Hunter, GR, Singh, H, Martins, C, Baranauskas, MN, and Carter, SJ. Stretch-shortening cycle potentiation and resistance training-induced changes in walking economy/ease and activity-related energy expenditure in older women. J Strength Cond Res 35(5) 1345-1349, 2021-Use of elastic energy to improve economy and ease of walking may be important for older adults. The purpose of this investigation was to determine whether baseline (i.e., untrained) stretch-shortening cycle potentiation (SSCP) was associated with potential changes in free-living activity-related energy expenditure (AEE) after supervised exercise training. Sedentary, postmenopausal women (n = 64) between 60 and 74 years of age were evaluated before and after 16 weeks of combined aerobic and resistance training. Assessments included (a) body composition (dual-energy X-ray absorptiometry), (b) resting energy expenditure (indirect calorimetry), (c) submaximal and maximal walking (treadmill/indirect calorimetry), (d) total energy expenditure (doubly . Results indicated that baseline SSCP was related (r = -0.29; p less then 0.02) to changes in AEE. However, subjects who possessed a high baseline SSCP did not increase SSCP or AEE, whereas subjects with low to moderate baseline SSCP demonstrated a significant increase in both SSCP (low +0.54 and moderate +0.47 m·s-1) and AEE (low +158 and moderate +333 kcal·d-1) post-training (all p less than 0.05). Our findings suggest that among subjects with low to moderate baseline SSCP, 16 weeks of combined aerobic and resistance training can increase SSCP and free-living AEE. However, subjects with high baseline SSCP may require tailored exercise to increase SSCP and possibly AEE.

Wong, R, Laudner, K, Evans, D, Miller, L, Blank, T, and Meister, K. Relationships between clinically measured upper-extremity physical characteristics and ball spin rate in professional baseball pitchers. J Strength Cond Res 35(5) 1331-1337, 2021-During baseball pitching, physical characteristics of the shoulder, elbow, wrist, hand, and fingers have been hypothesized to be critical to creating ball spin. The purpose of this study was to determine if pitchers with greater shoulder, elbow, wrist, and finger range of motion (ROM), arm and hand length, wrist strength, or grip and finger strength would produce greater ball spin than those with less physical characteristics. Ninety, asymptomatic, professional baseball pitchers participated (age = 24.5 ± 3.9 years; height = 189.9 ± 6.1 cm; body mass = 92.6 ± 10.6 kg). Goniometers and a digital level were used to measure shoulder, elbow, wrist, and finger ROM, a tape measure was used to assess arm and hand lengths, and handheld dynamometers were used to measure wri a 3-dimensional Doppler radar and video system. Standard multiple regression analyses showed no significant relationships existed between ball spin and any of the upper-extremity ROM or limb length variables (R2 = 0.01-0.03; p = 0.40-0.94). However, there was a significant relationship for the summation of wrist strength (R2 = 0.24, p = 0.03). Both time to wrist extension strength B = 0.50 (95% confidence interval [CI] 0.23-0.76), p = 0.001 and radial deviation strength (B = 0.41 [95% CI 0.15-0.66], p = 0.002) were significant predictors within this model. These results demonstrate that the rate of ball spin during a pitch may be partially altered by increasing wrist extension acceleration and radial deviation strength. However, the subsequent clinical measurements of shoulder, elbow, wrist, and finger ROM, arm and hand length, and grip and finger strength were not associated with ball spin.

Davis, JK, Wolfe, AS, Basham, SA, Freese, EC, and De Chavez, PJD. Neuromuscular, endocrine, and perceptual recovery after a youth American football game. J Strength Cond Res 35(5) 1317-1325, 2021-American football is a high-intensity intermittent sport consisting of various movements and repeated collisions which highlights the importance of adequate recovery from a game to prepare for the next competition. Therefore, the purpose of this study was to determine the time course of recovery markers after a youth American football game. Thirteen male American football youth players were monitored for 7 days after a single football game. Baseline measures were taken 28 hours pregame for lower-body neuromuscular function by countermovement jumps (CMJs) to determine peak power (PP), jump height (JH), flight time (FT), and takeoff velocity (TOV). Saliva was analyzed for cortisol, testosterone, and C-reactive protein (CRP). Perceptual recovery was assessed by the modified profile of mood states (POMS), perceived rected immediately postgame (30 minutes) and at 20, 44, 68, 92, 116, and 140 hours postgame. Compared with baseline values, there was a significant decrease (p less then 0.05) in CMJ PP, JH, and TOV up to 68 hours postgame and FT 44 hours postgame. No significant difference existed among time points for salivary testosterone and CRP. selleck Cortisol levels significantly increased postgame compared with baseline (p less then 0.05). Total mood disturbance, assessed by POMS, and daily wellness markers for energy were significantly decreased (p less then 0.05), whereas daily wellness markers for soreness were significantly increased (p less then 0.05) immediately after the game. Players exhibited a significant decrease in PRS up to 44 hours postgame (p less then 0.05), similar to the decrease in neuromuscular function. Neuromuscular function and PRS are impaired for up to 44-68 h postgame.

Boone, JB, VanDusseldorp, TA, Feito, Y, and Mangine, GT. Relationships between sprinting, broad jump, and vertical jump kinetics are limited in elite, collegiate football athletes. J Strength Cond Res 35(5) 1306-1316, 2021-To evaluate the relationships and agreement in kinetics measured during a 10-yd sprint, a standing broad jump (SBJ), and a vertical jump (VJ), 73 collegiate football players (22.3 ± 0.8 years, 188 ± 7 cm, 113 ± 23 kg) volunteered for this cross-sectional study over a 3-year period. At the beginning of each athlete’s off-season training phase and after a standard warm-up, each athlete completed 2-3 maximal trials of each test while tethered to a robotic, cable-resistance device (10-yd sprint and SBJ) or a linear position transducer (VJ alone). Force (N), velocity (m·s-1), and power (W) were measured during the first 2 steps, acceleration phase (units·step-1), and entire 10-yd sprint, and the entire SBJ and VJ. Spearman and partial correlations (controlling for stature) revealed small-to-moderate relationships (r = -0.