Immediate Effects of Different Trunk Exercise Programs on Jump Performance

Effect of post-activation potentiation using core activation on isometric core strength and countermovement jump variables in university male recreational athletes

Core strengthening exercises have been integrated into the conditioning regimens of sportsmen of all levels. Despite a wealth of evidence, the question of what influence core stability exercises have on jump performance remains unsolved. Only a small percentage of studies have explored effects of standalone core training. The objective of this research was to explore acute changes in countermovement jump (CMJ) performance caused by post-activation potentiation (PAP) adopting core activation exercises. 25 male recreational athletes were recruited as participants. They visited on three occasions-first for familiarisation, following for baseline data using a conventional warmup, and final for repeat data upon inducing PAP. Isometric dynamometer was used to quantify core isometric strength and CMJ variables were evaluated using a Portable performance analysis system with MARS Software. Paired t-test and multivariate analysis were carried out. All core strength metrics reported marked increase at P<0.001 from conventional to PAP warmup. Following CMJ metrics varied significantly: jump height from take-off (P<0.001), jump height from flight (P<0.01), flight time (P<0.01,) and force at free-fall (P<0.001). Core training with PAP is a form of neuromuscular training that has the potential to improve power, agility, and speed by modifying force absorption, active joint stabilisation, and improved movement patterns. These alterations are ascribed to changes in cerebral drive, as well as enhanced motor-unit activation and firing frequency at the muscle level. Before a competition, a core activation warm-up can offer a unique training stimulus and increase performance via an ergogenic response. The core is essential for optimal athletic performance and should not be overlooked.

Immediate Effects of Stabilization Exercises on Trunk Muscle Activity during Jump Header Shooting: A Pilot Study

This study aimed to clarify trunk muscle activity during jump header shooting and examine the immediate effects of trunk stabilization exercises on trunk muscle activity. Nineteen males who had played soccer for over 5 years were assigned to either the trunk stabilization exercise group or the control group. Muscle activity during jump header shooting was measured before and after intervention. The intervention in the trunk stabilization exercise group was trunk muscle training, whereas that in the control group was sitting. The phases of jump header shooting and the effects of the interventions were compared. In pre-intervention measurements, the internal oblique activity during the push-off phase and early floating phase was significantly greater than that during the late floating phase (p < 0.01667). In pre-intervention measurements, the muscle activity of the internal oblique increased from the push-off phase, prior to the increase in muscle activity of the rectus abdominis and external oblique, whereas the muscle activity of all abdominal muscles increased immediately after take-off. The trunk stabilization exercise intervention decreased the muscle activity of the erector spinae (p < 0.05). There seems to be a certain activation sequence in the abdominals during jump header shooting, and a single application of stabilization exercises could possibly reduce the activation of the back muscles.

Changes in the awareness and understanding of trunk muscle training in high school athletes

[Purpose] This study aimed to compare the results of two questionnaires administered in 2013 and 2020, on the level of awareness and understanding of trunk muscle training. [Participants and Methods] In total, 238 soccer club members in high schools responded to our questionnaire regarding trunk muscle training. Two teams were recruited from the top (top 4), middle (top 16), and bottom levels (first-round losers), according to the prefectural tournament's results in 2019. This questionnaire comprised questions divided into four parts: 1. Prevalence of trunk muscle training; 2. Knowledge of the classification of trunk muscles (local and global); 3. Consciousness of local and global muscles during trunk muscle training; and 4. Knowledge of the role of each muscle. These results were compared to those obtained from the survey in 2013. [Results] A significant difference was observed only in the responses to question 2. Regarding question 2 in 2020, several student-athletes in the top-level teams were aware of muscle classification compared to those in the middle- and lower-level teams. [Conclusion] The number of athletes who understood the classification of trunk muscles increased significantly in 2020. Therefore, in the future, we would need to better educate young athletes concerning the purpose of trunk muscle training and the role of each muscle.

