Effects of bouncing the barbell in bench press on throwing velocity and strength among handball players

Bench press is a popular training-exercise in throw related sports such as javelin, baseball and handball. Athletes in these sports often use bouncing (i.e., letting the barbell collide with the chest) to create an increased momentum to accelerate the barbell upwards before completing the movement by throwing the barbell. Importantly, the effects of the bouncing technique in bench press have not been examined. Therefore, the aim of this study was to compare the effects of bench press throw with (BPTbounce) or without bounce (BPT) on throwing velocity (penalty and 3-step), 1-repetition maximum (1-RM) and average power output (20-60kg) in bench press among handball players. Sixteen male amateur handball players (7.1±1.9 years of handball experience) were randomly allocated to an eight-week supplementary power training program (2 x week-1) with either the BPT or BPTbounce. Except for the bounce technique, the training programs were identical and consisted of 3 sets with 3–5 repetitions at 40–60% of 1-RM with maximal effort in free-weight barbell bench press throw. The results revealed no significant differences between the groups in any of the tests (p = 0.109–0.957). However, both groups improved penalty throw (BPT; 4.6%, p<0.001, ES = 0.57; BPTbounce; 5.1%, p = 0.008, ES = 0.91) and 1-RM (BPT; 9.7%, p<0.001, ES = 0.49; BPTbounce; 8.7%, p = 0.018, ES = 0.60), but only the BPT improved the 3-step throw (BPT; 2.9%, p = 0.060, ES = 0.38; BPTbounce; 2.3%, p = 0.216, ES = 0.40). The BPT improved power output only at 20kg and 30kg loads (9.1% and 12.7%; p = 0.018–0.048, ES = 0.43–0.51) whereas BPTbounce demonstrated no significant differences across the loads (p = 0.252–0.806). In conclusion, the bounce technique demonstrated similar effects on throwing velocity, muscle strength and muscle power output as conventional bench press throw without the bounce technique.

The Effects of Hydrogen Supplement on Cycling Performance During Aerobic and Anaerobic Exercise in Humans: A Pilot Study

Objectives In this study we investigated the effects of hydrogen (H2) supplement, in the form of calcium bound H2 powder capsules, on aerobic and anaerobic cycling exercise. Methods Trained male subjects participated in a randomized, double-blind, crossover design trial and received H2-rich calcium powder (HCP) supplement (1500 mg/day, 2.544 μg/day of H2 gas) or H2-depleted placebo (PLA) (1500 mg/day) for 3 consecutive days. Aerobic experiment: Eighteen subjects carried out a cycling incremental exercise starting at 20 watts (W) work rate, and increasing by 20 W/2 minutes until exhaustion. Blood gases including pH, bicarbonate ion (HCO3−), partial pressures of CO2 (PCO2), metabolic profile including lactate (Lac), and electrolytes including chloride (Cl−) were measured at rest and at 120-, 200-, and 240-W work rates. Anaerobic experiment: Six subjects carried out a 30 second Wingate anaerobic exercise test (WAnT) bout with a resistive load of 7.5% of body mass. Lac was then measured at 1-, 3-, 5-, and 15-minutes following the WAnT exercise. Results Aerobic experiment: At rest, HCP had a significantly lower pH (P = 0.048), Cl− (P = 0.011), and a higher HCO3− (P = 0.041), PCO2 (P = 0.026) compared to the PLA group. During exercise, pH decrease (supplement effect: P = 0.043) and the HCO3− increase (supplement effect: P = 0.030) continued in the HCP group. Additionally, HCP did not affect peak work load and exercise duration. And no changes were noted in Lac at rest or during exercise. Anaerobic experiment: HCP did not affect peak power output or Lac recovery following WAnT. However the average power output during exercise was significantly higher in the HCP group (P = 0.019) compared to the PLA group. Conclusions HCP supplementation following 3 days of intake, slightly lowered pH during aerobic exercise, and increased average power output in the anaerobic WAnT exercise compared to the PLA group. HCP supplement might have an ergogenic effect in an anaerobic exercise setting. Funding Sources This study was supported by The Japan Society for the Promotion of Science, and the Ministry of Education, Science, and Culture of Japan. In addition, we received a research grant from the company ENAGEGATE Inc. and they provided the HCP supplement and placebo. However, no intercession, restrictions or agreements of any kind was imposed between parties regarding research design, results or publications.

