The efficacy of contemporary recovery strategies following exercise-induced muscle damage

Following exercise, a rapid return to optimal performance is desirable for athletes. Some types of physical activity can result in exercise-induced muscle damage (EIMD), an occurrence which is well documented in adult populations. Symptoms of EIMD include increases in perceived muscle soreness, decrements in muscle strength and power, alterations in limb proprioception, increased myoprotein release, increased perceived exertion during exercise, and reduced endurance performance. Many strategies are currently employed in attempts to manage the symptoms of EIMD, though the majority are based on anecdotal or equivocal evidence. The aim of this thesis was to investigate a range of contemporary recovery strategies to determine their effectiveness and appropriateness for use with athletic populations. This thesis comprises eight chapters: • Chapter 1: Introduction • Chapter 2: Review of Literature • Chapter 3: Study 1 – Cold water immersion therapy as a recovery strategy following exercise-induced muscle damage • Chapter 4: Study 2 – Manual massage as a recovery strategy following exercise-induced muscle damage • Chapter 5: Study 3 – The use of compressive clothing as a recovery strategy following exercise-induced muscle damage • Chapter 6: Study 4 – Does the use of manual massage therapy have an added beneficial effect on symptoms of exercise-induced muscle damage when used in conjunction with compressive clothing? • Chapter 7: Study 5 – Muscle strength loss characteristics at optimal and short muscle lengths following exercise-induced muscle damage • Chapter 8: General discussion • Chapter 9: Conclusion and recommendation for further study Chapter 3 considers the efficacy of a single bout of cold water immersion therapy following strenuous exercise as a recovery strategy. The results indicate that this treatment protocol has no significant effect on moderating increases in soreness or creatine kinase activity, or reducing decrements in muscle function (p > 0.05). Although this type of recovery strategy is popular in elite sporting fields, this study is consistent with a number of others, indicating that a single bout of cold water immersion therapy is an ineffective recovery strategy following EIMD. Chapter 4 focuses on manual massage a post-exercise recovery strategy. Similar to cold water immersion therapies, the use of massage as a treatment is widespread within the athletic field, though few studies have considered its efficacy following EIMD. This study indicates that although no effect of massage was apparent on perceived soreness or creatine kinase activity, individuals receiving a thirty minute treatment immediately following damaging exercise demonstrated reduced decrements in muscle strength as assessed by isokinetic dynamometry (p < 0.05). This chapter concludes that immediate manual massage may be an effective treatment strategy to manage some of the symptoms of EIMD. Chapter 5 examines the use of clothing with specific compressive qualities as an increasingly popular method of managing symptoms of muscle damage, which is largely unsupported by scientific evidence. Following damaging exercise, the use of lower limb compression reduced decrements in isokinetic muscle function and jump performance, while moderating increases in perceived soreness. This chapter concludes that the use of lower limb compression clothing is an effective, non-invasive method of managing symptoms of EIMD. Data collected from chapters 4 and 5 indicated that manual massage and lower limb compression may manage some of the symptoms of EIMD. Chapter 6 investigates whether these two recovery strategies used in combination have an additive beneficial effect on symptoms of muscle damage. Data from study 3 (chapter 5) were used to compare the combined treatment with the compressive treatment as an independent recovery modality. A significant beneficial effect was observed on perceived soreness as a result of combining the massage and compression treatments, in comparison with compression alone. No consistent benefits on muscle function, above those offered by compression independently were derived as a result of the combined treatment. This chapter concludes that although some benefits are afforded by the addition of massage to the compressive treatment with regard to perceived soreness, logistically, this combination of treatments is unlikely to provide a substantial enough benefit to warrant use with groups of athletes. Exercise-induced muscle damage leads to losses of strength and alterations in the muscle length-tension relationship. Data collated from chapters 5 and 6 were used to investigate muscle strength loss characteristics following damaging exercise. Consistent with previous research, a disproportionate loss of muscle strength was observed at shorter muscle lengths, attributable to mechanical changes within the affected muscle. The use of isokinetic dynamometry was able to detect a shift in length-tension relationship in favour of a longer optimal muscle length for tension generation. The shift in length-tension relationship has been observed in previous studies, although no study has observed this shift in the knee extensor muscle group, and those considering the knee extensor group have inferred the shift as a result of the disproportionate nature of muscle strength loss. The final chapter of this thesis uses data collected from chapters 3-6 to determine the variations in response to different types of eccentrically biased exercise. Typically, plyometric drop jumps elicited greater decrements in isokinetic muscle function and higher perceptions of soreness following exercise in comparison with either downhill running or vertical plyometric jumps. Downhill running resulted in greater cellular permeability as indicated by creatine kinase activity.EThOS - Electronic Theses Online ServiceGBUnited Kingdo