Promoting recovery after training is essential for the improvement of performance. Accelerating recovery processes enables to increase training loads in subsequent sessions, and might therefore facilitate greater adaptations. Moreover, shorter recovery times will allow us to increase training frequency, which is of major importance in sports such as triathlon in which athletes perform several sessions per day. For these reasons, athletes use several strategies to improve recovery, including nutritional supplements (e.g., protein shake after the session) and physical strategies such as active recovery (low-intensity exercise) or the application of other methods such as massage, compression garments or electrical stimulation.
Pros of post-exercise cold exposure
Cold-water immersion (popularly known as ice baths) is one of the most popular recovery methods after an intense match or training session. This method is used under the hypothesis that cold attenuates pain perception through a reduction of neural drive (and therefore of nociceptive stimuli) and decreases blood flow, thus limiting the production of inflammation and edema. However, is it an effective strategy to promote exercise recovery?
To answer this question, a meta-analysis published in the prestigious British Journal of Sports Medicine (Leeder, Gissane, van Someren, Gregson, & Howatson, 2012) that included 14 studies showed that cold-water immersion provides a beneficial effect on muscle pain and on serum levels of creatine kinase (a marker of muscle damage, the origin of delayed onset muscle soreness). Moreover, the authors observed a trend towards improvements in muscle function after this recovery method, although evidence was still inconclusive. Cold-water immersion appears therefore as an effective recovery strategy to alleviate exercise-induced fatigue and muscle soreness in the short term.
Cons of post-exercise cold exposure
Exercise-induced inflammation is a necessary process to obtain the adaptations elicited by training. The stress induced by training sessions results in several processes at a cellular level that eventually improve our abilities (eg., muscle hypertrophy, increases in the number of mitochondria). Thus, blocking inflammation by means of cold application might reduce these processes (McPhee & Lightfoot, 2017), and indeed recent evidence shows some side effects of this recovery method.
A study published in the Journal of Physiology (Roberts et al., 2015) analyzed a group of athletes that performed resistance training during 12 weeks, recovering after each session with either low-intensity exercise (10 minutes pedaling) or cold-water immersion (10 minutes at 10ºC). Interestingly, lower muscle mass gains (3-fold lower) were observed in those participants who recovered with cold-water immersion. Moreover, the group that performed active recovery increased muscle strength more (almost 2-fold) than that recovering with ice baths. The authors also aimed to determine the physiological mechanisms involved in these effects, analyzing for this purpose the acute anabolic and myogenic response (that is, of the adaptation of muscle fibers) to a single training session. Results were clear: both pathways were diminished when recovering with cold-water immersion.
Conclusions
Post-exercise cold exposure (i.e., cold application or ice baths) can be a recommended strategy to fasten recovery between sessions if the goal is to attenuate muscle soreness and the associated performance impairment not minding the adaptations induced by that session, such as during a 2-day tournament or after each stage of a cycling tour. However, this strategy seems to block the pathways involved in exercise-induced muscle adaptations, reducing the gains in muscle mass and strength in the long term. Therefore, its routine inclusion in the training program might not be recommendable if the target is to improve performance or body composition. These results highlight the important role of exercise-induced stress (e.g., inflammation, production of reactive oxygen species) on training adaptations, and show that reducing this stress with cold application or other methods (e.g., anti-inflammatory drugs, supplementation with anti-oxidants) might reduce the gains.
REFERENCES
Leeder, J., Gissane, C., van Someren, K., Gregson, W., & Howatson, G. (2012). Cold water immersion and recovery from strenuous exercise: a meta-analysis. British Journal of Sports Medicine, 46(4), 233–240. //doi.org/10.1136/bjsports-2011-090061
McPhee, J. S., & Lightfoot, A. P. (2017). Post-exercise recovery regimes: blowing hot and cold. Journal of Physiology, 595(3), 627–628. //doi.org/10.1113/JP273503
Roberts, L. A., Raastad, T., Markworth, J. F., Figueiredo, V. C., Egner, I. M., Shield, A., … Peake, J. M. (2015). Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. The Journal of Physiology, 593(18), 4285–4301. //doi.org/10.1113/JP270570
