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Kamandulis, S, Bruzas, V, Mockus, P, Stasiulis, A, Snieckus, A, and Venckunas, T. Sport-specific repeated sprint training improves punching ability and upper-body aerobic power in experienced amateur boxers. J Strength Cond Res 32(5): 1214-1221, 2018-High-intensity interval training improves endurance and performance, but it is unclear whether sprint-type upper-body interval training is similarly effective. This study explored the effects of 4-week sport-specific sprint interval training on punch characteristics and endurance capacity in boxers. Experienced male amateur boxers (n = 18) participated in this 4-week training study and were divided into an experimental group (EG) and a control group (CG) (n = 9 per group). Both groups completed standard low-intensity training. The EG also completed 3 rounds (14 sets of 3-second all-out punching with a 10-second rest) of a simulated fight using a punching bag with a 1-minute rest between rounds 3 times per week, whereas the CG performed the same 3 rounds of a simulated fight at low intensity. Three rounds of 14 sets of 3-second all-out punching of a bag ergometer with a 10-second rest were performed to measure punching abilities. Peak oxygen consumption and peak power were measured during progressive arm cranking before and after training. In response to training peak oxygen consumption and peak power in arm-cranking test increased in EG, also punching force increased and maintenance of punching frequency and punch force improved during the simulated fight, which resulted in greater cumulative force throughout the 3 rounds. There were no changes in the CG. The study shows that 1 month of all-out punching training (3 sessions per week with ∼2 minutes of all-out punching per session) improved both upper-body aerobic power and punching abilities in experienced amateur boxers.

We hypothesized that endurance athletes have lower muscle power than power athletes due to a 25 combination of weaker and slower muscles, while their higher endurance is attributable to better oxygen 26 extraction, reflecting a higher muscle oxidative capacity and larger stroke volume. 27 Endurance (n=87; distance runners, road cyclists, paddlers, skiers), power (n=77; sprinters, throwers, 28 combat sport athletes, body builders), team (n=64; basketball, soccer, volleyball) and non-athletes 29 (n=223) performed a countermovement jump and an incremental running test to estimate their maximal 30 anaerobic and aerobic power (VO2max), respectively. Dynamometry and M-mode echocardiography 31 were used to measure muscle strength and stroke volume. The VO2max (L•min-1) was larger in 32 endurance and team athletes than in power athletes and non-athletes (p<0.05). Athletes had a larger 33 stroke volume, left ventricular mass and left ventricular wall thickness than non-athletes (p<0.02), but 34 there were no significant differences between athlete groups. The higher anaerobic power in power and 35 team athletes than in endurance athletes and non-athletes (p<0.001) was associated with a larger force 36 (p<0.001), but not faster contractile properties. Endurance athletes (20.6%) had a higher (p<0.05) 37 aerobic:anaerobic power ratio than controls and power and team athletes (14.0-15.3%). The larger 38 oxygen pulse, without significant differences in stroke volume, in endurance than power athletes 39 indicates a larger oxygen extraction during exercise. Power athletes had stronger, but not faster, muscles 40 than endurance athletes. The similar VO2max in endurance and team athletes and similar jump power 41 in team and power athletes, suggests that concurrent training does not necessarily impair power or 42 endurance performance. 43

BackgroundThe effect of deep mineral water (DMW) with moderate mineralization on the recovery of physical performance after prolonged dehydrating aerobic exercise in the heat was studied in nine healthy, physically active (VO2max = 45.8 ± 8.4 mL kg−1 min−1) women aged 24.0 ± 3.7 years.MethodsWe conducted a randomized, double-blind, placebo-controlled crossover human study to evaluate the effect of ingestion of natural mineral water extracted from a depth of 689 m on recovery from prolonged fatiguing aerobic running conducted at 30°C.ResultsMean body weight decreased by 2.6–2.8% following dehydrating exercise. VO2max was 9% higher after 4 h of recovery after rehydrating with DMW compared with plain water. Leg muscle power recovered better during the slow phase of recovery and was significantly higher after 48 h of recovery after rehydrating with DMW compared with plain water.ConclusionsDMW with moderate mineralization was more effective in inducing recovery of aerobic capacity and leg muscle power compared with plain water following prolonged dehydrating aerobic running exercise.

Objectives: To determine the effect of leg immersion in cold water after stretch-shortening exercise (SSE) on the time-course of indirect indicators of exercise-induced muscle damage (EIMD). Methods: Twenty healthy untrained men twice performed SSE consisting of 100 drop jumps (DJs) from 0.75 m height performed with maximal intensity with an interval of 20 s between the jumps. DJs were performed with counter-movement to 90 degrees angle in the knee and with immediate maximal rebounds. After SSE the subject's legs immediately, as well as after 4 h, 8 h and 24 h, were immersed into a bath filled with water at 15 ± 1 • C. Quadriceps muscle voluntary contraction force (MVCF) and force evoked by electrostimulation (ESF) at different frequencies and at different muscle length, jump height (H), muscle soreness and creatine kinase (CK) activity in the blood were measured before SSE, immediately after SSE and within 72 h of recovery. Results: After stretch-shortening exercise MVCF, ESF and H were significantly (P < 0.001) decreased and were not restored even after 72 h in the group that did not receive the cooling. Within 24-48 h after SSE the subjects felt great muscle pain and CK activity in their blood was increased (P < 0.001). The cooling significantly accelerated the disappearance of all these indicators, except for low-frequency fatigue, but only within 24-72 h after SSE. Conclusion: Cold water immersion after SSE accelerates the disappearance of the majority of indirect indicators of EIMD.