Effects of different sprint training programs with ball on explosive, high-intensity and endurance-intensive performances in male young soccer players

This study compared the effects of different sprint ball-based training programs on fitness-related performances in youth soccer players. Forty male players (age: 15.2 ± 0.6 yrs) participated in a short-term (8 weeks) randomized parallel fully controlled training study, with pre-to-post measurements. Players were randomly assigned to 3 sprint ball-based training groups: training with combined sprint (performing linear and change of direction sprints; CST), or using linear sprint (LST), or performing sprint with change of direction (CODT) and to a control group (CONT). Pre- and post-training players completed a test battery involving linear sprinting (10 and 20 m, and flying 10 m), 505 test (COD), 15 m test with ball (CODB), countermovement jump test (CMJ test) and maximal oxygen consumption (VO2max). All physical performance’ variables improved after the training intervention (all p < 0.05; ES ≥ 0.2). No main effect of groups was observed in linear sprinting, CMJ and VO2max (p > 0.05; ES < 0.2). A training group main effect was found (p < 0.0001; ES = 0.50) for COD with CODT induced better performance than LST and CONT (all p <0.0001; ES > 0.8). Also, a training group main effect (p = 0.009; ES = 0.35) was found for CODB with CODT elicited better performance than LST and CONT (all p = 0.001; ES > 0.80). Our findings suggest that ball-based training programs were more effective to improve fitness levels in youth players during the in-season period and that CODT modality was more effective to improve COD and CODB performances.

The Effect of Differential Repeated Sprint Training on Physical Performance in Female Basketball Players: A Pilot Study

This pilot study aimed to determine the effects of differential learning in sprint running with and without changes of direction (COD) on physical performance parameters in female basketball players and to determine the feasibility of the training protocol. Nine female basketball players completed 4 weeks of repeated sprint training (RST) with (COD, n = 4) or without (NCOD, n = 5) changes of direction. A battery of sprints (0–10 and 0–25 m), vertical jumps (counter movement jump (CMJ), drop jump, and single-leg CMJs), and COD tests were conducted before and after intervention. NCOD completed two sets of ten sprints of 20 m, whereas COD performed 20 m sprints with a 180 degree turn at 10 m, returning to the starting line. Before each sprint, participants were instructed to provide different fluctuations (i.e., differential learning) in terms of varying the sprint. Both groups had 30 s of passive recovery between two sprints and 3 min between sets. A significant effect of time for the 0–10 m sprint, CMJ, and single leg-CMJ asymmetries were observed. Adding “erroneous” fluctuation during RST seems to be a suitable and feasible strategy for coaches to enhance physical performance in young female basketball players. However, further studies including larger samples and controlled designs are recommended to strengthen present findings.

Electromyography, Stiffness and Kinematics of Resisted Sprint Training in the Specialized SKILLRUN® Treadmill Using Different Load Conditions in Rugby Players

This study’s aim was to analyze muscle activation and kinematics of sled-pushing and resisted-parachute sprinting with three load conditions on an instrumentalized SKILLRUN® treadmill. Nine male amateur rugby union players (21.3 ± 4.3 years, 75.8 ± 10.2 kg, 176.6 ± 8.8 cm) performed a sled-push session consisting of three 15-m repetitions at 20%, 55% and 90% body mas and another resisted-parachute session using three different parachute sizes (XS, XL and 3XL). Sprinting kinematics and muscle activity of three lower-limb muscles (biceps femoris (BF), vastus lateralis (VL) and gastrocnemius medialis (GM)) were measured. A repeated-measures analysis of variance (RM-ANOVA) showed that higher loads during the sled-push increased (VL) (p ≤ 0.001) and (GM) (p ≤ 0.001) but not (BF) (p = 0.278) activity. Furthermore, it caused significant changes in sprinting kinematics, stiffness and joint angles. Resisted-parachute sprinting did not change kinematics or muscle activation, despite producing a significant overload (i.e., speed loss). In conclusion, increased sled-push loading caused disruptions in sprinting technique and altered lower-limb muscle activation patterns as opposed to the resisted-parachute. These findings might help practitioners determine the more adequate resisted sprint exercise and load according to the training objective (e.g., power production or speed performance).

Tent versus Mask-on Acute Effects during Repeated-Sprint Training in Normobaric Hypoxia and Normoxia

Repeated sprint in hypoxia (RSH) is used to improve supramaximal cycling capacity, but little is known about the potential differences between different systems for creating normobaric hypoxia, such as a chamber, tent, or mask. This study aimed to compare the environmental (carbon dioxide (CO2) and wet-globe bulb temperature (WGBT)), perceptual (pain, respiratory difficulty, and rate of perceived exertion (RPE)), and external (peak and mean power output) and internal (peak heart rate (HRpeak), muscle oxygen saturation (SmO2), arterial oxygen saturation (SpO2), blood lactate and glucose) workload acute effects of an RSH session when performed inside a tent versus using a mask. Twelve well-trained cyclists (age = 29 ± 9.8 years, VO2max = 70.3 ± 5.9 mL/kg/min) participated in this single-blind, randomized, crossover trial. Participants completed four sessions of three sets of five repetitions × 10 s:20 s (180 s rest between series) of all-out in different conditions: normoxia in a tent (RSNTent) and mask-on (RSNMask), and normobaric hypoxia in a tent (RSHTent) and mask-on (RSHMask). CO2 and WGBT levels increased steadily in all conditions (p < 0.01) and were lower when using a mask (RSNMask and RSHMask) than when inside a tent (RSHTent and RSNTent) (p < 0.01). RSHTent presented lower SpO2 than the other three conditions (p < 0.05), and hypoxic conditions presented lower SpO2 than normoxic ones (p < 0.05). HRpeak, RPE, blood lactate, and blood glucose increased throughout the training, as expected. RSH could lead to acute conditions such as hypoxemia, which may be exacerbated when using a tent to simulate hypoxia compared to a mask-based system.