Journal of strength and conditioning research
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J Strength Cond Res · Oct 2015
Influence of Load Intensity on Postexercise Hypotension and Heart Rate Variability after a Strength Training Session.
The purpose of this study was to compare blood pressure and heart rate variability (HRV) responses in trained men after strength training (ST) sessions with loads of 60, 70, and 80% of a 1 repetition maximum (1RM). Eleven men (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172.0 ± 4.0 cm; body mass index: 25.0 ± 1.96 kg·m(-2); %G: 18.3 ± 6.4) with at least 6-month ST experience participated in this study. After assessment of 1RM loads for the bench press (BP), lat pull-down (LPD), shoulder press (SP), biceps curl (BC), triceps extension (TE), leg press (LP), leg extension (LE), and leg curl (LC), subjects performed 3 experimental sessions in random order. ⋯ The results demonstrated a greater duration of postexercise hypotension (PEH) after the 70% of 1RM session vs. the 60 or 80% of 1RM session. These results indicate that the load/volume associated with completion of 8-10 repetitions at 70% of 1RM load may provide the best stimulus for the PEH response when compared with training with a 60 or 80% of 1RM loads. In conclusion, strength and conditioning professionals may prescribe exercises with 60, 70, and 80% of 1RM loads if the intent is to elicit an acute decrease in blood pressure after an ST session; however, 70% of 1RM provides a longer PEH.
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J Strength Cond Res · Aug 2015
Muscular Strength and Power Correlates of Tackling Ability in Semiprofessional Rugby League Players.
This study investigated the relationship between muscular strength and power and tackling ability in semiprofessional rugby league players. Thirty-six semiprofessional (mean ± SD age, 23.1 ± 3.6 years) rugby league players, from 3 distinct playing divisions (first grade, second grade, and under 20s), underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up [PPU]), and lower-body power (countermovement jump). Muscular strength relative to body mass was also calculated. ⋯ The strongest correlates of tackling ability in under 20s players were squat (r = 0.77), bench press (r = 0.70), and PPU (r = 0.65). The findings of this study demonstrate that muscular strength and upper-body power contribute to tackling ability in semiprofessional rugby league players. Therefore, as long as the technical aspects of tackling technique are adequately coached and practiced, then enhancements in muscular strength and power may serve as foundational components to underpin improvement in tackling ability.
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J Strength Cond Res · Jun 2015
Randomized Controlled Trial Comparative StudyInfluence of number of sets on blood pressure and heart rate variability after a strength training session.
The purpose of this study was to compare the acute effects of 1, 3, and 5 sets of strength training (ST), on heart rate variability (HRV) and blood pressure. Eleven male volunteers (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172 ± 4 cm) with at least 6 months previous experience in ST participated in the study. After determining the 1 repetition maximum (1RM) load for the bench press (BP), lat pull down (LPD), shoulder press (SP), biceps curl (BC), triceps extension (TE), leg press (LP), leg extension (LE), and leg curl (LC), the participants performed 3 different exercise sequences in a random order and 72 hours apart. ⋯ Therefore, ST composed of upper- and lower-body exercises and performed with high volumes are capable of producing significant and extended postexercise hypotensive response. In conclusion, strength and conditioning professionals can prescribe 5 sets per exercises if the goal is to reduce blood pressure after training. In addition, these findings may have importance, specifically in the early phase of high blood pressure development, but more research is needed in hypertensive populations to validate this hypothesis.
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J Strength Cond Res · Apr 2015
Functional movement screen differences between male and female secondary school athletes.
The functional movement screen (FMS) is commonly used to assess movement capacity and determine injury risk. Evidence suggests that athletes who score 14 points or less on the FMS are at increased risk for injury, but differences between males and females have been minimally studied. The purpose of this study was to investigate sex differences in FMS scores of secondary school athletes. ⋯ Healthy secondary school female athletes scored 14 or less on the FMS total composite score and significantly lower in general compared with healthy secondary school male athletes, which suggests these female athletes may be at higher risk for injury. Factors that may contribute to increased injury risk include deficits in mobility, core stabilization, and coordinated movement patterns. Clinicians should be aware of possible sex differences when using the FMS and developing injury prevention programs.
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J Strength Cond Res · Apr 2015
Overrepresentation of the ACTN3 XX genotype in elite canoe and kayak paddlers.
The aim of the study was to examine the association between the ACTN3 R577X polymorphism in canoe sprint athletes (canoe and kayak paddlers) and their results at 200- or 1000-m distance. Eighty-six European white male athletes divided into 2 groups-successful, who were outstanding at national championships, and nonsuccessful in these competitions-and 354 nonathletic controls were included in this study. The R577X polymorphism of ACTN3 was typed using PCR-RFLP. ⋯ The odds ratio (OR) for successful 1000-m athletes harboring the XX genotype compared with sedentary controls was 2.95 (95% confidence interval [CI]: 1.37-6.35), but the OR for nonsuccessful 200-m athletes having the XX genotype compared with controls was 2.64 (95% CI: 1.30-5.36). These results suggest that factors associated with the ACTN3 XX genotype in canoe and kayak paddlers might provide some competitive advantage in performance at 1000 m, but it seems to limit at 200 m. Further studies aimed at development of training strategies based on genetic factors are needed.