) for 96 h post-exercise (repeated each day). For each trial, subjects performed a 48 min running treadmill exercise followed by PAS or WBC. The Interleukin (IL)-1 (IL-1), IL-6, IL-10, tumor necrosis factor alpha (TNF-a), protein C-reactive (CRP) and white blood cells count were measured at rest, immediately post-exercise, and at 24, 48, 72, 96 h in post-exercise recovery. A significant time effect was observed to characterize an inflammatory state (Pre vs. Post) following the exercise bout in all conditions (p,0.05). Indeed, IL-1b (Post 1 h) and CRP (Post 24 h) levels decreased and IL-1ra (Post 1 h) increased following WBC when compared to PAS. In WBC condition (p,0.05), TNF-a, IL-10 and IL-6 remain unchanged compared to PAS condition. Overall, the results indicated that the WBC was effective in reducing the inflammatory process. These results may be explained by vasoconstriction at muscular level, and both the decrease in cytokines activity pro-inflammatory, and increase in cytokines anti-inflammatory.

PURPOSE: We investigated the effects of a 3-week dietary periodization on immunity and sleep in triathletes. METHODS: 21 triathletes were divided into two groups with different nutritional guidelines during a 3-week endurance training program including nine twice a day sessions with lowered (SL group) or maintained (CON group) glycogen availability during the overnight recovery period. In addition to performance tests, sleep was monitored every night. Systemic and mucosal immune parameters as well as the incidence of URTI were monitored every week of the training/nutrition protocol. Two-ways ANOVA and effect sizes were used to examine differences in dependent variables between groups at each time point. RESULTS: The SL group significantly improved 10 km running performance (-1 min 13 s, P

KEY POINTS: Reduced carbohydrate (CHO) availability before and after exercise may augment endurance training-induced adaptations of human skeletal muscle, as mediated via modulation of cell signalling pathways. However, it is not known whether such responses are mediated by CHO restriction, energy restriction or a combination of both. In recovery from a twice per day training protocol where muscle glycogen concentration is maintained within 200-350 mmol.kg-1 dw, we demonstrate acute post-exercise CHO and energy restriction (i.e.

Purpose A predominance of parasympathetic drive is observed following cold exposure. Such modulation of the autonomic nervous system (ANS) is associated with faster post-exercise recovery. Within this context, whole-body cryotherapy (WBC) has been spreading in sport medicine, though the optimal temperature and frequency are unclear. The aim of this study was to examine the effects of different cryotherapy conditions on the sympathovagal balance. Methods Forty healthy males were randomly assigned into five different groups (− 110 °C, − 60 °C, − 10 °C, control temperature [≃ 24 °C]) and undertook 5 WBC sessions over 5 consecutive days. Cardiac autonomic activity was assessed through heart rate variability (HRV) using power density of high frequency (HF), root-mean square difference of successive R–R intervals (RMSSD) and sympathovagal balance (LF/HF). Systemic sympathetic activity was assessed via circulating blood catecholamines. Results Mean weekly RMSSD (pre: 48 ± 22 ms, post: 68 ± 29 ms) and HF (pre: 607 ± 692 ms2, post: 1271 ± 1180 ms2) increased (p −1, p −1, p = 0.15). Conclusion These results suggest that one − 110 °C WBC exposure is required to stimulate the ANS. After five daily exposures, a lower autonomic response was recorded compared to day one, therefore suggesting the development of physiological habituation to WBC.

Purpose To investigate the effect of early evening exercise training at different intensities on nocturnal sleep and cardiac autonomic activity in endurance-trained runners. Methods Eight runners completed three experimental trials in a randomised, counterbalanced order. In the early evening (end of exercise 3.5 h before bedtime), participants performed either: (i) a 1 h high-intensity interval running session (HIGH, 6 × 5 min at 90% VO2peak interspersed with 5 min recovery); (ii) a 1 h low-intensity running session (LOW, 60 min at 45% VO2peak) or (iii) no exercise (CON). Subsequent nocturnal sleep was assessed using polysomnography, wristwatch actigraphy, and subjective sleep quality. A two-lead electrocardiogram recorded nocturnal cardiac autonomic activity. Results Total sleep time increased after HIGH (477.4 ± 17.7 min, p = 0.022) and LOW (479.6 ± 15.6 min, p = 0.006) compared with CON (462.9 ± 19.0 min). Time awake was lower after HIGH (31.8 ± 18.5 min, p = 0.047) and LOW (30.4 ± 15.7 min, p = 0.008) compared with CON (46.6 ± 20.0 min). There were no differences between conditions for actigraphy and subjective sleep quality (p > 0.05). Nocturnal heart rate variability was not different between conditions, but average nocturnal heart rate increased after HIGH (50 ± 5 beats min−1) compared with LOW (47 ± 5 beats min−1, p = 0.02) and CON (47 ± 5 beats min−1, p = 0.028). Conclusion When performed in the early evening, high-intensity exercise does not disrupt and may even improve subsequent nocturnal sleep in endurance-trained runners, despite increased cardiac autonomic activity. Additionally, low-intensity exercise induced positive changes in sleep behaviour that are comparable to those obtained following high-intensity exercise.

The study aimed to determine the effects of self-regulated and variable intensities sustained during short-term heat acclimation training on cycling performance. Seventeen competitive-level male athletes performed a twenty-kilometre cycling time trial before (TT-PRE), immediately after (TT-POST1) and one week after (TT-POST2) a 5-day acclimation training program, including either RPE-regulated intermittent (HA-HIT, N=9) or fixed and low-intensity (HA-LOW, N=8) training sessions in the heat (39 °C; 40 % relative humidity). Total training volume was 23 % lower in HA-HIT compared to HA-LOW. Physiological responses were evaluated during a forty-minute fixed-RPE cycling exercise performed before (HST-PRE) and immediately after (HST-POST) heat acclimation. All participants in HA-LOW group tended to improve mean power output from TT-PRE to TT-POST1 (+8.1 ± 5.2 %; ES = 0.55 ± 0.23), as well as eight of the nine athletes in HA-HIT group (+4.3 ± 2.0 %; ES = 0.29 ± 0.31) without difference between groups, but TT-POST2 results showed that improvements were dissipated one week after. Similar improvements in thermal sensation and lower elevations of core temperature in HST-POST following HA-LOW and HA-HIT training protocols suggest that high intensity and RPE regulated bouts could be an efficient strategy for short term heat acclimation protocols, for example prior to the competition. Furthermore, the modest impact of lowered thermal sensation on cycling performance confirms that perceptual responses of acclimated athletes are dissociated from physiological stress when exercising in the heat.