Oxidative Stress Parameters and Its Associations With Arterial Stiffness in Competitive Powerlifting Athletes After 12-Week Supervised Strength Training.

Jürgenson, J, Serg, M, Kampus, P, Kals, J, Zagura, M, Viru, M, Zilmer, K, Zilmer, M, Eha, J, and Unt, E. Oxidative stress parameters and its associations with arterial stiffness in competitive powerlifting athletes after 12-week supervised strength training. J Strength Cond Res 33(7): 1816-1822, 2019-Available studies have not revealed a clear understanding of the impact of intensive strength training on arterial stiffness and oxidative stress (OxS) parameters, which may have a significant impact on further cardiovascular health of an athlete. The purpose of this study was to evaluate the effect of a 12-week supervised strength training program (SSTP) on oxidative stress indices and its relationship with arterial stiffness in powerlifting athletes. A total of 19 men (28 ± 6 years) exercised for 12 weeks (4 days per week with intensity 60-90% assessed from 1 repetition maximum, 90-120 minutes per session). Oxidative stress parameters and arterial stiffness (SphygmoCor 7.1) were measured before and after SSTP. The study results showed that total peroxide concentration increased and total antioxidant capacity decreased significantly after SSTP. There were no significant changes in carotid-femoral pulse wave velocity (cfPWV) or in the augmentation index. Correlation analysis revealed that the magnitude of the increase of cfPWV was significantly related to the increase of OxS. The current study demonstrated that a 12-week SSTP in powerlifting athletes produced significant changes in OxS indices, which were positively related to increased aortic stiffness. This novel finding may have significant implications about the effect of OxS on cardiovascular health after high-intensity strength training. Furthermore, strength and conditioningcoaches may have to consider the long-term exercise-induced changes in OxS on an individual level, where increased OxS leads to impaired arterial stiffness and cardiovascular health.

Impact of Low Volume Velocity-Controlled vs. Repetition to Failure Resistance Training Session on Measures of Explosive Performance in a Team of Adolescents Basketball Players.

This study examined the short-term effects (post 6 h and 24 h) of two equated (70% of 1 repetition maximum (1-RM)) low volume resistance exercise protocols: (i) velocity-controlled (VC) and (ii) repetition to failure (RTF) on upper and lower body performance in competitive adolescent male basketball players. Following a randomized, counterbalanced design, ten participants (age: 16 ± 0.5 years) completed either VC or RTF separated by 72 h. VC consisted of 4 sets of 5 explosive repetitions (≥90% of the maximum velocity). RTF involved 2 sets of 10-RM (with no velocity control). Measurements of 20-m sprint, countermovement jump (CMJ) and medicine ball toss (MBT) were collected before (baseline), post 6 h and 24 h after either VC or RTF. Increases of CMJ post 6 h (VC, +6.7%; RTF, +2.4%) and MBT post 24 h (VC, +4.6%; RTF, +4.2%) were observed after both VC and RTF. Only VC potentiated CMJ after 24 h (+2.0 ± 2.3%). No other changes or differences between protocols were observed. Performing a low volume exercise protocol, either VC or RTF, induced similar potentiation effects on the vertical jump (post 6 h) and medicine ball toss (post 24 h) in adolescent basketball players. Only the VC protocol was still effective to potentiate CMJ performance after 24 h.

Better Economy on Indoor Track Compared to Treadmill Running With 1% Inclination.

Purpose: The purpose of this study was to investigate the differences in metabolic responses between the track and the treadmill (1% inclination) running. The latter is recommended for use in laboratory settings to mimic outdoor running. Method: Seventeen male endurance athletes (mean 25.8, s = 3.8 years) performed 4-min running bouts on an indoor track and the treadmill. Results: At all speeds (11, 13, and 15 km·h-1) athletes showed better economy on the track running compared to the treadmill expressed as oxygen (7.9%, 5.2%, and 2.8%) and caloric (7.0%, 5.3%, and 2.6%) unit cost. Rating of perceived exertion was evaluated substantially higher at all speeds on the treadmill (F(1,16) = 31.45, p < .001, η2p = .663) compared to running on the track. Participants presented lower heart rate (F(1,16) = 13.74, p = .002, η2p = .462) on the track at the speed of 11 and 13 km·h-1 compared to the treadmill, but not at 15 km·h-1 (p = .021). Conclusions: We conclude that constant inclination (i.e.. 1%) during the treadmill test might not be suitable to reproduce comparable effort to running on the track; rather, there is an optimal treadmill inclination for different intensities to reproduce similar effort compared to the track running.

