Impact of Training Protocols on Lifting Velocity Recovery in Resistance Trained Males and Females

It has been suggested that sex differences exist in recovery following strength training. This study aimed to investigate the differences in recovery kinetics between resistance trained males and females following two different back squat (BSq) protocols. The first protocol (eight females and eight males) consisted of five sets of five repetitions at 80% of their one-repetition maximum (1RM) in the BSq (SMRT), while the second (seven females and eight males) consisted of five sets to muscular failure (MF) with a 4–6RM load (RMRT). The recovery was quantified with the mean concentric velocity (MV) at 80% of the 1RM immediately before and 5 min, 24, 48, and 72 h after the training protocol. Following the SMRT, a significant between-sex difference, favoring the females, was observed at 5 min, 24 h, and 48 h following the SMRT (p < 0.05, Effect Size (ES) = 1.01–2.25). Following the RMRT, only the males experienced a significant drop in performance after 5 min compared to the baseline (p = 0.025, ES = 1.34). However, no sex differences were observed at any timepoint (p > 0.05). These results suggest that males experienced more fatigue than females following a protocol where the volume relative to the 1RM was matched, while no differences in fatigue were evident following a protocol in which multiple sets were performed to MF.

Effects of velocity based training vs. traditional 1RM percentage-based training on improving strength, jump, linear sprint and change of direction speed performance: A Systematic review with meta-analysis

Background There has been a surge of interest on velocity-based training (VBT) in recent years. However, it remains unclear whether VBT is more effective in improving strength, jump, linear sprint and change of direction speed (CODs) than the traditional 1RM percentage-based training (PBT). Objectives To compare the training effects in VBT vs. PBT upon strength, jump, linear sprint and CODs performance. Data sources Web of science, PubMed and China National Knowledge Infrastructure (CNKI). Study eligibility criteria The qualified studies for inclusion in the meta-analysis must have included a resistance training intervention that compared the effects of VBT and PBT on at least one measure of strength, jump, linear sprint and CODs with participants aged ≥16 yrs. and be written in English or Chinese. Methods The modified Pedro Scale was used to assess the risk of bias. Random-effects model was used to calculate the effects via the mean change and pre-SD (standard deviation). Mean difference (MD) or Standardized mean difference (SMD) was presented correspondently with 95% confidence interval (CI). Results Six studies met the inclusion criteria including a total of 124 participants aged 16 to 30 yrs. The differences of training effects between VBT and PBT were not significant in back squat 1RM (MD = 3.03kg; 95%CI: -3.55, 9.61; I2 = 0%) and load velocity 60%1RM (MD = 0.02m/s; 95%CI: -0.01,0.06; I2 = 0%), jump (SMD = 0.27; 95%CI: -0.15,0.7; I2 = 0%), linear sprint (MD = 0.01s; 95%CI: -0.06, 0.07; I2 = 0%), and CODs (SMD = 0.49; 95%CI: -0.14, 1.07; I2 = 0%). Conclusion Both VBT and PBT can enhance strength, jump, linear sprint and CODs performance effectively without significant group difference.

Association of Performance in Strength and Plyometric Tests with Change of Direction Performance in Young Female Team-Sport Athletes

The change of direction (COD) ability is a task-specific skill dependent on different factors such as the degree of the turn, which has led to differentiating CODs as more force- (>90°) or velocity-oriented (<90°). Considering force and velocity requirements is of importance when designing sport-specific training programs for enhancing COD performance. Thus, 25 female handball and soccer players participated in this study, which investigated the association between three different strength and plyometric exercises and force- and velocity-oriented COD performance. By utilizing the median split analysis, the participants were further divided into a fast (n = 8) and a slow (n = 8) COD group, to investigate differences in step kinematics between fast and slow performers. The correlational analysis revealed that the bilateral back squat and unilateral quarter squat were significantly associated with several force- and velocity-oriented COD performance (r = −0.46 to −0.64), while the association between plyometric and COD performance was limited (r < 0.44). The fast COD group revealed higher levels of strength, jump height, peak velocities, higher step frequencies, shorter ground contact times, and greater acceleration and braking power (d > 1.29, p < 0.03). It was concluded that the observed correlation between strength and COD performance might be due to stronger athletes being able to produce more workload in a shorter time, which was supported by the step kinematics.

Bilateral back squat strength is increased during a 3-week undulating resistance training program with and without variable resistance in DIII collegiate football players

