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Purpose: External counterpulsation (ECP) has previously been used to treat cardiac patients via compression of the lower extremities during diastole to increase venous return and coronary perfusion. However, the effects of ECP on exercise performance and markers of recovery in elite athletes are largely unknown. Methods: On 2 separate occasions, 48 h apart, 7 elite National Rugby League players performed an identical 60-min field-based conditioning session followed by a 30-min period ol either regular ECP treatment or placebo. Power measures during repeated cycle bouts and countermovement jump height and contraction time derivatives were measured at rest and 5 h postexercise. Saliva samples and venous blood samples were taken at rest, postexercise, and 5 h postexercise to assess stress, inflammation, and muscle damage. Results: After ECP treatment, cycling peak power output (P = .028; 11%) and accumulated peak power (P = .027; 14%) increased compared with the placebo condition. Postexercise plasma interleukin 1 receptor antagonist only increased after ECP (P= .024; 84%), and concentiations of plasma interleukin 1 receptor antagonist tended to be higher (P = .093; 76%) 5 h postexercise. Furthermore, testosterone-to-cortisolratio was increased above baseline and placebo 5 h postexercise (P = .017-029; 24-77%). The ratio of postexercise salivary a-amylase to immunoglobulin A decreased after treatment (P = .013; 50%) compared with the placebo contiol. Conclusions. Exercise performance and hormonal indicators of stress were improved and inflammation markers were reduced following acute ECP. [ABSTRACT FROM AUTHOR]

Measuring alterations in redox homoeostasis in athletes can provide insights into their responses to training such as adaptations or fatigued states. However, redox monitoring is impractical in athletes given the time burden of venepuncture and subsequent laboratory assays. The ability of point-of-care tests (POC): 1) Free Oxygen Radical Test (FORT) and 2) Free Oxygen Radical Defence (FORD), to reliably measure whole blood oxidative stress between days and after exercise is unknown as well as their relationship with laboratory measures (F2-isoprostanes, total antioxidant capacity; TAC). Participants completed two trials performed on separate days comprising blood sampling at rest (n=22) and after treadmill-running (n=14). Between-day CVs for FORT (4.6%) and FORD (4.8%) were acceptable at rest. There was no difference in the between-day magnitude of change in any biomarker from pre- to post-exercise (p>0.05), yet the within-trial change in FORD was variable (trial one: +4.5%, p=0.15; trial two: +6.3%, p<0.05). TAC and FORD were significantly correlated pre- and post-exercise (r=~0.53, p<0.05), whereas F2-isoprostanes and FORT had a significant correlation pre-exercise only (r=0.45, p=0.03). Overall, the POC tests are reliable and could be used for baseline longitudinal redox monitoring. More data is required on POC tests for assessing redox perturbations induced by exercise. [ABSTRACT FROM AUTHOR]

This study examined the relationship between dual-energy x-ray absorptiometry (DXA)-derived estimates of energy balance (EB) and changes in body composition across various seasonal phases in team sport athletes. Forty-five Australian rules footballers underwent six DXA scans across a 12-month period (off-season [OS, Week 0–13], early [PS1, Week 13–22] and late pre-season [PS2, Week 22–31] and early [IS1, Week 3–42] and late in-season [IS2, Week 42–51]). EB (kcal·day−1) was estimated from changes in fat free soft tissue mass (FFSTM) and fat mass (FM) between scans according to a validated formula. An EB threshold of ± 123 kcal·day−1 for >60 days demonstrated a very likely (>95% probability) change in FFSTM (>1.0 kg) and FM (>0.7 kg). There were small to almost perfect relationships between EB and changes in FM (r = 0.97, 95% CI, 0.96–0.98), FFSTM (r = −0.41, −0.92 to −0.52) and body mass (r = 0.27, 0.14–0.40). EB was lowest during PS1 compared to all other phases (range, −265 to −142 kcal·day−1), with no other changes at any time. Increases in FFSTM were higher during OS compared to PS2 (1.6 ± 0.4 kg), and higher during PS1 compared to PS2, IS1, and IS2 (range, 1.6–2.1 kg). There were no changes during in-season (−0.1–0.05 kg). FM decreased only in PS1 compared to all other seasonal phases (−1.8 to −1.0 kg). Assessments of body composition can be used as a tool to estimate EB, which practically can be used to indicate athlete's training and nutrition behaviours/practices. [ABSTRACT FROM AUTHOR]

An increasing body of evidence suggests that age-related immune changes and chronic inflammation contribute to cancer development. Recognizing that exercise has protective effects against cancer, promotes immune function, and beneficially modulates inflammation with ageing, this review outlines the current evidence indicating an emerging role for exercise immunology in preventing and treating cancer in older adults. A specific focus is on data suggesting that muscle-derived cytokines (myokines) mediate anti-cancer effects through promoting immunosurveillance against tumourigenesis or inhibiting cancer cell viability. Previous studies suggested that the exercise-induced release of myokines and other endocrine factors into the blood increases the capacity of blood serum to inhibit cancer cell growth in vitro. However, little is known about whether this effect is influenced by ageing. Prostate cancer is the second most common cancer in men. We therefore examined the effects of serum collected before and after exercise from healthy young and older men on the metabolic activity of androgen-responsive LNCaP and androgen-unresponsive PC3 prostate cancer cells. Exercise-conditioned serum collected from the young group did not alter cell metabolic activity, whereas post-exercise serum (compared with pre-exercise serum) from the older men inhibited the metabolic activity of LNCaP cancer cells. Serum levels of candidate cancer-inhibitory myokines oncostatin M and osteonectin increased in both age groups following exercise. Serum testosterone increased only in the younger men postexercise, potentially attenuating inhibitory effects of myokines on the LNCaP cell viability. The data from our study and the evidence in this review suggest that mobilizing serum factors and immune cells may be a key mechanism of how exercise counteracts cancer in the older population. [ABSTRACT FROM AUTHOR]

Purpose: To test the hypothesis that antioxidants can attenuate high-intensity interval training-induced improvements in exercise performance. Methods: Two groups of recreationally active males performed a high-intensity interval running protocol, four times per week for 4 wk. Group 1 (n = 8) consumed 1 g of vitamin C daily throughout the training period, whereas Group 2 (n = 7) consumed a visually identical placebo. Pre- and posttraining, subjects were assessed for VO2max, 10 km time trial, running economy at 12 km/h and distance run on the YoYo intermittent recovery tests level 1 and 2 (YoYoIRTl/2). Subjects also performed a 60 min run before and after training at a running velocity of 65% of pretraining VO2max so as to assess training-induced changes in substrate oxidation rates. Results: Training improved (P < .0005) VO2max, 10 km time trial, running economy, YoYolRTl and YoYolRT2 in both groups, although there was no difference (P = .31,0.29,0.24,0.76 and 0.59) between groups in the magnitude of training-induced improvements in any of the aforementioned parameters. Similarly, training also decreased (P < .0005) mean carbohydrate and increased mean fat oxidation rates during submaximal exercise in both groups, although no differences (P = .98 and 0.94) existed between training conditions. Conclusions: Daily oral consumption of 1 g of vitamin C during a 4 wk high-intensity interval training period does not impair training-induced improvements in the exercise performance of recreationally active males. [ABSTRACT FROM AUTHOR]