Intermittent Pneumatic Compression Boot Use Elevates Blood Lactate During Subsequent Exercise.

The purpose of the present study was to investigate the influence of intermittent pneumatic compression (IPC) boot use between submaximal cycling trials on heart rate (HR) and blood lactate concentrations. Ten healthy participants (9M; 1F) performed two consecutive 60 minute rides at 60% of functional threshold power with a 30 minute rest between rides. The rest period was spent in a supine position using IPC boots (BOOT) or sitting in a similar position without boots (CON). HRs were collected every 15 minutes during cycling rides, and lactate was measured at the 30-minute mark during both rides. An identical trial was performed 7 days later with conditions (BOOT or CON) crossed. There were no between-trial differences (p > 0.05) in HR; between-trial differences were found for lactate concentrations during the second ride (3.9 ± 1.0 mmol/L BOOT vs. 2.7 ± 1.5 mmol/L CON, p < 0.05). The use of IPC boots between cycling trials as compared to laying in a supine position did not affect heart rate responses but did stimulate higher lactate concentrations during subsequent exercise.

Park Use and Physical Activity Among Mostly Low-to-Middle Income, Minority Parents and Their Children.

BACKGROUND: Limited research has examined park use and physical activity among economically and ethnically diverse families. This study fills that gap. METHODS: Parents (n = 326) completed a questionnaire about their park use (yes/no, parks visited, reasons for nonuse) and physical activity (Godin Leisure Time questionnaire). Geographical Information Systems was used to calculate the distance from respondents' home address to their nearest park. The number of activity features (eg, playgrounds) in parks was determined objectively using the Community Park Audit Tool. RESULTS: Half of respondents were sufficiently active; 87.6% reported park use in the prior 6 months. Among sufficiently active respondents, 92.4% reported park use (P = .011). We found no difference in park proximity between respondents who did and did not report distance as a park use barrier. An objective assessment confirmed fewer activity features in parks near the homes of respondents reporting few activity features as a barrier to park use. The most often visited parks were significantly larger than the less-often visited parks. CONCLUSION: Parks might best support physical activity for families when activity features are carefully planned and equitably distributed across parks. Efforts to promote families' awareness of park locations might be warranted to reduce perceived proximity barriers.

Acute Effects of Plyometric and Resistance Training on Running Economy in Trained Runners.

Marcello, RT, Greer, BK, and Greer, AE. Acute effects of plyometric and resistance training on running economy in trained runners. J Strength Cond Res 31(9): 2432-2437, 2017-Results regarding the acute effects of plyometrics and resistance training (PRT) on running economy (RE) are conflicting. Eight male collegiate distance runners (21 ± 1 years, 62.5 ± 7.8 ml·kg·min V[Combining Dot Above]O2 peak) completed V[Combining Dot Above]O2 peak and 1 repetition maximum (1RM) testing. Seven days later, subjects completed a 12 minutes RE test at 60 and 80% V[Combining Dot Above]O2 peak, followed by a PRT protocol or a rested condition of equal duration (CON). The PRT protocol consisted of 3 sets of 5 repetitions at 85% 1RM for barbell squats, Romanian deadlifts, and barbell lunges; the same volume was used for resisted lateral lunges, box jumps, and depth jumps. Subjects completed another RE test immediately after the treatments and 24 hours later. Subjects followed an identical protocol 6 days later with condition assignment reversed. Running economy was determined by both relative V[Combining Dot Above]O2 (ml·kg·min) and energy expenditure (EE) (kcal·min). There was a significant (p ≤ 0.05) between-trial increase in V[Combining Dot Above]O2 (37.1 ± 4.2 ml·kg·min PRT vs. 35.5 ± 3.9 ml·kg·min CON) and EE (11.4 ± 1.3 kcal·min PRT vs. 11.0 ± 1.4 kcal·min CON) immediately after PRT at 60% V[Combining Dot Above]O2 peak, but no significant changes were observed at 80% V[Combining Dot Above]O2 peak. Respiratory exchange ratio was significantly (p ≤ 0.05) reduced 24 hours after PRT (0.93 ± 0.0) as compared to the CON trial (0.96 ± 0.0) at 80% V[Combining Dot Above]O2 peak. Results indicate that high-intensity PRT may acutely impair RE in aerobically trained individuals at a moderate running intensity, but that the attenuation lasts less than 24 hours in duration.

EPOC Comparison Between Isocaloric Bouts of Steady-State Aerobic, Intermittent Aerobic, and Resistance Training.

PURPOSE: Excess postexercise oxygen consumption (EPOC) is dependent on intensity, duration, and mode of exercise. The purpose of this study was to compare the effect of both exercise mode and intensity on EPOC while controlling for caloric expenditure and duration. METHOD: Ten low to moderately physically active men (22 ± 2 yrs) performed 3 nonrandomized isocaloric bouts of exercise separated by 7 days. The 1st session was resistance training (RT), followed by moderate-intensity steady-state (SS) aerobic exercise, and concluding with a high-intensity intermittent (IT) aerobic session. RESULTS: Total energy expenditure, rate of energy expenditure, and duration did not differ among trials (p>.05). Respiratory exchange ratio was greater during the RT trial than the SS trial (p < .05). At 12 hr postexercise, resting metabolic rate (RMR) was higher after the RT trial (4.7 ± 0.67 mL/kg/min) and IT trial (4.6 ± 0.62 mL/kg/min) compared with their respective baseline measurements (p < .008) and the SS trial (4.3 ± 0.58 mL/kg/min; p < .008). At 21 hr postexercise, RMR was higher after the RT trial (3.7 ± 0.51 mL/kg/min) and IT trial (3.5 ± 0.39 mL/kg/min) compared with the SS trial (3.2 ± 0.38 mL/kg/min; p < .008). The SS trial did not influence RMR at either 12 hr or 21 hr postexercise. CONCLUSION: Both RT and IT aerobic work increased EPOC to a greater degree than did SS work, indicating that either mode may be more effective at increasing total daily caloric expenditure than SS aerobic exercise.