Despite acute inhibition of the PGF2α metabolite at early time points, naproxen sodium did not hinder positive morphological adaptations of the upper body in response to resistance training.

Brewer, CB, Booher, BM, and Lawton, N. Comparison of acute energy expenditure and rating of perceived exertion in equivalent bouts of circuit training and treadmill running. J Strength Cond Res XX(X): 000-000, 2018-Circuit weight training (CT) maximizes exercise density, which may lead to an inaccurate perception of energy expenditure (EE). The purpose of this study was to compare acute EE indices and rating of perceived exertion (RPE) between CT and an equivalent bout of treadmill running (TR). College-aged men (n = 9) who regularly engaged in running and resistance training performed CT first. Circuit weight training that consisted of 10 resistance stations (40% of 1 repetition maximum, 15 repetitions, 60 b·min) was performed for 20 minutes. Heart rate (HR) and EE (Cosmed K4b) were monitored continuously, and RPE was assessed consistently. A 20-min TR session was performed at the average HR maintained during CT. Dependent t-tests were used to assess differences in RPE, total EE (TEE, kcal), rate of EE (REE, kcal·min), and relative REE (RREE, kcal·kg·min) between CT and TR. Pearson's correlation was used to examine relationships between RPE and EE indices. Total EE was lower during CT (168.19 ± 16.42) than TR (244.20 ± 44.80); REE was lower during CT (8.49 ± 0.90) than TR (12.21 ± 2.24); and RREE was lower during CT (0.10 ± 0.02) than TR (0.15 ± 0.02) (all p < 0.001). Circuit weight training RPE (6.0 ± 1.1) was greater than TR (4.1 ± 0.6) (p < 0.001). There was no association between RPE and EE indices (p > 0.05). The average HR elicited by CT was 61% HR reserve. At equivalent HRs and duration, CT resulted in a significantly higher RPE but lower EE. It is imperative for participants engaged in CT to understand that although CT results in HR values within an aerobic training zone and feels more strenuous, it is not associated with greater acute EE.

The objectives of this study were to examine the use of the analgesics for the relief of exercise-associated pain (EAP) and to examine personal and/or exercise characteristics that might potentially predict such use in recreationally trained college-aged individuals. Recreationally trained college-aged students (N = 263) were invited to complete a self-administered 16-item questionnaire concerning personal exercise habits and analgesic use for EAP. The primary dependent variable was analgesic use for EAP, and additional items sought to characterize patterns and behaviors related to the use. Descriptive statistics and frequencies were calculated for all items, and logistic regression was used to evaluate the ability of 4 variables to predict analgesic use for EAP: gender, length of time performing regular exercise, weekly frequency of aerobic exercise, and weekly frequency of resistance exercise. Approximately 36% of respondents reported analgesic use for EAP, with data indicating acute use for what is generally acute pain. With predictors considered individually, gender was a significant predictor, with female respondents being more likely to use analgesics for EAP (p = 0.04). With all predictors considered concurrently, the model did not significantly contribute to the prediction of use in this sample. Potential for misuse was highlighted by a large percentage of users who described themselves as very unlikely to follow label directions and more likely to take a dose exceeding recommendations. In light of research that reports a potential detriment to muscular regeneration when analgesics are consumed with exercise, it is important to be cognizant of the use of these drugs in individuals striving to improve muscular fitness. Coaches and trainers should educate athletes about the associated risks and caution those who may unnecessarily take analgesics.

W hen hormones that mediate the development of skeletal muscle strength and hypertrophy are considered, anabolic steroids, growth hormone, and insulin-like growth factor-1 typically receive much attention. However, as the study of exercise endocrinology has expanded, roles for lesser known chemical messengers in anabolic processes have been discovered. Prostaglandin F2α (PGF2α) is one such hormone, described as an endogenously-produced growth factor. 1, 2 PGF2α is a member of the prostaglandin family of eicosanoid hormones. Prostaglandins have dual roles in regeneration and inflammation, but it is their activities in inflammation that make them the primary target of cyclooxygenase (COX)inhibitor drugs (Table 1). Indeed, much of the research that seeks to elucidate the roles of prostaglandins in skeletal muscle regeneration does so through suppression of its production with COX inhibitors. Prostaglandins have pleiotropic effects in a range of cell and tissue types. 1 Prostaglandins sensitize nociceptors in the pain response (PGE2) 3 and contribute to vasodilation and control of local blood flow control during exercise (PGE2 and PGI2). 4-6 In regards to roles in regeneration, the COX-pathway and its metabolites, specifically prostaglandins E and F, have been shown to stimulate in vitro and in vivo satellite cell proliferation, differentiation, fusion, myonuclear accretion, and mixed muscle protein synthesis in both human and animal models of injury. 1, 2, 7-17 The purpose of this article is to present literature describing roles for the COX-metabolite PGF2α in regenerative processes in skeletal muscle. With PGF2α activities inferred through consequences of its suppression with COX-inhibitors, some discussion of these drugs will also be provided, as they themselves have been the focus of much research. Due to the fact prostaglandins are induced by inflammation, various techniques have been employed throughout the body of research to elicit inflammation. Pathophysiological differences between contraction-induced injury and those resulting from strains, bruises, and lacerations must be acknowledged, as it is possible these differences account for contradictory findings between some human and animal research. Studies using non-exercise models of injury are included in this manuscript in light of the fact that COXinhibitors are often used to ameliorate pain associated musculoskeletal injuries aside from exercise. Considering the relative ease with which COX-inhibiting drugs can be procured and their use for maladies ranging from delayedonset muscle soreness to arthritis and headaches, awareness of the potential consequences of prostaglandin suppression are important to many individuals, including athletes,

No abstract