Effects of cold water immersion and compression garment use after eccentric exercise on recovery

Skin temperature normalizes faster than pressure pain thresholds, pain intensity, and pain distribution during recovery from eccentric exercise

INTRODUCTION

Acute musculoskeletal injuries have diverse symptomatology and a multidimensional recovery process, including changes in swelling, redness, hyperalgesia, and expanded pain distribution. In a small proportion of cases, the tissue heals, although these symptoms persist, reflecting altered peripheral and central pain mechanisms. However, the otherwise healthy multidimensional recovery process following damage and pain is less than clear. The objective was to assess mechanical muscle hyperalgesia, skin temperature, and pain intensity and distribution during the recovery process in response to eccentric exercise in the hamstring muscles.

METHODS

Twenty-four healthy males participated in four sessions (Day-0, Day-2, Day-4, and Day-7). Exercise-induced muscle soreness was induced on Day-0 by five sets of 20 repetitions of an eccentric exercise involving the hamstrings on the dominant leg. Each session included assessments of thermography, pressure pain thresholds (PPTs), pain intensity, and area of exercise-induced pain.

RESULTS

Decreased PPTs (P < 0.005), higher pain intensity (P < 0.001), and a larger area of pain (P < 0.001) were displayed on Day-2 and Day-4 than Day-0. Skin temperature decreased on Day-2 than Day-0 (P < 0.01) and returned to baseline assessments by Day-4, despite lower temperature than the contralateral tight (P < 0.01). Further, there was a positive correlation between pain intensity and area on Day-2 and Day-4 (P < 0.005), but no for changes in skin temperature.

CONCLUSION

Thermographic changes and pain-related variables altered following eccentric exercise demonstrate different recovery times. These results provide insights into potential mechanisms and measures that can be used to assess recovery from exercise-induced damage.

EFFECT OF AQUATIC EXERCISE AFTER ECCENTRIC CONTRACTION-INDUCED MUSCLE INJURY

ABSTRACT Introduction: Muscle microlesions produced by eccentric contractions (EC) cause changes in strength, endurance, power and neuromuscular activity parameters for an extended period of time. Objectives: To investigate the effect of aquatic exercise after EC-induced muscle injury on strength, endurance, power and neuromuscular activity parameters. Methods: A cross-sectional experimental study with six subjects (age 25 ± 4 years, weight 77 ± 4kg and height of 162 ± 2 cm) with EC-induced muscle injury followed up during a recovery period (48h, 72h and 96h) without intervention (Group 1A) and involving aquatic exercises (Group 1B). Dynamic and isometric strength, muscular endurance, and vertical/horizontal power tests as well as vastus lateralis neuromuscular activity measurements were performed before, immediately after, and during the recovery period. Results: Our results indicate that the intervention in Group 1B, when compared to Group 1A, accelerated the recovery of dynamic (p <0.01) and isometric (p <0.03) strength at 48h and 72h, increased vertical power at 48h (p <0.05) and horizontal power at 48h and 72h (p <0.05), and reduced neuromuscular activity (p <0.05) at 48h and 72h after EC. Conclusions: According to our findings, performing aquatic exercises during the recovery period improves muscle efficiency and accelerates strength, power and neuromuscular activity recovery. Level of evidence l; Randomized clinical trial.

Endocrine and Metabolic Responses to Endurance Exercise Under Hot and Hypoxic Conditions

Purpose

We explored the effect of heat stress during an acute endurance exercise session in hypoxia on endocrine and metabolic responses.

Methods

A total of 12 healthy males cycled at a constant workload (60% of the power output associated with their maximal oxygen uptake under each respective condition) for 60 min in three different environments: exercise under hot and hypoxia (H+H; fraction of inspiratory oxygen or FiO₂: 14.5%, 32°C), exercise under hypoxia (HYP; FiO₂: 14.5%, 23°C), and exercise under normoxia (NOR; FiO₂: 20.9%, 23°C). After completing the exercise, participants remained in the chamber for 3 h to evaluate metabolic and endocrine responses under each environment. Changes in muscle oxygenation (only during exercise), blood variables, arterial oxygen saturation, and muscle temperature were determined up to 3 h after exercise.

Results

Serum erythropoietin (EPO) level was increased to similar levels in both H+H and HYP at 3 h after exercise compared with before exercise (P < 0.05), whereas no significant increase was found under NOR. No significant difference between H+H and HYP was observed in the serum EPO level, blood lactate level, or muscle oxygenation at any time (P > 0.05). Exercise-induced serum growth hormone (GH) elevation was significantly greater in H+H compared with HYP (P < 0.05) and HYP showed significantly lower value than NOR (P < 0.05). Arterial oxygen saturation during exercise was significantly lower in H+H and HYP compared with NOR (P < 0.05). Furthermore, H+H showed higher value compared with HYP (P < 0.05).

