The Effects of Cold Water Immersion and Active Recovery on Molecular Factors That Regulate Growth and Remodeling of Skeletal Muscle After Resistance Exercise

Cold water immersion regulates NLRP3 inflammasome pathway in the rat skeletal muscle after eccentric exercise by regulating the ubiquitin proteasome related proteins

BACKGROUND

Eccentric exercise (ECC) can induce NLRP3-related inflammation in skeletal muscle tissue. Limited available data have shown that Cold water immersion (CWI) after ECC can suppress skeletal muscle inflammation. This study aims to investigate the effect of CWI after ECC on the NLRP3 inflammasome pathway, and the expression of ubiquitin-proteasome-related proteins (UPPs) in the skeletal muscle of rats.

METHODS

Twenty-five male Wistar rats were randomly divided into control, ECC, ECC + CWI, ECC + NWI (normal water immersion), and ECC + AR (active recovery) groups. The Eccentric exercise consisted of 90 min of downhill running on a treadmill with a speed of 16 m/min and -16° incline. Animals in the NWI and CWI groups were immersed in water at 25 °C and 10 °C after ECC. Eventually, The soleus muscle was isolated and the expression of NLRP3, caspase-1, FBXL2, TRIM31, and PARKIN was evaluated by western blot. Tissue levels of IL-1β and IL-18 were measured by ELISA assay.

RESULTS

ECC significantly increased the expression of NLRP3, caspase-1, and the tissue levels of IL-1β and IL-18 compared to the control group. After ECC, FBXL2, and PARKIN were downregulated, whereas TRIM31 was up-regulated (P < 0.05). CWI after ECC suppressed the NLRP3 inflammasome components and increased the protein levels of FBXL2 and TRIM31 at higher levels than other recovery methods (P < 0.05). CWI and AR had the same increase in PARKIN expression and the same decrease in CK level compared to the ECC group (P < 0.05).

CONCLUSION

Our results indicated that CWI increased the expression of NLRP3-related UPPs in concomitant with suppression of NLRP3 in the soleus muscle of rats after ECC. As a result the beneficial effects of CWI on the attenuation of skeletal muscle inflammation may contribute to an alteration of UPPs expression.

The isolated effects of local cold application on proteolytic and myogenic signaling

Post-exercise cooling studies reveal inhibitory effects on markers of skeletal muscle growth. However, the isolated effect of local cold application has not been adequately addressed. It is unclear if the local cold or the combination of local cold and exercise is driving negatively altered skeletal muscle gene expression. The purpose was to determine the effects of a 4 h local cold application to the vastus lateralis on the myogenic and proteolytic response. Participants (n = 12, 27 ± 6 years, 179 ± 9 cm, 82.8 ± 13.0 kg, 18.4 ± 7.1 %BF) rested with a thermal wrap placed on each leg with either circulating cold fluid (10 °C, COLD) or no fluid circulation (room temperature, RT). Muscle samples were collected to quantify mRNA (RT-qPCR) and proteins (Western Blot) associated with myogenesis and proteolysis. Temperatures in COLD were lower than RT at the skin (13.2 ± 1.0 °C vs. 34.8 ± 0.9 °C; p < 0.001) and intramuscularly (20.5 ± 1.3 °C vs. 35.6 ± 0.8 °C, p < 0.001). Myogenic-related mRNA, MYO-G and MYO-D1, were lower in COLD (p = 0.001, p < 0.001, respectively) whereas myogenic-mRNA, MYF6, was greater in COLD (p = 0.002). No other myogenic associated genes were different between COLD and RT (MSTN, p = 0.643; MEF2a, p = 0.424; MYF5, p = 0.523; RPS3, p = 0.589; RPL3-L, p = 0.688). Proteolytic-related mRNA was higher in COLD (FOXO3a, p < 0.001; Atrogin-1, p = 0.049; MURF-1, p < 0.001). The phosphorylation:total protein ratio for the translational repressor of muscle mass, 4E-BP1Thr37/46, was lower in COLD (p = 0.043), with no differences in mTORser2448 (p = 0.509) or p70S6K1Thr389 (p = 0.579). Isolated local cooling over 4 h exhibits inhibited myogenic and higher proteolytic skeletal muscle molecular response.