The effect of citrus flavonoid extract supplementation on anaerobic capacity in moderately trained athletes: a randomized controlled trial

Background Nutritional supplementation is commonly used by athletes to improve their exercise performance. Previous studies demonstrated that citrus flavonoid extract (CFE) supplementation may be an effective strategy to improve exercise performance in male athletes. Yet, no conclusive research has been performed to investigate the effect of chronic CFE supplementation on high-intensity exercise performance under anaerobic conditions. Therefore, the aim of the study was to assess whether CFE supplementation in daily dosages of 400 and 500 mg for a period of 4 and 8 weeks improves anaerobic exercise capacity. Methods A randomized, double-blind, placebo controlled, parallel clinical study was conducted in 92 moderately trained healthy men and women. Subjects were randomized to receive 400 mg of CFE (n = 30), 500 mg of CFE (n = 31) or placebo (n = 31) daily, for 8 consecutive weeks. The Wingate anaerobic test was used to assess anaerobic exercise capacity and power output at baseline, after 4 weeks and after 8 weeks. Results After 4 weeks supplementation, average power output significantly increased in the 400 mg group (Estimated difference [ED] = 38.2 W [18.0, 58.3]; p < 0.001; effect size [ES] = 0.27) and in the 500 mg group (ED = 21.2 W [0.91, 41.4]; p = 0.041; ES = 0.15) compared to placebo. The 5 s peak power output was also increased in the 400 mg group (ED = 53.6 [9.96, 97.2]; p = 0.017; ES = 0.25) after 4 weeks compared to placebo. After 8 weeks of supplementation, average power output was significantly improved in the group receiving 400 mg of CFE (ED = 31.6 [8.33, 54.8]; p = 0.008; ES = 0.22) compared to placebo. Conclusion These results demonstrate that CFE supplementation improved anaerobic capacity and peak power during high intensity exercise in moderately trained individuals. Further research is needed to identify the underlying mechanisms that are affected by CFE supplementation. Trial registration ClinicalTrials.gov (NCT03044444). Registered 7 February 2017

Physiological response to eccentric and concentric cycling in patients with chronic obstructive pulmonary disease

We aimed to compare the cardiorespiratory, metabolic, and perceptual responses to high- and moderate-intensity eccentric cycling versus moderate-intensity concentric cycling in chronic obstructive pulmonary disease (COPD) patients. Ten patients with moderate COPD (forced expiratory volume in 1 s (FEV1) = 68.6% ± 20.4% of predicted; 68.3 ± 9.1 years) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum workload; Wmax), moderate-intensity eccentric (ECC-M: 50% Wmax), and high-intensity eccentric (ECC-H: 100% Wmax) cycling. Average power output, oxygen consumption (V̇O2), minute ventilation (VE), respiratory frequency (fR), oxygen saturation (SpO2), heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), rate of perceived exertion (RPE), and dyspnea were measured during cycling. Compared with CONC-M, lower V̇O2 (–52% ± 14%), VE (–47% ± 16%), fR (–21% ± 14%), HR (–14% ± 16%), SBP (–73% ± 54%), RPE (–36% ± 26%), and dyspnea (–41% ± 37%) were found during ECC-M. During ECC-H, a similar metabolic demand to CONC-M was found. However, average power output was 117% ± 79% higher during ECC-H. Eccentric cycling can be safely performed by COPD patients and induced lower cardiorespiratory, metabolic, and perceptual responses than concentric exercise when performed at the same workload. Novelty Moderate- and high-intensity eccentric cycling can be performed by COPD patients. Moderate-intensity eccentric cycling showed lower cardiorespiratory, metabolic, and perceptual demand than concentric cycling at the same workload in COPD patients. Even at double workload, eccentric cycling induces lower cardiorespiratory, metabolic, and perceptual demand than moderate-intensity concentric cycling.