Background Optimizing training adaptations is of the utmost importance for the strength and conditioning professional. The pre-season of any sport is particularly important to ensure preparedness of the athletes. In DIII Collegiate Football pre-season consists of approximately 3 weeks. The abbreviated time of the pre-season increases the importance of optimizing training using safe methods, including alternative loading strategies. The purpose of the current study was to determine if a 3-week variable resistance training VRT during an undulating (UL) resistance training program elicited a greater increase in back squat strength compared to traditional loading methods. Methods and Materials Forty DIII Football players (age range: 18–25 years) participated in a 3-week UL bilateral back squat (BBS) program. Both groups performed the BBS 3 times per week with a minimum of 24 hours between exercise sessions. The control group (C) (n = 20) (height = 182.3 + 5.1 cm, body mass: pre = 102.8 ± 17.7 kg, post = 104.1 ± 17.8 kg) used traditional loading methods (i.e., Olympic weights only) and the experimental group (E) (n = 20) (height = 180.7 ± 8.0 cm, body mass: pre = 100.3 ± 27.1 kg, post = 101.0 ± 27.7 kg) used traditional loading methods and variable resistance (i.e., resistance bands). The variable resistance accounted for approximately 20% of the total resistance while 80% of the resistance was supplied by traditional loading methods. Results When all data was pooled, subjects had a significant increase (p < 0.05) in 1-RM BBS from pre (154.2 + 26.1 kg) to post (166.8 + 26.2 kg), with a percent increase of 8.13% at the completion of the 3-week training program. There was no significant difference (p > 0.05) between the C and E groups for muscular strength, muscular power, or vertical jump. Volume-loads were not significantly (p > 0.05) different between groups for any of the weeks (C: Week 1 = 858.1 + 101.3, Week 2 = 588.6 + 69.2, Week 3 = 332.5 + 38.9, Total = 1179.2 + 209.4 vs. E: Week 1 = 835.2 + 179.7, Week 2 = 572.2 + 123.4, Week 3 = 323.5 + 68.8, Total = 1730.9 + 371.8) or for the pre-season as a whole. Conclusion A traditional UL resistance training program and training program with variable resistance are both effective methods at increasing back squat strength during 3 weeks of training. Resistance band variable resistance (VR) does not enhance training effects within a 3-week mesocycle greater than traditional resistance.

The Effects of Plyometric Conditioning Exercises on Volleyball Performance with Self-Selected Rest Intervals

Post-activation performance enhancement remains a topic of debate in sport science. The purpose of this study was to examine the effects of lower-body plyometric conditioning activity (CA) with a self-selected intra-complex rest interval on upper and lower-body volleyball specific performance. Eleven resistance-trained female volleyball players participated in the study (age: 20 ± 2 years; body mass: 67.8 ± 4.4 kg; height: 178 ± 6 cm; half back squat one-repetition maximum: 78.6 ± 10.2 kg; experience in resistance training: 5.5 ± 2.1 years and in volleyball training: 10 ± 2.3 years). Each participant performed a plyometric CA followed by two different sport-specific tests: an attack jump and a standing spike attack. The changes in jump height (JH), relative mean power output (MP) and ball velocity (BV) were analyzed before and after the CA with self-selected rest intervals. The applied plyometric CA with self-selected intra-complex rest intervals led to an insignificant decline in JH (p = 0.594; effect size [ES]: −0.27) and MP (p = 0.328; ES: −0.46) obtained during the attack jump as well as a significant decline in BV (p = 0.029; ES: −0.72) during the standing spike attack. This study showed that a plyometric CA with self-selected intra-complex rest intervals failed to elicit localized and non-localized PAPE effect in a group of sub-elite volleyball players.

Time course of recovery following CrossFit® Karen Benchmark Workout in trained men

The study describes the acute and delayed time course of recovery following the CrossFit&reg; Benchmark Workout Karen. Eight trained men (28.4&plusmn;6.4 years; 1RM back squat 139.1&plusmn;26.0 kg) undertook the Karen protocol. The protocol consists of 150 Wall Balls, aiming to hit a target 3 meters high. Countermovement jump height (CMJ), creatine kinase (CK), and perceived recovery status scale (PRS) (general, lower and upper limbs) were assessed pre, post-0h, 24h, 48h and 72h after the session. The CK concentration 24h after was higher than pre-exercise (338.4 U/L vs. 143.3 U/L; effect size: 0.74; p&le;0.05). At 48h and 72h following exercise, CK concentration had returned to baseline levels. The PRS general and of the lower limbs were lower in the 24-hours post-exercise compared to pre-exercise (PRS general: 4.7 &plusmn;1.5 and 7.9 &plusmn;1.7 mmol/L; and PRS of the lower limbs: 4.0 &plusmn;2.5 and 7.9 &plusmn;0.8, respectively). The PRS general, lower, and upper limbs were reduced at 48-post exercise compared to 72-hours post-exercise scores. Our findings provide insights into the fatigue profile and recovery in acute CrossFit&reg; and can be useful to coaches effectively design the daily session.

Effects of Stance Width and Barbell Placement on Kinematics, Kinetics, and Myoelectric Activity in Back Squats

Barbell placement and stance width both affect lifting performance in the back squat around the sticking region. However, little is known about how these squat conditions separately could affect the lifting performance. Therefore, this study investigated the effects of stance width and barbell placement upon kinematics, kinetics, and myoelectric activity around the sticking region during a three-repetition maximum back squat. Nine men and nine women (body mass: 76.2 ±11.1, age: 24.9 ± 2.6) performed back squats with four different techniques, such as: high-bar narrow stance (HBNS), high-bar wide stance, low-bar narrow stance, and low-bar wide stance where they lifted 99.2 ± 23.6, 92.9 ± 23.6, 102.5 ± 24.7, and 97.1 ± 25.6 kg, respectively. The main findings were that squatting with a low-bar wide stance condition resulted in larger hip contributions to the total moment than the other squat conditions, whereas squatting with an HBNS resulted in greater knee contributions to the total moment together with higher vastus lateralis and less gluteus maximus myoelectric activity. Our findings suggest that training with an HBNS could be beneficial when targeting the knee extensors and plantar flexors, whereas a low-bar wide stance could be beneficial when targeting the hip extensors.