François Bieuzen

Effects of Whole-Body Cryotherapy vs. Far-Infrared vs. Passive Modalities on Recovery from Exercise-Induced Muscle Damage in Highly-Trained Runners

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.

whole-body cryotherapy: empirical evidence and theoretical perspectives

Whole-body cryotherapy (WBC) involves short exposures to air temperatures below −100°C. WBC is increasingly accessible to athletes, and is purported to enhance recovery after exercise and facilitate rehabilitation postinjury. Our objective was to review the efficacy and effectiveness of WBC using empirical evidence from controlled trials. We found ten relevant reports; the majority were based on small numbers of active athletes aged less than 35 years. Although WBC produces a large temperature gradient for tissue cooling, the relatively poor thermal conductivity of air prevents significant subcutaneous and core body cooling. There is weak evidence from controlled studies that WBC enhances antioxidant capacity and parasympathetic reactivation, and alters inflammatory pathways relevant to sports recovery. A series of small randomized studies found WBC offers improvements in subjective recovery and muscle soreness following metabolic or mechanical overload, but little benefit towards functional recovery. There is evidence from one study only that WBC may assist rehabilitation for adhesive capsulitis of the shoulder. There were no adverse events associated with WBC; however, studies did not seem to undertake active surveillance of predefined adverse events. Until further research is available, athletes should remain cognizant that less expensive modes of cryotherapy, such as local ice-pack application or cold-water immersion, offer comparable physiological and clinical effects to WBC.

Where are all the female participants in Sports and Exercise Medicine research

Abstract The aim of this study is to estimate the ratio of male and female participants in Sports and Exercise Medicine research. Original research articles published in three major Sports and Exercise Medicine journals (Medicine and Science in Sports and Exercise, British Journal of Sports Medicine and American Journal of Sports Medicine) over a three-year period were examined. Each article was screened to determine the following: total number of participants, the number of female participants and the number of male participants. The percentage of females and males per article in each of the journals was also calculated. Cross tabulations and Chi-square analysis were used to compare the gender representation of participants within each of the journals. Data were extracted from 1382 articles involving a total of 6,076,580 participants. A total of 2,366,968 (39%) participants were female and 3,709,612 (61%) were male. The average percentage of female participants per article across the journals ranged from 35% to 37%. Females were significantly under-represented across all of the journals (χ2 = 23,566, df = 2, p < 0.00001). In conclusion, Sports and Exercise Medicine practitioners should be cognisant of sexual dimorphism and gender disparity in the current literature.

Morning‐to‐Evening Differences in Oxygen Uptake Kinetics in Short‐Duration Cycling Exercise

This study analyzed diurnal variations in oxygen (O2) uptake kinetics and efficiency during a moderate cycle ergometer exercise. Fourteen physically active diurnally active male subjects (age 23±5 yrs) not specifically trained at cycling first completed a test to determine their ventilatory threshold (Tvent) and maximal oxygen consumption (VO2max); one week later, they completed four bouts of testing in the morning and evening in a random order, each separated by at least 24 h. For each period of the day (07:00–08:30 h and 19:00–20:30 h), subjects performed two bouts. Each bout was composed of a 5 min cycling exercise at 45 W, followed after 5 min rest by a 10 min cycling exercise at 80% of the power output associated with Tvent. Gas exchanges were analyzed breath‐by‐breath and fitted using a mono‐exponential function. During moderate exercise, the time constant and amplitude of VO2 kinetics were significantly higher in the morning compared to the evening. The net efficiency increased from the morning to evening (17.3±4 vs. 20.5±2%; p<0.05), and the variability of cycling cadence was greater during the morning than evening (+34%; p<0.05). These findings suggest that VO2 responses are affected by the time of day and could be related to variability in muscle activity pattern.

Contrast Water Therapy and Exercise Induced Muscle Damage: A Systematic Review and Meta-Analysis

The aim of this systematic review was to examine the effect of Contrast Water Therapy (CWT) on recovery following exercise induced muscle damage. Controlled trials were identified from computerized literature searching and citation tracking performed up to February 2013. Eighteen trials met the inclusion criteria; all had a high risk of bias. Pooled data from 13 studies showed that CWT resulted in significantly greater improvements in muscle soreness at the five follow-up time points (<6, 24, 48, 72 and 96 hours) in comparison to passive recovery. Pooled data also showed that CWT significantly reduced muscle strength loss at each follow-up time (<6, 24, 48, 72 and 96 hours) in comparison to passive recovery. Despite comparing CWT to a large number of other recovery interventions, including cold water immersion, warm water immersion, compression, active recovery and stretching, there was little evidence for a superior treatment intervention. The current evidence base shows that CWT is superior to using passive recovery or rest after exercise; the magnitudes of these effects may be most relevant to an elite sporting population. There seems to be little difference in recovery outcome between CWT and other popular recovery interventions.

