We investigated the effect of carbohydrate mouth rinsing on resistance exercise performance. Fifteen recreationally trained women (age 26 AE 4 y; height 1.61.9 AE 5.1 m; weight 59.5 AE 8.2 kg) completed two resistance exercise bouts consisting of three sets of five exercises (half-squat, leg press, bench press, military press, and seated row) to volitional fatigue with a 10 repetition-maximum load. Immediately prior to and during the middle of each exercise bout, subjects mouth rinsed for 10 s with 100 mL of either a 6% maltodextrin solution (CHO) or an artificially flavored solution (PLA) in a randomized, double-blind, counterbalanced fashion. Heart rate and perceived exertion were compared between conditions using a 2 (conditions) Â 15 (time points) repeated measures ANOVA. Significant main effects were further analyzed using pairwise comparisons with Bonferroni post hoc tests. Total volume (exercises * sets * repetitions * load) between sessions was compared with a Student's t-test. Statistical significance was set at p 0.05 level of confidence. The CHO resulted in more repetitions performed during half-squat, bench press, military press, and seated row, for a significantly greater ($12%) total volume load lifted versus PLA (p ¼ 0.039, ES: 0.49). Rating of perceived exertion was also significantly lower in the CHO versus PLA (p ¼ 0.020, ES: 0.28). These data indicate that CHO mouth rinsing can enhance high-volume resistance exercise performance and lower ratings of perceived exertion.

The aim of this study was to evaluate the acute effects of high-intensity eccentric exercise (HI-ECC) combined with blood flow restriction (BFR) on muscle damage markers, and perceptual and cardiovascular responses. Nine healthy men (26 ± 1 years, BMI 24 ± 1 kg m ²) underwent unilateral elbow extension in two conditions: without (HI-ECC) and with BFR (HI-ECC+BFR). The HI-ECC protocol corresponded to three sets of 10 repetitions with 130% of maximal strength (1RM). The ratings of perceived exertion (RPE) and pain (RPP) were measured after each set. Muscle damage was evaluated by range of motion (ROM), upper arm circumference (CIR) and muscle soreness using a visual analogue scale at different moments (pre-exercise, immediately after, 24 and 48 h postexercise). Systolic (SBP), diastolic (DBP), mean blood pressure (MBP) and heart rate (HR) were measured before exercise and after each set. RPP was higher in HI-ECC+BFR than in HI-ECC after each set. Range of motion decreased postexercise in both conditions; however, in HI-ECC+BFR group, it returned to pre-exercise condition earlier (post-24 h) than HI-ECC (post-48 h). CIR increased only in HI-ECC, while no difference was observed in HI-ECC+BFR condition. Regarding cardiovascular responses, MBP and SBP did not change at any moment. HR showed similar increases in both conditions during exercise while DBP decreased only in HI-ECC condition. Thus, BFR attenuated HI-ECC-induced muscle damage and there was no increase in cardiovascular responses.

cfDNA increases in response to RE intensity even when not performed until exhaustion. cfDNA measured immediately after RE is a promising biomarker for muscle-performance decrement up to 48 h after a RE bout.

Load reduction did not yield a difference in hypertrophy or 10RM as compared with CON. However, RED 10 induced a significantly lower RPE. Thus, load reduction may be a beneficial strategy to reduce the perception of effort during training while achieving similar improvements in hypertrophy and strength.

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Purpose:The purpose of this study was to evaluate the effects of caffeine ingestion before a resistance exercise session on markers of muscle damage (CK, LDH, ALT, AST) and leukocyte levels.Methods:Fifteen soccer athletes completed two resistance exercise sessions that differed only in the ingestion of caffeine or a placebo preworkout.Results:CK concentration increased significantly following the caffeine session (415.8 ± 62.8 to 542.0 ± 73.5) and the placebo session (411.5 ± 43.3 to 545.8 ± 59.9), with no significant differences between sessions. Similarly, LDH concentration increased significantly following the caffeine session (377.5 ± 18.0 to 580.5 ± 36.1) and the placebo session (384.8 ± 13.9 to 570.4 ± 36.1), with no significant differences between sessions. Both sessions resulted in significant increases in the total leukocyte count (caffeine = 6.24 ± 2.08 to 8.84 ± 3.41; placebo = 6.36 ± 2.34 to 8.77 ± 3.20), neutrophils (caffeine = 3.37 ± 0.13 to 5.15 ± 0.28; placebo = 3.46 ± 0.17 to 5.12 ± 0.24), lymphocytes (caffeine = 2.19 ± 0.091 to 2.78 ± 0.10; placebo = 2.17 ± 0.100 to 2.75 ± 0.11), and monocytes (caffeine = 0.53 ± 0.02 to 0.72 ± 0.06; placebo = 0.56 ± 0.03 to 0.69 ± 0.04), with no significant differences between sessions.Conclusion:Ingestion of caffeine at 4.5 mg⋅kg-1 did not augment markers of muscle damage or leukocyte levels above that which occurs through resistance exercise alone.

