Friday, March 28, 2014

Effect of cryotherapy on performance: what's new?

Open Access J Sports Med. 2014 Mar 10;5:25-36. eCollection 2014.

Whole-body cryotherapy: empirical evidence and theoretical perspectives. Bleakley CM, Bieuzen F, Davison GW, Costello JT.

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.

FULL paper

Int J Sports Physiol Perform. 2013 May;8(3):227-42. Epub 2013 Feb 20.
Cooling and performance recovery of trained athletes: a meta-analytical review. Poppendieck W, Faude O, Wegmann M, Meyer T.

PURPOSE: Cooling after exercise has been investigated as a method to improve recovery during intensive training or competition periods. As many studies have included untrained subjects, the transfer of those results to trained athletes is questionable. METHODS: Therefore, the authors conducted a literature search and located 21 peer-reviewed randomized controlled trials addressing the effects of cooling on performance recovery in trained athletes. RESULTS: For all studies, the effect of cooling on performance was determined and effect sizes (Hedges' g) were calculated. Regarding performance measurement, the largest average effect size was found for sprint performance (2.6%, g = 0.69), while for endurance parameters (2.6%, g = 0.19), jump (3.0%, g = 0.15), and strength (1.8%, g = 0.10), effect sizes were smaller. The effects were most pronounced when performance was evaluated 96 h after exercise (4.3%, g = 1.03). Regarding the exercise used to induce fatigue, effects after endurance training (2.4%, g = 0.35) were larger than after strength-based exercise (2.4%, g = 0.11). Cold-water immersion (2.9%, g = 0.34) and cryogenic chambers (3.8%, g = 0.25) seem to be more beneficial with respect to performance than cooling packs (-1.4%, g= -0.07). For cold-water application, whole-body immersion (5.1%, g = 0.62) was significantly more effective than immersing only the legs or arms (1.1%, g = 0.10). CONCLUSIONS: In summary, the average effects of cooling on recovery of trained athletes were rather small (2.4%, g = 0.28). However, under appropriate conditions (whole-body cooling, recovery from sprint exercise), postexercise cooling seems to have positive effects that are large enough to be relevant for competitive athletes.

J Strength Cond Res. 2014 Mar 11. [Epub ahead of print]
Effect of run training and cold-water immersion on subsequent cycle training quality in high performance triathletes. Rowsell GJ, Reaburn P, Toone R, Smith M, Coutts AJ.

The purpose of the study was to investigate the effect of cold-water immersion (CWI) on physiological, psychological, and biochemical markers of recovery and subsequent cycling performance following intensive run training. Seven high-performance male triathletes (age: 28.6±7.1 y; cycling VO2peak: 73.4±10.2 mL·kg·min) completed two trials in a randomized crossover design consisting of 7 x 5-min running intervals at 105% of Individual Anaerobic Threshold followed by either CWI (10°C±0.5°C) or thermoneutral water immersion (TNI; 34±0.5°C). Subjects immersed their legs in water five times for 60-s with 60-s passive rest between each immersion. Nine hours post-immersion, inflammatory and muscle damage markers, and perceived recovery measures were obtained before the subjects completed a 5-min maximal cycling test followed by a high quality cycling interval training set (6 x 5-min intervals). Power output, heart rate (HR), blood lactate (La) and rating of perceived exertion (RPE) were also recorded during the cycling time-trial and interval set. Performance was enhanced (change, ±90% confidence limits) in the CWI condition during the cycling interval training set (power output (W·kg ), 2.1±1.7%, La (mmol·L), 18±18.1%, La:RPE, 19.8±17.5%). However, there was an unclear effect of CWI on 5-min maximal cycling time-trial performance and there was no significant influence on perceptual measures of fatigue/recovery, despite small to moderate effects. The effect of CWI on the biochemical markers was mostly unclear, however there was a substantial effect for interleukin-10 (20±13.4%). These results suggest that compared to TNI, CWI may be effective for enhancing cycling interval training performance following intensive interval running training.

J Sport Rehabil. 2014 Mar 12. [Epub ahead of print]
Comparison of Electrical Stimulation Versus Cold Water Immersion Treatment on Muscle Soreness Following Resistance Exercise. Jajtner AR, Hoffman JR, Gonzalez AM, Worts P, Fragala MS, Stout JR.

CONTEXT: Resistance training is a common form of exercise for competitive and recreational athletes. Enhancing recovery from resistance training may potentially improve the muscle remodeling processes, stimulating a faster return to peak performance. OBJECTIVE: To examine the effects of two different recovery modalities, neuromuscular electrical stimulation (NMES), and cold water immersion (CWI) on performance, biochemical and ultrasonographic measures. PARTICIPANTS: Thirty resistance-trained males (23.1±2.9yrs; 175.2±7.1cm; 82.1±8.4kg) were randomly assigned to NMES, CWI or control (CON). DESIGN AND SETTING: All participants completed a high-volume lower-body resistance training workout on day one and returned to the Human Performance Lab 24- (24H) and 48h (48H) post-exercise for follow-up testing. MEASURES: Blood samples were obtained pre-exercise (PRE), immediately post (IP), 30-minutes post (30P), 24H and 48H. Subjects were examined for performance changes in the squat exercise (total repetitions, and average power per repetition), biomarkers of inflammation, and changes in cross sectional area (CSA) and echo intensity (EI) of the rectus femoris (RF) and vastus lateralis (VL) muscles. RESULTS: No differences between groups were observed in the number of repetitions (p=0.250; power: p=0.663). Inferential based analysis indicated that increases in C-reactive protein (CRP), concentrations were likely increased by a greater magnitude following CWI compared to CON, while NMES possibly decreased more than CON from IP to 24H. Increases in IL-10 concentrations between IP-30P were likely greater in CWI than NMES, but not different compared to CON. Inferential based analysis of RF EI indicated a likely decrease for CWI between IP-48H. No other differences between groups were noted in any other muscle architecture measures. CONCLUSIONS: Results indicated that CWI induced greater increases in pro- and anti-inflammatory markers, while decreasing RF EI, suggesting CWI may be effective in enhancing short-term muscle recovery following high-volume bouts of resistance exercise.

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