Parasympathetic Activity and Blood Catecholamine Responses Following a Single Partial-Body Cryostimulation and a Whole-Body Cryostimulation

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.

Effect of wearing compression stockings on recovery after mild exercise-induced muscle damage.

BACKGROUND Compression garments are increasingly popular in long-distance running events where they are used to limit cumulative fatigue and symptoms associated with mild exercise-induced muscle damage (EIMD). However, the effective benefits remain unclear. OBJECTIVE This study examined the effect of wearing compression stockings (CS) on EIMD indicators. Compression was applied during or after simulated trail races performed at competition pace in experienced off-road runners. METHODS Eleven highly trained male runners participated in 3 simulated trail races (15.6 km: uphill section 6.6 km, average gradient 13%, and downhill section 9.0 km, average gradient -9%) in a randomized crossover trial. The effect of wearing CS while running or during recovery was tested and compared with a control condition (ie, run and recovery without CS; non- CS). Indicators of muscle function, muscle damage (creatine kinase; CK), inflammation (interleukin-6; IL-6), and perceived muscle soreness were recorded at baseline (1 h before warm-up) and 1, 24, and 48 h after the run. RESULTS Perceived muscle soreness was likely to be lower when participants wore CS during trail running compared with the control condition (1 h postrun, 82% chance; 24 h postrun, 80% chance). A likely or possibly beneficial effect of wearing CS during running was also found for isometric peak torque at 1 h postrun (70% chance) and 24 h postrun (60% chance) and throughout the recovery period on countermovement jump, compared with non-CS. Possible, trivial, or unclear differences were observed for CK and IL-6 between all conditions. CONCLUSION Wearing CS during simulated trail races mainly affects perceived leg soreness and muscle function. These benefits are visible very shortly after the start of the recovery period.

The influence of wearing compression stockings on performance indicators and physiological responses following a prolonged trail running exercise

Abstract The objective of this study was to investigate the effects of wearing compression socks (CS) on performance indicators and physiological responses during prolonged trail running. Eleven trained runners completed a 15.6 km trail run at a competition intensity whilst wearing or not wearing CS. Counter movement jump, maximal voluntary contraction and the oxygenation profile of vastus lateralis muscle using near-infrared spectroscopy (NIRS) method were measured before and following exercise. Run time, heart rate (HR), blood lactate concentration and ratings of perceived exertion were evaluated during the CS and non-CS sessions. No significant difference in any dependent variables was observed during the run sessions. Run times were 5681.1±503.5 and 5696.7±530.7 s for the non-CS and CS conditions, respectively. The relative intensity during CS and non-CS runs corresponded to a range of 90.5–91.5% HRmax. Although NIRS measurements such as muscle oxygen uptake and muscle blood flow significantly increased following exercise (+57.7% and + 42.6%,+59.2% and + 32.4%, respectively for the CS and non-CS sessions, P<0.05), there was no difference between the run conditions. The findings suggest that competitive runners do not gain any practical or physiological benefits from wearing CS during prolonged off-road running.

Muscle Strength and Metabolism in Master Athletes

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 p<0.05) 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, p>0.05). 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.

Endurance and strength training effects on physiological and muscular parameters during prolonged cycling

PURPOSE This study investigated the effects of a combined endurance and strength training on the physiological and neuromuscular parameters during a 2-h cycling test. METHODS Fourteen triathletes were assigned to an endurance-strength training group and an endurance-only training group. They performed three experimental trials before and after training: an incremental cycling test to exhaustion, a maximal concentric lower-limbs strength measurement and a 2-h cycling exercise. Physiological parameters, free cycling chosen cadence and the EMG of Vastus Lateralis (VL) and Rectus Femoris (RF) were analysed during the 2-h cycling task before and after a strength training programme of 5 weeks (three times per week). RESULTS The results showed that the maximum strength and the isometric maximal voluntary contraction (isoMVC) after training were significantly higher (P<0.01) and lower (P<0.01) than those before training, respectively, in endurance-strength training group and endurance-only group. The physiological variables measured during the cycling tests and the progressive increase (P<0.01) in EMGi(VL) and EMGi(RF) throughout the 2-h cycling test did not differ between the two groups before and after training, except for the variation of EMGi(VL) over the cycle time which was stabilized during the second hour of the 2-h cycling test due to training in endurance-strength training group. The decrease in free cycling chosen cadence observed in pre-training (P<0.01) was also replaced by a steady free cycling chosen cadence for the endurance-strength training group during the second hour of exercise. CONCLUSION This study confirmed the decrease in the free cycling chosen cadence with exercise duration and demonstrated that a specific combined endurance and strength training can prevent this decrease during a 2-h constant cycling exercise.