Conclusion

The serum EPO level increased significantly with endurance exercise in hypoxia. However, the addition of heat stress during endurance exercise in hypoxia did not augment the EPO response up to 3 h after completion of exercise. Exercise-induced GH elevation was significantly augmented when the hot exposure was combined during endurance exercise in hypoxia. Muscle oxygenation levels during endurance exercise did not differ significantly among the conditions. These findings suggest that combined hot and hypoxic stresses during endurance exercise caused some modifications of metabolic and endocrine regulations compared with the same exercise in hypoxia.

Myostatin A55T Genotype is Associated with Strength Recovery Following Exercise-Induced Muscle Damage

Myostatin A55T genotype is one of the candidates showing inter-individual variation in skeletal muscle phenotypes. The aim of this study was to investigate the effect of the myostatin A55T genotype on markers of muscle damage after eccentric exercise. Forty-eight young, healthy male college students (age = 24.8 ± 2.2 years, height = 176.7 ± 5.3 cm, weight = 73.7 ± 8.3 kg) were enrolled in this study, and muscle damage was induced through 50 reps of maximal eccentric muscle contraction. As markers of muscle damage, maximal isometric strength (MIS), muscle soreness, creatine kinase (CK), and aspartate transaminase (AST) were measured. Myostatin A55T genotypes were classified into homozygous myostatin A55T allele (AA, n = 34, 72%), heterozygous myostatin A55T allele (AT, n = 13, 26%), and homozygous mutant carriers (TT, n = 1, 2%). After eccentric exercise, the subjects with heterozygous for AT showed markedly quicker MIS recovery compared to the AA group (p = 0.042). However, there were no significant variations in muscle soreness (p = 0.379), CK (p = 0.955), and AST (p = 0.706) among the groups. These results suggest that AT in myostatin A55T genotype may be associated with quicker strength recovery following exercise-induced muscle damage.

Influence of lower body compression garments on cardiovascular autonomic responses prior to, during and following submaximal cycling exercise

PURPOSE

The aim of the current study was to examine the impact of lower body compression garments (CG) on cardiac autonomic control of heart rate (HR) prior to, during and following submaximal exercise.

METHODS

Thirty (15 males, 15 females) healthy, active adults undertook consecutive 10-min stages of supine rest, moderate-intensity upright cycling and supine recovery while wearing either normal clothing (CONTROL) or normal clothing plus CG tights in a randomised order. Heart rate (HR) and rating of perceived exertion (RPE) were assessed every minute while cardiovascular autonomic responses were assessed during the final 5 min of each stage via HR variability (HRV). The change in HR at 1-min (HRR1) and 2-min (HRR2) post-exercise and the time constant of HR recovery (HR_tau) were assessed as indices of cardiac autonomic reactivation. Differences between variables were assessed via repeated measures ANOVA and corrected pairwise comparisons.

RESULTS

Compared to rest, exercise resulted in a reduction of HRV that was similar for CONTROL and CG. A main effect for condition was identified for one non-linear, long-term HRV variable only with a significantly lower value (61.4 ± 47.8 vs. 67.1 ± 50.2 ms, p < 0.05) for CG compared to CONTROL. Cardiac autonomic reactivation (HRR1, 42.0 ± 16.8 vs. 45.5 ± 13.4 bpm; HRR2, 58.9 ± 10.5 vs. 58.9 ± 8.2 bpm; HR_tau, 63.4 ± 22.3 vs. 65.1 ± 23.0 s, p > 0.05) was comparable for CONTROL and CG.

CONCLUSION

Lower body CG failed to alter most cardiac autonomic responses during rest, moderate-intensity exercise or recovery. Mechanisms for potential ergogenic benefits of CG remain to be characterised.

Effect of Body Fat Percentage on Muscle Damage Induced by High-Intensity Eccentric Exercise

This study aimed to investigate the impact of percent body fat (%BF) on muscle damage after high-intensity eccentric exercise. Thirty healthy male undergraduates (mean age: 22.0 ± 2 years, height: 176.9 ± 5 cm, weight: 75.8 ± 11.6 kg) participated in this study, and they were classified according to their %BF into a high %fat group (HFG, ≥20%, n = 15) and a low %fat group (LFG, ≤15%, n = 15). For eccentric exercise, two sets of 25 reps were performed on a modified preacher curl machine using the elbow flexor muscle. Maximal isometric strength, muscle soreness (passive and active), creatine kinase (CK), and myoglobin (Mb) were measured as indices of muscle damage. The data were analyzed with repeated measures ANOVA. The results show that there is a significant group–time interaction for both CK and Mb after eccentric exercise (p = 0.007, p = 0.015, respectively), with a greater increase in the HFG than in the LFG. However, there was no significant group–time interaction for maximal isometric strength and muscle soreness (passive and active) (p > 0.05). These results suggest that %BF is a factor that alters the muscle damage indices CK and Mb, which indicate membrane disruption, after eccentric exercise.