The Effects of Age and Body Fat Content on Post Downhill Run Recovery following Whole Body Cryotherapy

Whole Body Cryotherapy (WBC) is an evolving tool for post exercise recovery with effects including alleviation of muscle torque decrements, soreness, inflammation and improving wellbeing and sleep. Nonetheless, the overall efficacy of WBC for sports recovery remains equivocal. This study explored the effects of WBC following a downhill running bout, an established eccentrically biased muscle damage-inducing exercise model. Additionally, since individual factors in response to cryotherapy remain under investigated, the potential impact of age and body fat percentages on the response to WBC was examined. Following institutional ethical approval, 34 healthy male participants (mean ± SD age 41.2 ± 13.9 years; body mass 75.4 ± 11.2kg; body fat 18.8 ± 4.5%) were randomly allocated into either a WBC (n = 26) or control (CON, n = 8) group. To assess influences of differing ages and body fat contents, the WBC group was divided into old (OLD, ≥45 years, n = 10) and young (YNG, <40 years, n = 13), as well as high fat (HFAT, ≥20%, n = 10) and low fat (LFAT≤15%, n = 8) groups. Participants completed a 30 minute downhill run (15% gradient) at 60% of individual VO2 max. The WBC group underwent cryotherapy treatment (3 mins, −120°C) 1 hour post-run and CON participants passively recovered in a controlled environment (20°C). Maximal isometric leg muscle torque was assessed pre and 24 hours post-run. Blood creatine kinase (CK), muscle soreness and wellbeing were assessed pre, post, 1 hour and 24 hours post-run. Tympanic and skin temperatures were assessed pre, post-run and post-WBC. WBC did not significantly mitigate the decrease in muscle torque caused by the downhill run (WBC: 220.6 ± 61.4 Nm vs. 208.3 ± 67.6 Nm, P = 0.01; CON: 246.1 ± 47.1 Nm vs. 220.1 ± 37.5 Nm, P < 0.01). There was also an increase in muscle soreness (P < 0.01) and blood CK (P < 0.01) 24 hours post for both WBC and CON with no difference between groups. There was a significant decrease in muscle torque in OLD participants (178.3 ± 37.5 Nm vs. 155.7 ± 49.2, P = 0.04) but no decrease in YNG participants (257.3 ± 60.7 Nm vs. 253.3 ± 54.0 Nm, P = 0.55), following WBC. There were no differences between HFAT and LFAT groups (all P values >0.05). WBC does not significantly repair muscle damage in healthy males, however WBC may benefit the recovery of muscle strength following eccentrically based exercises in young individuals. Body fat content does not appear to influence the WBC response post exercise.