Cold water immersion in recovery following a single bout resistance exercise suppresses mechanisms of miRNA nuclear export and maturation

Cold water immersion (CWI) following intense exercise is a common athletic recovery practice. However, CWI impacts muscle adaptations to exercise training, with attenuated muscle hypertrophy and increased angiogenesis. Tissue temperature modulates the abundance of specific miRNA species and thus CWI may affect muscle adaptations via modulating miRNA expression following a bout of exercise. The current study focused on the regulatory mechanisms involved in cleavage and nuclear export of mature miRNA, including DROSHA, EXPORTIN-5, and DICER. Muscle biopsies were obtained from the vastus lateralis of young males (n = 9) at rest and at 2, 4, and 48 h of recovery from an acute bout of resistance exercise, followed by either 10 min of active recovery (ACT) at ambient temperature or CWI at 10°C. The abundance of key miRNA species in the regulation of intracellular anabolic signaling (miR-1 and miR-133a) and angiogenesis (miR-15a and miR-126) were measured, along with several gene targets implicated in satellite cell dynamics (NCAM and PAX7) and angiogenesis (VEGF and SPRED-1). When compared to ACT, CWI suppressed mRNA expression of DROSHA (24 h p = 0.025 and 48 h p = 0.017), EXPORTIN-5 (24 h p = 0.008), and DICER (24 h p = 0.0034). Of the analyzed miRNA species, miR-133a (24 h p < 0.001 and 48 h p = 0.007) and miR-126 (24 h p < 0.001 and 48 h p < 0.001) remained elevated at 24 h post-exercise in the CWI trial only. Potential gene targets of these miRNA, however, did not differ between trials. CWI may therefore impact miRNA abundance in skeletal muscle, although the precise physiological relevance needs further investigation.

Cold for centuries: a brief history of cryotherapies to improve health, injury and post-exercise recovery

For centuries, cold temperatures have been used by humans for therapeutic, health and sporting recovery purposes. This application of cold for therapeutic purposes is regularly referred to as cryotherapy. Cryotherapies including ice, cold-water and cold air have been popularised by an ability to remove heat, reduce core and tissue temperatures, and alter blood flow in humans. The resulting downstream effects upon human physiologies providing benefits that include a reduced perception of pain, or analgesia, and an improved sensation of well-being. Ultimately, such benefits have been translated into therapies that may assist in improving post-exercise recovery, with further investigations assessing the role that cryotherapies can play in attenuating the ensuing post-exercise inflammatory response. Whilst considerable progress has been made in our understanding of the mechanistic changes associated with adopting cryotherapies, research focus tends to look towards the future rather than to the past. It has been suggested that this might be due to the notion of progress being defined as change over time from lower to higher states of knowledge. However, a historical perspective, studying a subject in light of its earliest phase and subsequent evolution, could help sharpen one's vision of the present; helping to generate new research questions as well as look at old questions in new ways. Therefore, the aim of this brief historical perspective is to highlight the origins of the many arms of this popular recovery and treatment technique, whilst further assessing the changing face of cryotherapy. We conclude by discussing what lies ahead in the future for cold-application techniques.

Increasing the resting time between drop jumps lessens delayed-onset muscle soreness and limits the extent of prolonged low-frequency force depression in human knee extensor muscles

PURPOSE

Unaccustomed eccentric contractions generally result in a long-lasting contractile impairment, referred to as prolonged low-frequency force depression (PLFFD), and delayed-onset muscle soreness (DOMS). We here used repeated drop jumps (DJs) as an eccentric contraction model and studied the effects of increasing the time between DJs from 20 s to 5 min. We hypothesized that both PLFFD and DOMS would be less marked at the longer DJ interval due to the longer time to restore structural elements between DJs.