Effects of a Specific Core Stability Program on the Sprint and Change-of-Direction Maneuverability Performance in Youth, Male Soccer Players

Although it is recommended to use sport-specific training programs to optimize performance, studies analyzing the effects of the core stability training with high levels of sport-specificity on athletic performance are insufficient and unclear. The objective of this study was to analyze the effects of the level of specificity of a CORE stability program on specific soccer actions. Fourteen youth players were randomly assigned to the specific core stability group (SCS; n = 7) or the general core stability group (GCS; n = 7). The eight-week intervention consisted of two weekly training sessions added to the usual soccer training. Both groups performed four CORE stability tasks. The SCS group followed the principle of sports specificity, while the GCS group performed CORE stability commons. Ten-meter linear sprinting (Sprint) and change-of-direction maneuverability (V-cut) were evaluated before and after the intervention programs. A statistically significant improvement was obtained in Sprint (d = 0.84 95% CI (0.22, 1.45), p = 0.008) and V-cut (d = 1.24 95% CI (0.52, 1.93), p < 0.001). At posttest, statistically nonsignificant differences were obtained between groups in Sprint (d = 1.03 95% CI (−0.25, 2.30), p = 0.082) and V-cut (d = −0.56 95% CI (−1.89, 0.78), p = 0.370). In conclusion, sprint and change-of-direction maneuverability were improved, but there was no superiority of any type of training.

Acute Effects of Vibration Foam Rolling Warm-Up on Jump and Flexibility Asymmetry, Agility and Frequency Speed of Kick Test Performance in Taekwondo Athletes

The effect of asymmetry on flexibility and jump in taekwondo athletes and the influence of vibration foam rolling on asymmetry and frequency speed of kick test has not been examined. This study examined the effects of three warm-up protocols on subsequent sports performance in elite male taekwondo athletes. Fifteen elite male taekwondo athletes (20.63 ± 1.18 years) completed three warm-up protocols in a randomized order: general warm-up [GW], GW with vibration foam rolling [GW + VR], and GW with double VR for the weaker leg [GW + double VR]), was delivered before the subsequent tests: flexibility, single-leg countermovement jump (CMJ), 505 agility, hexagon test, and multiple frequency speed of kick tests (FSKTs). Relative to GW, the GW + VR significantly improved the hexagon test (GW + VR = 11.60 ± 1.01 s; GW = 12.80 ± 1.58 s). In addition, the GW + VR and GW + double VR yielded greater kick numbers in FSKT 5 (GW + VR = 21.13 ± 1.96 reps; GW + double VR = 20.93 ± 1.67 reps; GW = 19.27 ± 1.62 reps) and a higher kick decrement index (GW + VR = 5.45 ± 2.57%; GW + double VR = 5.88 ± 3.22%; GW = 9.54 ± 5.00%). However, the GW + VR and GW + double VR did not significantly improve the flexibility and CMJ asymmetry performance. The GW + VR is more beneficial for warming up than the GW is among male collegiate taekwondo athletes.

Efficacy of downhill running training for improving muscular and aerobic performances

This study investigated effects of downhill (DR) versus level (LR) running training on various muscular and aerobic performances. Eighteen healthy young males conducted either DR (DR group (DRG), n = 10: -10% slope) or LR (LR group (LRG), n = 8) training at a target heart rate (HR) associated with lactate threshold (LT) for 20 min·session^-1, 3 sessions·week^-1, for 5 weeks. Before and after the interventions, the following variables were measured: knee extension torque (-150, -30, 0, 30, 150°·s^-1), leg extension power (simultaneous hip and knee extension: 0.8 m·s^-1), squat and countermovement jump height, rebound jump index (jump height·contact time^-1), 20-m linear sprint and change-of-direction (Pro-agility and V-cut tests) time, and aerobic capacity (maximal oxygen uptake, energy cost at LT, and velocity at maximal oxygen uptake and LT) on a level surface. Throughout the training sessions, HR during running did not differ between the groups (DRG: 77.7% ± 4.6% vs LRG: 76.4% ± 4.6% of maximal HR; average across all sessions), while velocity was significantly higher for DRG (14.5 ± 1.1 vs 12.0 ± 1.9 km·h^-1). After the training, DRG significantly improved knee extension torque at all angular velocities (9%-24%) and change-of-direction time for both tests (2%-3%), with no changes in other parameters. LRG significantly improved maximal oxygen uptake (5%), energy cost at LT (3%), and velocity at maximal oxygen uptake (7%), without changes in others. These results suggest that DR training has a greater potential to improve the knee extension strength and change-of-direction ability, but has little effect on the aerobic capacity, compared with HR-matched LR training.