Comparison of the hormonal responses to exhaustive incremental exercise in adolescent and young adult males.

OBJECTIVE: Evaluate hormonal responses to incremental-stage exercise (EX) test to exhaustion in adolescents. SUBJECTS AND METHODS: Adolescents were tested at 16 years of age in Tanner Stage 4 (TS4) and at 17 years of age in Tanner Stage 5 (TS5) (n = 6). Adults were tested at 21 ± 1 y. (X ± SD) (n = 4) and served as controls. Blood samples were taken at rest, at the end of each EX stage. RESULTS: Main effects for EX in cortisol (p < 0.01, increasing with each EX stage) and for subject group for testosterone (T) occurred (p < 0.01; TS4 < TS5, adults). Interaction effect of group by EX stage occurred for GH (p < 0.05). GH increased in response to EX in all groups, however, the magnitude of increase was significantly less for TS5 and adults than TS4. CONCLUSIONS: Differences in T and GH responses for TS4 than those for TS5 and adults reflect the differing maturation levels of the endocrine system between Tanner Stages. TS5 adolescents are more similar to young adults in hormonal responses to EX than are TS4 adolescents.

Comparison of the hormonal responses to exhaustive incremental exercise in adolescent and young adult males / Comparação das respostas hormonais ao exercício incremental até exaustão em adolescentes e adultos jovens do sexo masculino

OBJECTIVE: Evaluate hormonal responses to incremental-stage exercise (EX) test to exhaustion in adolescents. SUBJECTS AND METHODS: Adolescents were tested at 16 years of age in Tanner Stage 4 (TS4) and at 17 years of age in Tanner Stage 5 (TS5) (n = 6). Adults were tested at 21 ± 1 y. (X ± SD) (n = 4) and served as controls. Blood samples were taken at rest, at the end of each EX stage. RESULTS: Main effects for EX in cortisol (p < 0.01, increasing with each EX stage) and for subject group for testosterone (T) occurred (p < 0.01; TS4 < TS5, adults). Interaction effect of group by EX stage occurred for GH (p < 0.05). GH increased in response to EX in all groups, however, the magnitude of increase was significantly less for TS5 and adults than TS4. CONCLUSIONS: Differences in T and GH responses for TS4 than those for TS5 and adults reflect the differing maturation levels of the endocrine system between Tanner Stages. TS5 adolescents are more similar to young adults in hormonal responses to EX than are TS4 adolescents.

OBJETIVO: Avaliar as respostas hormonais ao teste de exercício em estágios incrementais (EX) até exaustão. SUJEITOS E MÉTODOS: Foram examinados adolescentes com 16 anos de idade e índice Tanner 4 (TS4) e com 17 anos de idade e índice Tanner Stage 5 (TS5) (n = 6), e adultos com 21 ± 1 anos de idade. (X ± SD) (n = 4), estes últimos compondo o grupo controle. As amostras de sangue foram retiradas no repouso e ao final de cada estágio EX. RESULTADOS: Os principais efeitos observados no EX ocorreram no cortisol (p < 0,01, aumentou com a elevação do estágio EX) e no grupo de testosterona (p < 0,01; TS4 < TS5, adultos). Houve efeito de interação entre grupos e por estágio de EX no grupo de hormônio de crescimento (p < 0,05). O hormônio de crescimento aumentou em todos os grupos em resposta ao EX, no entanto, a magnitude dos aumentos observados foi significativamente menor em TS5 e nos adultos do que em TS4. CONCLUSÕES: As diferenças verificadas nas respostas dos grupos de testosterona e hormônio de crescimento em TS4 em relação ao TS5 e adultos refletem os diferentes níveis de maturação do sistema endócrino entre os estágios do índice de Tanner. Os adolescentes no TS5 se assimilam mais aos jovens adultos do que aos adolescentes TS4, quanto a suas respostas hormonais ao EX.