CORRELATION ANALYSIS OF OLYMPIC-STYLE WEIGHTLIFTING EXERCISES AND VERTICAL JUMPS

ABSTRACTPURPOSE Many types of vertical jumps (VJ) are commonly used to assess the development of the level of explosive strength of lower limbs achieved after a training period. This study is focused on comparing various parameters of different types of VJ with 1 RM in Olympic-style weightlifting, squat and deadlift with an Olympic bar.METHODS Twelve elite weightlifters (men=8; women=4; age 26±4 years, height = 173±8 cm; weight 93±23 kg; weight category from 64 kg to +109 kg) were tested for 1 RM in the following exercises: snatch, clean and jerk, deadlift, squat and variations of VJ on dynamometric plates (Kistler Force Plate). The variations of VJ were: squat jump with the arm swing (SJA) and non-arm swing (SJ), countermovement jump with the arm swing (CMJA) and non-arm swing (CMJ). The parameters compared for each type of VJ were: jump height (m), relative force (% of body weight), relative power (W/kg of body weight) and average power (W). For statistical analysis, the parametric Pearsons correlation coefficient with α=0.05 was used. RESULTS The results show a significant correlation between 1 RM in exercises with an Olympic bar (snatch, clean and jerk, back squat and deadlift) and the CMJ, CMJA, SJ and SJA only in the average power output (W) parameter (p<0.05). The significant correlation coefficients in the average power output (W) were for the CMJA and the snatch r=0.96 r2= 0.92, clean and jerk r=0.96 r2= 0.92, back squat r=0.97 r2= 0.94 and deadlift r=0.93 r2= 0.86; CMJ with hands on the hips and the snatch r=0.93 r2= 0.86, clean and jerk r= 0.93 r2= 0.86, back squat r= 0.95 r2= 0.90 and deadlift r= 0.94 r2= 0.88; for the SJA and the snatch r=0.8 r2= 0.64, clean and jerk r=0.81 r2= 0.65, back squat r=0.82 r2= 0.67 and deadlift r=0.78 r2= 0.60; for the SJ with hands on the hips and the snatch r= 0.76 r2= 0.57, clean and jerk r= 0.75 r2= 0.56, back squat r= 0.77 r2= 0.59 and deadlift r= 0.71 r2= 0.50. Significant correlation coefficients were not found for 1 RM in the snatch, clean and jerk, back squat and deadlift and the CMJ or SJ with and without arm swing in any of the following parameters: jump height (m), relative force (% of body weight), relative power output (W/kg of body weight).CONCLUSION The main finding is that the jump height (m) of the CMJ or SJ with or without arm swing did not correlate significantly with 1 RM in the snatch, clean and jerk, back squat and deadlift. Therefore, jump height measurement can be used as a motivation tool but not to predict maximum strength in Olympic bar exercises, or vice versa. We recommend using the average power output (W) parameter in the CMJ with using arms as a predictor of current performance level in exercises with an Olympic bar for men and women.Key words: snatch, clean and jerk, squat, deadlift, countermovement jump, squat jump

Comparing Active, Passive, and Combined Warm-Ups Among Junior Alpine Skiers in −7°C

Context: Warming up in very cold climates and maintaining an elevated body temperature prior to a race is challenging for snow-sport athletes. Purpose: To investigate the effects of active (ACT), passive (PAS), and a combination of ACT and PAS (COM) warm-ups on maximal physical performance in a subzero environment among snow-sport athletes. Methods: Ten junior alpine skiers completed 3 experimental trials in −7.2 (0.2)°C. The ACT involved 5 minutes of moderate cycling, 3 × 15-second accelerations, a 6-second sprint, 5 countermovement jumps (CMJs), and a 10-minute passive transition phase, while in PAS, participants wore a lower-body heated garment for 24 minutes. In COM, participants completed the active warm-up, then wore the heated garment during the transition phase. Two maximal CMJs and a 90-second maximal isokinetic cycling test followed the warm-up. Results: CMJ performance was likely (P = .150) and very likely (P = .013) greater in ACT and COM, respectively, versus PAS. Average power output during the cycling test was likely (P = .074) greater in ACT and COM versus PAS. Participants felt likely to almost certainly warmer (P < .01) and more comfortable (P = .161) during ACT and COM versus PAS. In addition, participants felt likely warmer (P = .136) and very likely more comfortable (P = .161) in COM versus ACT. Conclusions: COM resulted in significantly improved CMJ performance versus PAS while both ACT and COM led to likely improved 90-second cycling performance. Participants felt significantly warmer during ACT and COM versus PAS and likely warmer in COM versus ACT. Therefore, a combined warm-up is recommended for alpine skiers performing in subzero temperatures.

Stochastic Dynamics of a Piezoelectric Energy Harvester Subjected to Lévy Flight Excitations

Vibration energy harvesting seeks to exploit the energy of ambient random vibration for power generation, particularly in small scale devices. Piezoelectric transduction is often used as a conversion mechanism in harvesting and the random excitation is typically modeled as a Brownian stochastic process. However, non-Brownian excitations are of potential interest, particularly in the nonequilibrium regime of harvester dynamics. In this work, we investigate the averaged power output of a generic piezoelectric harvester driven by Brownian as well as (non-Brownian) Lévy stable excitations both in the linear and the Duffing regimes. First, a coupled system of stochastic differential equations that model the electromechanical system are presented. Numerical simulation results (based on the Euler-Maruyama scheme) that show the average power output from the system under Brownian and Lévy excitations are presented for the cases where the mechanical degree of freedom behaves as a linear as well as a Duffing oscillator. The results demonstrate that Lévy excitations result in higher expectation values of harvested power. In particular, increasing the noise intensity leads to significant increase in power output in the Levy case when compared with Brownian excitations.