Background: The study explored the influence of repeated drop jumps (DJs) from different drop heights on the lower extremity bilateral asymmetry and muscle activation of countermovement jumps (CMJs). Methods: Eighteen male athletes performed 200 drop jumps (DJs200) from three drop jump height (DJH30, 40 and 50 cm). The CMJs were performed before the first DJ and after the 50th, 100th, 150th and 200th DJs, recording them as pre-CMJ, CMJs50, CMJs100, CMJs150 and CMJs200. One-way repeated measures ANOVA was used to compare differences among the three drop heights at pre-CMJ, CMJs50, CMJs100, CMJs150 and CMJs200, respectively. Results: The peak ground reaction forces (PGRF) of CMJs100, CMJs150 and CMJs200 at DJH50 were greater than at DJH30 and DJH40 (all p < 0.05). The muscle activation during CMJs50 at DJH50 was greater than at DJH30 and DJH40 (all p < 0.05). The muscle activation during CMJs100, CMJs150 and CMJs200 at DJH50 was smaller than at DJH40 and DJH30 (all p < 0.05). The PGRF had no significant difference among the three different drop heights during CMJs50 (p > 0.05). Conclusions: The DJs50 at DJH50 had no effect on the bilateral asymmetry and increased muscle activation of CMJs. The excessive DJs100 at DJH50 increased bilateral asymmetry and decreased CMJ muscle activation during CMJs.

This study investigated the effect of wearing a typical surgical mask (SM) or a three-dimensional (3D) SM (3DSM) during whole-body, high-intensity, short-rest resistance exercise on cardiorespiratory, respiratory, and perceptual comfort responses in weightlifters. Twenty elite weightlifters (6 women and 14 men; age = 24.1 ± 4.9 years; height: 167.45 ± 7.60 cm; body mass = 76.48 ± 19.86 kg) who participated in this study performed 3 resistance exercise sessions in a randomized order: (1) without a mask (NM), (2) while wearing a typical SM, and (3) while wearing a 3DSM. Resistance exercise consisted of a descending pyramid scheme starting at 10 repetitions, with a decrease of one repetition per set for the back squat, bench press, and deadlift, as fast as possible at 75% of the one-repetition maximum. Cardiorespiratory and pulmonary function and comfort were measured. Across all conditions, effective postexercise hypotension (PEH) was noted in terms of decreased systolic blood pressure (−4.64%), diastolic BP (−5.36%), mean arterial pressure (−5.02%), and ankle–brachial index (−6.84%). However, the heart rate (40.34%) and rate of pressure product (33.60%) increased, and no effects on pulmonary function were observed in the three conditions. The participants reported higher breathing resistance and tightness when wearing a typical SM than when wearing a 3DSM or no mask. Therefore, both wearing and not wearing a face mask during whole-body, high-intensity, short-rest resistance exercise promoted PEH and exerted no detrimental effect on pulmonary function. Coaches, trainers, and athletes should consider wearing a 3DSM during resistance exercise.

This study aimed to compare the effects of triple continuous jumping snatch (TCJS) intervention training on the technique and performance of novice lifters. Males ( n = 22; age = 19.7 ± 0.9 years; height = 173.7 ± 6.1 cm; body mass = 76.3 ± 11.8 kg) who had no training experience in weightlifting were randomly assigned to a control (CG; n = 11) or an experimental (EG; n = 11) group, and trained three times a week for 8 weeks. The CG was trained in the snatch, and EG intervened with TCJS. In the initial state, t-tests and Hedges’ effect sizes revealed significant and very large-to-nearly perfect differences ( p < 0.001, g = 6.39) for barbell velocity while the barbell made contact with the body and the maximal barbell acceleration after contact ( p < 0.001, g = 3.79) between CG and EG. Moreover, differences in the angle between the barbell and the shoulder prior to the turnover phase exhibited significant and moderate decreases in weeks 2, 6, and 8 (all p < 0.05, g = 0.63–0.98) by performing the snatch with the TCJS intervention. The TCJS not only impacts barbell velocity and acceleration immediately, but also reduces horizontal movement between the barbell and body. The results of this study demonstrated that the TCJS constitutes a superior training method for novice lifters to enhance the stability of techniques when compared with snatch.

Objective: This study used surface electromyography (sEMG) to evaluate rectus abdominis (RA) and erector spinae (ES) sEMG amplitude in resistance-trained women performing the snatch pull, inverted sit-up, and hyperextension, and to examine whether any snatch pull intensity produces sEMG amplitude equivalent to that of the specialized core exercises. Methods: Twenty female university students with at least three years of resistance training experience (age: 22.2 ± 5.3 years; height: 161.4 ± 7.2 cm; body mass: 61.5 ± 10.4 kg) performed all three exercises. Equivalence was assessed with paired TOST (±10% MVC bounds). Results: RA amplitude was highest during the inverted sit-up (57.66% MVC), significantly greater than the snatch pull at 100% 1RM (25.52%) and hyperextension (9.22%, p < 0.01). ES amplitude was highest during the snatch pull at 100% 1RM (135.96% MVC), significantly greater than the inverted sit-up (9.61%) and hyperextension (69.39%, p < 0.001), and increased with snatch pull intensity (11.14% MVC per 10% 1RM, p < 0.001; marginal R ² = 0.168). None of the snatch pull intensities produced RA amplitude equivalent to the inverted sit-up, and none produced ES amplitude equivalent to that observed during hyperextension; with the 40% 1RM condition showing the smallest difference (−3.29% MVC, 90% CI −17.58 to 11.00). Conclusion: The snatch pull and the specialized core exercises produced distinct and non equivalent trunk muscle sEMG amplitude profiles. The snatch pull imposed high, load dependent ES demand but low RA demand, indicating that these exercises are complementary rather than interchangeable in weightlifting training.