The Effect of Phase Change Material on Recovery of Neuromuscular Function Following Competitive Soccer Match-Play

Abstract

Aim: Cryotherapy is commonly implemented following soccer match-play in an attempt to accelerate the natural time-course of recovery, but the effect of this intervention on neuromuscular function is unknown. The aim of the present study was to examine the effect of donning lower-body garments fitted with cooled phase change material (PCM) on recovery of neuromuscular function following competitive soccer match-play. Methods: Using a randomized, crossover design, 11 male semi-professional soccer players wore PCM cooled to 15°C (PCM cold ) or left at ambient temperature (PCM amb ; sham control) for 3 h following soccer match-play. Pre-, and 24, 48, and 72 h post-match, participants completed a battery of neuromuscular, physical, and perceptual tests. Maximal voluntary contraction force (MVC) and twitch responses to electrical (femoral nerve) and magnetic (motor cortex) stimulation (TMS) during isometric knee-extension and at rest were measured to assess central nervous system (CNS) (voluntary activation, VA) and muscle contractile (quadriceps potentiated twitch force, Q tw,pot ) function. Fatigue and perceptions of muscle soreness were assessed via visual analog scales, and physical function was assessed through measures of jump [countermovement jump (CMJ) height and reactive strength index (RSI)] performance. A belief questionnaire was completed pre- and post-intervention to determine the perceived effectiveness of each garment. Results: Competitive soccer match-play elicited persistent decrements in MVC, VA measured with femoral nerve stimulation, Q tw,pot , as well as reactive strength, fatigue and muscle soreness ( P < 0.05). Both MVC and VA were higher at 48 h post-match after wearing PCM cold compared with PCM amb ( P < 0.05). However, there was no effect of PCM on the magnitude or time-course of recovery for any other neuromuscular, physical function, or perceptual indices studied ( P > 0.05). The belief questionnaire revealed that players perceived that both PCM cold and PCM amb were moderately effective in improving recovery, with no difference between the two interventions ( P = 0.56). Conclusion: Although wearing cooled PCM garments improved MVC and VA 48 h following match-play, the lack of effect on measures of physical function or perceptual responses to match-play suggest that PCM offers a limited benefit to the recovery process. The lack of effect could have been due to the relatively small magnitude of change in most of the outcome measures studied.

Prolonging the duration of cooling does not enhance recovery following a marathon

“…The marathon led to decreases in muscle function, increases in perceptions of soreness, and increases in blood markers of muscle damage (CK) and inflammation (hsCRP). Contrary to the hypothesis, and unlike our previous work, 26–29 there was no difference in the rate of recovery between the PCM treatment and control groups. These results indicate that prolonged PCM cooling was not an effective recovery strategy when administered after running a marathon.…”

“…The present study expands upon the findings of previous studies implementing prolonged durations of PCM cooling following high intensity isolated eccentric contraction of a single muscle group 26,27 or following a soccer match 28,29 . Based on these data, it is possible that the cooling effect from the PCM packs applied locally to the quadriceps was not large enough to act systemically on a damage response occurring across several muscle groups.…”

“…Although speculative, this multifaceted cryotherapy approach could allow the athlete to sustain the treatment effect from CWI for a longer duration in the immediate post‐exercise period all the while allowing the athlete to return to normal post‐exercise activities (eg meal, relaxation, recreational activities). Future research should examine the impact of PCM application on body temperatures following exercise of metabolic nature resulting in an elevated thermal load such as marathon running to determine whether a greater cooling dose is required to elicit the previously demonstrated beneficial effects following eccentric 26,27 and team sport exercise 28,29 …”

“…However, this effect only lasted for the 15‐minute duration of CWI while it was maintained throughout the entire 3‐hour duration of PCM cooling. The influence of prolonged PCM cooling on acute physiological recovery has also been established following isolated eccentric quadriceps exercise 26,27 and following soccer match play 28,29 . Given that EIMD is a multifaceted process, an intervention strategy capable of treating the symptoms of EIMD after they manifest following eccentric exercise may not be as effective following endurance exercise.…”

Don't Lose Your Cool With Cryotherapy: The Application of Phase Change Material for Prolonged Cooling in Athletic Recovery and Beyond

“…Thus, treatment began more than 5 h after the commencement of the exercise stress. By contrast, in the two soccer studies (Clifford et al, 2018;Brownstein et al, 2019), the PCM cooling packs were applied within 30 min of exercise cessation, which would correspond to approximately 2 h after the commencement of exercise. Although evidence supports the delayed use of CWI (administered 3 h post-exercise) for accelerating recovery of inflammation and improving next day performance (Brophy-Williams et al, 2011), the exercise session performed prior to the cryotherapy treatment lasted a total duration of only 24 min.…”