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 05) than the RI-1 session. Postexercise MVC for the RI-3 session showed significantly greater reductions (-7.8%; p ≤ 0.05) compared with the RI-1 and control sessions. No significant changes in postexercise iEMG activity of the VL and VM were shown for any of the sessions (all p > 0.05). The findings of this study suggest that different RIs between sets lead to different acute neuromuscular responses. The longer RI seemed to induce higher neuromuscular fatigue, likely due to higher total volume and time under tension. Thus, longer RI may be a strategy that possibly would lead to greater long-term gains in muscle strength and hypertrophy of the lower limbs in trained older women.Kiely, M, Warrington, GD, McGoldrick, A, Pugh, J, and Cullen, S. Physiological demands of professional flat and jump horse racing. J Strength Cond Res 34(8) 2173-2177, 2020-No information is currently available on the effect of race distance on the physiological demands of jockeys. This study aimed to quantify the respective demands of short and long flat and jump race distances. Twenty professional jockeys (10 flat and 10 jump) participated in the study. The subjects initially performed a graded incremental exercise test to volitional exhaustion on a treadmill to determine the peak heart rate (HR) and blood lactate concentrations. Two competitive races (short and long) were then monitored on 2 separate occasions for each jockey type to obtain hydration, HR, blood lactate concentration, and rating of perceived exertion data. Mean distances for the 4 races were 1,247.2 ± 184.7 m (short flat race), 2,313.4 ± 142.2 m (long flat race), 3,480.2 ± 355.3 m (short jump race), and 4,546.4 ± 194.3 m (long jump race). The mean HR for the long flat race was 151 ± 19 b·min (79 ± 11% of HRpeak), which was significantly lower than all other race distances (p = 0.000, effect size [ES] = 0.469). A longer jump race resulted in a significantly higher reported rate of perceived exertion (RPE) (14 ± 2.8) than the short jump race (11.0 ± 1.5) (p = 0.009, ES = 0.271), whereas no significant difference was revealed between peak HR responses or blood lactate concentrations when comparing other race distances (p less then 0.05). The finding of this study supports previous limited research, which suggests that horse racing is a high-intensity sport, whereas RPE and mean HR fluctuate according to the race distance.Bottollier, V, Coulmy, N, Le Quellec, L, and Prioux, J. Energy demands in well-trained alpine ski racers during different duration of slalom and giant slalom runs. J Strength Cond Res 34(8) 2156-2164, 2020-The purpose of this study was to investigate the energy demands of different duration slalom (SL) and giant slalom (GS) events in well-trained alpine ski racers. Eight well-trained alpine ski racers (age 18.2 ± 0.8 years; stature 1.72 ± 0.10 m; body mass 65.8 ± 12.0 kg) performed an incremental laboratory test on cycle ergometer and 4 standardized alpine ski runs short (ST) and long (LG) versions of SL and GS (SLST, SLLG, GSST, and GSLG). Oxygen uptake (V[Combining Dot Above]O2) and heart rate (HR) were recorded continuously in all conditions. Blood lactate ([La]) was determined immediately before run and 3 and 5 minutes after run ([La]peak). The contribution of aerobic, glycolytic, and phosphagen energy systems was estimated. The aerobic system was the primary energy system involved in GSST (43.9 ± 5.7%) and GSLG (48.5 ± 2.5%). No significant difference in the contribution of aerobic and glycolytic systems was observed in SLST and SLLG. [La]peak was higher in SLLG (11.10 ± 2.41 mmol·L) than in GSST (8.01 ± 2.01 mmol·L). There was no difference in oxygen uptake peak between GSST and GSLG. Energetic training goals should focus on the improvement of both aerobic, glycolytic, and phosphagen systems for alpine ski racers who perform SL and GS. Giant slalom specialists might benefit from emphasizing the improvement of the aerobic system, without neglecting other systems.Rodríguez-Fernández, A, Villa, JG, Sánchez-Sánchez, J, and Rodríguez-Marroyo, JA. Effectiveness of a generic vs. specific program training to prevent the short-term detraining on repeated-sprint ability of youth soccer players.  https://www.selleckchem.com/products/ins018-055-ism001-055.html  J Strength Cond Res 34(8) 2128-2135, 2020-The aim of this study was to analyze the effects of 2 short-term training programs to prevent the negative effect of detraining on repeated-sprint ability (RSA) performance. The study was performed during a 2-week midseason break without official matches. Forty-five youth soccer players (17.7 ± 0.8 years, 175.4 ± 5.5 cm, and 67.2 ± 5.1 kg) were split into 3 groups during the intervention period inactivity group (IN; N = 16), generic high-intensity training group (GG; N = 15), and specific training group (SG; N = 14). IN was instructed to avoid performing physical activity during the 2-week training intervention. However, GG and SG performed 8 training sessions. GG performed a generic aerobic interval training consisting of 4 repetitions of 4 minutes of exercise at 90-95% of maximal heart rate. SG performed a specific conditioning through small-sided games (4 vs. 4, 4 × 4-minute) and repeated sprints (6 × 30-m). Testing sessions included an RSA test and a Yo-Yo intermittent recovery test level 1 (YYIR1). Repeated-sprint ability performance only improved after the training intervention in SG (∼2%, p less then 0.01, (Equation is included in full-text article.)= 0.23-0.25). Both GG and IN declined their performance in post-test (∼2%, p less then 0.01, (Equation is included in full-text article.)= 0.19-0.22). No significant effect, group × time, was analyzed for YYIR1 performance.  https://www.selleckchem.com/products/ins018-055-ism001-055.html  This study suggests that only specific training, based on small-sided games and repeated sprints, leads to short-term improvements on RSA performance in youth soccer players.West, JT, Miller, WM, Jeon, S, and Ye, X. The effects of a preconditioning rolling session on subsequent eccentric exercise-induced muscle damage. J Strength Cond Res 34(8) 2112-2119, 2020-The aim of this study was to examine the effects of a preexercise unilateral quadriceps muscle rolling intervention on subsequent ipsilateral (IPSI) or contralateral (CTRA) knee extension eccentric exercise-induced muscle damage. Twenty-seven healthy volunteers (14 men) underwent an eccentric exercise protocol (6 sets of 10 repetitions with 75% of the maximal isometric strength) with a single-leg knee extension machine. Before the eccentric exercise, the subjects were randomly assigned to either (a) IPSI group rolling the ipsilateral knee extensor muscles, (b) CTRA rolling the contralateral muscles, or (c) Control sitting for 6 minutes (same duration as the rolling intervention protocol) relaxed. The muscle soreness, passive knee extension range of motion, and knee extension isometric strength were measured before, immediately, 24 hours, and 48 hours after exercise.