BackgroundOxyElite Pro (OEP) is a dietary supplement to increase metabolism which contains as key stimulant the ingredient 1,3-dimethylamylamine (DMAA). Serious adverse effects have been reported after OEP consumption however, these effects are related to poisoning or overdose. To our knowledge, no one studied the effects of OEP at controlled doses. Thus, the aim of this study was to evaluate acute and chronic OEP affects, at controlled doses in Wistar rats, on physical performance, metabolic parameters, liver injury markers and oxidative stress markers and mitochondrial biogenesis in skeletal muscle.MethodsRats were divided in control, 4.3 mg OEP/kg, 12.9 mg OEP/kg and 25.8 mg OEP/kg. All groups were submitted to supplementation with OEP for 4 weeks and the experimental protocols were performed 30 min after the first OEP administration (acute response) and 30 min after the last OEP administration at the end of the forth week (chronic response).ResultsRunning distance and running time increased after acute administration of 12.9 mg OEP/kg (2.6-fold) and 25.8 mg OEP/kg (2.8-fold). Since no effect on the exercise tolerance test was observed at the lower OEP dose (4.3 mg OEP/kg), this group was removed from further analyzes. On other hand, running distance and running time decreased after daily supplementation for 4 weeks also in both groups (64% in 12.9 mg OEP/kg and 72% in 25.8 mg OEP/kg). Chronic supplementation at both 12.9 and 25.8 mg OEP/kg decreased TBARS levels in soleus muscle (36 and 31%) and liver (43 and 25%). AOPP was also decreased by both doses in the liver (39 and 45%). Chronic administration of the highest dose, 25.8 mg OEP/kg, was able to reduce mRNA expression of PGC-1α in soleus muscle (25%). No effect was found in other analyses such as spontaneous physical activity, body weight, food and water intake, hepatic toxicity, cardiac oxidative stress and mitochondrial DNA amount.ConclusionMaximum and not recommended doses of OEP ingested acutely presented stimulating effect on the ability to exercise. However, its daily consumption for 4 weeks showed antioxidant effects in soleus muscle and liver which may have decreased the PGC-1α mRNA expression on soleus muscle and contributed to the impaired performance in the exercise tolerance test.

RESUMOO treinamento de força (TF) intenso ocasiona danos na estrutura muscular, que podem ser detectados por meio de marcadores indiretos. OBJETIVO. Verificar se há alterações na atividade da creatina quinase (CK), da aspartato transaminase (AST) e alanina transaminase (ALT) com o TF em diferentes intervalos entre séries e exercícios. MÉTODOS. Treze voluntários (± 21,8 anos; ± 173,6 cm; ± 68,3 kg) realizaram o teste de uma repetição máxima (1RM) nos exercícios: supino reto, puxada (pulley), desenvolvimento sentado, tríceps (pulley) e rosca bíceps. Após sete dias, todos foram submetidos a uma coleta de sangue (PRE) e realizaram 4 séries máximas até a falha concêntrica com intensidade de 85% de 1RM e intervalos de 1 ou 3 minutos entre as séries e exercícios. Todos retornaram ao mesmo local 24, 48 e 72 horas após a sessão para mais uma coleta de sangue. Repetindo os procedimentos após uma semana, porém os voluntários que realizaram o teste com intervalo de 1 minuto na semana seguinte manteriam intervalos de 3 minutos e vice-versa. Realizou-se ANOVA mantendo como significância p<0,05. RESULTADOS. Houve redução significativa do número de repetições a cada série de todos os exercícios com 1 e 3 minutos de intervalo. Observou-se um aumento significativo da atividade sérica de CK e de AST 24, 48 e 72 horas utilizando ambos os intervalos. ALT não se alterou. CONCLUSÃO. O TF causou aumento na atividade de CK e AST, mas sem apresentar diferenças com os intervalos utilizados. Porém, pequenos intervalos reduzem o volume total de repetições.Palavras-chave: treinamento resistido, músculo esquelético; força; creatina-quinase; fadiga. ABSTRACTThe heavy resistance strength training causes damage to the muscle structure that can be detected through indirect markers. OBJECTIVE. Examine whether there are changes in creatine kinase (CK), aspartate transaminase (AST) and alanine transaminase (ALT) activity with the resistance strength training in different intervals between sets and exercises. METHODS. Thirteen volunteers (± 21,8 years; ± 173,6 cm; ± 68,3 Kg) performed the one repetition maximum test (1RM) in the exercises: bench press, driven (pulley), sitting development, tríceps (pulley) and biceps. After seven days all were submitted a blood sample (PRE) and they performed 4 maximum sets by concentric failure with intensity the 85% of 1RM and intervals 1 and 3 minutes between sets and exercises. All returned to the same place