METHODS

Young men (n = 12) randomly performed 50 DJs with either 20-s (DJ-20 s) or 5-min (DJ-5 min) rest between DJs. Voluntary, 20 Hz and 100 Hz electrically stimulated isometric knee extension torques and muscle soreness were monitored before and for 7 days after DJs; serum CK activity was measured to assess muscle fibre protein leakage. In additional experiments, changes in mRNA levels were assessed in muscle biopsies collected before and 1 h after exercise.

RESULTS

A marked PLFFD was observed with both protocols and the extent of 20 Hz torque depression was smaller immediately and 1 day after DJ-5 min than after DJ-20 s (p < 0.05), whereas the MVC and 100 Hz torques were similarly decreased with the two protocols. Markedly larger differences between the two protocols were observed for the muscle soreness score, which 1-4 days after exercise was about two times larger with DJ-20 s than with DJ-5 min (p < 0.01).

CONCLUSIONS

The larger protective effect of the longer DJ interval against DOMS than against PLFFD indicates that their underlying mechanisms involve different structural elements.

Adaptations to Post-exercise Cold Water Immersion: Friend, Foe, or Futile?

In the last decade, cold water immersion (CWI) has emerged as one of the most popular post-exercise recovery strategies utilized amongst athletes during training and competition. Following earlier research on the effects of CWI on the recovery of exercise performance and associated mechanisms, the recent focus has been on how CWI might influence adaptations to exercise. This line of enquiry stems from classical work demonstrating improved endurance and mitochondrial development in rodents exposed to repeated cold exposures. Moreover, there was strong rationale that CWI might enhance adaptations to exercise, given the discovery, and central role of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in both cold- and exercise-induced oxidative adaptations. Research on adaptations to post-exercise CWI have generally indicated a mode-dependant effect, where resistance training adaptations were diminished, whilst aerobic exercise performance seems unaffected but demonstrates premise for enhancement. However, the general suitability of CWI as a recovery modality has been the focus of considerable debate, primarily given the dampening effect on hypertrophy gains. In this mini-review, we highlight the key mechanisms surrounding CWI and endurance exercise adaptations, reiterating the potential for CWI to enhance endurance performance, with support from classical and contemporary works. This review also discusses the implications and insights (with regards to endurance and strength adaptations) gathered from recent studies examining the longer-term effects of CWI on training performance and recovery. Lastly, a periodized approach to recovery is proposed, where the use of CWI may be incorporated during competition or intensified training, whilst strategically avoiding periods following training focused on improving muscle strength or hypertrophy.

Post-exercise Cold Water Immersion Effects on Physiological Adaptations to Resistance Training and the Underlying Mechanisms in Skeletal Muscle: A Narrative Review

Post-exercise cold-water immersion (CWI) is a popular recovery modality aimed at minimizing fatigue and hastening recovery following exercise. In this regard, CWI has been shown to be beneficial for accelerating post-exercise recovery of various parameters including muscle strength, muscle soreness, inflammation, muscle damage, and perceptions of fatigue. Improved recovery following an exercise session facilitated by CWI is thought to enhance the quality and training load of subsequent training sessions, thereby providing a greater training stimulus for long-term physiological adaptations. However, studies investigating the long-term effects of repeated post-exercise CWI instead suggest CWI may attenuate physiological adaptations to exercise training in a mode-specific manner. Specifically, there is evidence post-exercise CWI can attenuate improvements in physiological adaptations to resistance training, including aspects of maximal strength, power, and skeletal muscle hypertrophy, without negatively influencing endurance training adaptations. Several studies have investigated the effects of CWI on the molecular responses to resistance exercise in an attempt to identify the mechanisms by which CWI attenuates physiological adaptations to resistance training. Although evidence is limited, it appears that CWI attenuates the activation of anabolic signaling pathways and the increase in muscle protein synthesis following acute and chronic resistance exercise, which may mediate the negative effects of CWI on long-term resistance training adaptations. There are, however, a number of methodological factors that must be considered when interpreting evidence for the effects of post-exercise CWI on physiological adaptations to resistance training and the potential underlying mechanisms. This review outlines and critiques the available evidence on the effects of CWI on long-term resistance training adaptations and the underlying molecular mechanisms in skeletal muscle, and suggests potential directions for future research to further elucidate the effects of CWI on resistance training adaptations.