Effect of a 4-week fish oil supplementation on neuromuscular performance after exhaustive exercise in young healthy men

Neuromuscular function is one of the important factors affecting athletic performance. Previous studies have shown that fish oil supplementation can improve performance. This study investigated the effect of fish oil on neuromuscular performance after exhausting exercise. Eighteen healthy men (mean ± standard deviation; age 26.9±2.6 years; weight 78.33±10.42 kg; height 175.8±4.9 cm; body fat percentage 18.40±5.46%) voluntarily participated and were randomly assigned to fish and corn oil groups in a double blind manner. Participants received 6 g/day of oil for 4 weeks, while maintaining baseline diet and training status during the study. Changes in maximal voluntary contraction (MVC) of the tibialis anterior muscle, neuromuscular propagation of tibialis anterior muscle (M-wave), corticospinal excitability (MEP: motor evoked potential), and the rate of perceived exertion (RPE) were evaluated before and after supplementation in response to a modified Bruce exhausting protocol. Group differences in changes in each variable following supplementation were assessed by two-way analysis of variances (ANOVA). Compared to corn oil, fish oil demonstrated less perceived exertion at the end of exhaustive exercise (F=9.72, P=0.001) after supplementation, and normalised MEP to M-wave showed a trend (F=3.83, P=0.071). However, M-wave peak to peak amplitudes changes were not significant between the groups (P>0.05). In addition, significant differences were observed between baseline MVC values of the group following supplementation. Thus, it seems that fish oil can improve corticospinal excitability, thereby improving neuromuscular function in exhausting activities. Therefore, fish oil supplementation may be recommended to increase performance in activities otherwise limited. However, the mechanism underlying this effect remains to be elucidated.

The effects of acute consumption of carbohydrate-protein supplement in varied ratios on CrossFit athletes' performance in two CrossFit exercises: a randomized cross-over trial

BACKGROUND

CrossFit is becoming popular over the past few years, and various supplementation ways have been utilized by exercise physiologists to enhance CrossFit athletes' performance. This study aimed to evaluate the effects of consuming preworkout carbohydrate-protein supplements on CrossFit athletes' performance.

METHODS

Well-trained CrossFit athletes (8 men; 25.62±3.02 years) were randomized to a single-blind, placebo controlled, crossover design (7-day washout) to performed six bouts of two CrossFit workouts: Fight Gone Bad (FGB) and Cindy (CI). One hour and immediately before the onset of each bout, the subjects consumed carbohydrate-protein supplement in two ratios (2:2 or 3:1) or placebo (P): FGB+2:2, FGB+3:1, FGB+P, CI+2:2, CI+3:1, and CI+P. To value the differentiation in performances, the performed each subject repetitions in FGB and CI were recorded in the bouts.

RESULTS

Repeated measure analysis of variance was used to analyze the data, and the level of significance set for the study was P≤0.05. No significant difference was observed in the total number of repetitions performed in FGB (P=0.275) or CI (P=0.789) workouts in supplements and placebo groups.

CONCLUSIONS

These results indicate that acute consumption of preworkout carbohydrate-protein supplement may not enhance the CrossFit athletes' performance in FGB and CI workouts.

Wet-cupping induces anti-inflammatory action in response to vigorous exercise among martial arts athletes: A pilot study

PURPOSE

The aim of the present study was to investigate potential anti-inflammatory effects of wet-cupping prior to a moderate-to-vigorous exercise test among martial arts athletes.

METHODS

Twenty-one male karate athletes voluntarily participated in this study and were randomly divided into 3 groups: vigorous exercise (VE, n = 7), cupping (CT, n = 7) and cupping plus vigorous exercise (VECT, n = 7). Participants in exercise groups performed an exercise test while participants in CT received cupping therapy, and participants in VECT received cupping therapy plus exercise. Inflammatory markers (i.e., interlukin-6, IL-6, and tumor necrosis factor-α, TNF-α) were assessed prior to, immediately, 30 min, and 24 h after cupping therapy, vigorous exercise test, and their combination.

RESULTS

IL-6 values were significantly lower immediately after cupping intervention in CT as compared to baseline (P < 0.025). IL-6 significantly increased immediately and 30 min post-exercise in VE in comparison with baseline (P < 0.025). IL-6 was also significantly higher at 24 h post-exercise in CTVE as compared to baseline (P < 0.025). TNF-α values were significantly lower in CT as compared to VE and CTVE at immediately and 30 min post-exercise (P < 0.01). TNF-α significantly decreased immediately and 30 min after cupping intervention in CT as compared to baseline (P < 0.01). Conversely, TNF-α significantly increased immediately after exercise in VE as compared to baseline (P < 0.025). TNF-α also significantly increased at 30 min and 24 h post-exercise in CTVE in comparison with baseline (P < 0.025).

CONCLUSION

Our findings showed that exercise-induced augmentation in inflammatory markers were lower in athletes who received cupping therapy, suggesting such therapy may be an avenue to mitigate the inflammatory response to vigorous exercise among martial arts athletes. A large-scale clinical study is needed to confirm the findings of the present study.

The effect of 6 weeks of high intensity interval training on myelin biomarkers and demyelination in experimental autoimmune encephalomyelitis model

Exercise has been shown to increase myelin biomarkers such as klotho and PLP and improve clinical and pathological symptoms using the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). In the present study, we evaluated whether 6 weeks of high-intensity interval training (HIIT) prior to induction of EAE increase klotho and/or PLP and attenuate the severity of symptoms and/or disease progression in EAE model. Our data demonstrate that HIIT increased klotho and PLP and decreased disability. These proteins are associated with maintaining myelination and further research is required to examine potential clinical relevance.

High intensity exercise preconditioning provides differential protection against brain injury following experimental stroke

AIMS

Different modes of physical activity provide cerebrovascular protection against thromboembolic events. Based on recent reports high intensity exercise protocols appear to raise cerebral VEGF levels leading to efficient cerebral angiogenesis. The present study aims to address if moderate continuous training (MCT) and high intensity interval training (HIT) differ in preconditioning against ischemic stroke.

METHODS

Wistar rats were subjected to HIT or MCT for 8 weeks before transient middle cerebral artery occlusion (tMCAO) surgery. As indexes for improved angiogenic signals, VEGF-A and its pivotal receptor VEGF-R2 were immunoblotted just before occlusive stroke.

KEY FINDINGS

Both training protocols induced a remarkable protection against neurological deficit and tissue injury following stroke. Cerebral infarctions were better improved in HIT animals which explained the slightly but not significantly higher neurological function. HIT brains developed higher levels of cortical VEGF-A and striatal VEGF-R2.

SIGNIFICANCE

These data conclude preconditioning with high intensity protocols might excel continued moderate exercise to induce VEGF signaling and alleviate stroke outcomes. Further investigations may provide complementary mechanistic views.

Exercise training with concomitant nitric oxide synthase inhibition improved anxiogenic behavior, spatial cognition, and BDNF/P70S6 kinase activation in 20-month-old rats

This study aimed to investigate the effect of exercise and nitric oxide synthase (NOS) inhibition on memory, anxiety, and protein levels of brain-derived neurotrophic factor (BDNF) and P70S6 kinase (P70S6K). Twenty-month-old rats were divided into 6 groups: a control group, 2 groups treated with l-nitro-arginine methyl ester (L-NAME) (25 or 100 mg/kg) for 63 days, 2 groups treated with L-NAME (25 or 100 mg/kg) for 63 days plus 2 months of exercise, and 1 group treated with exercise. Behavioral tests were conducted to determine the anxiolytic and memory-improving role of exercise and NOS inhibition. BDNF, P70S6K, and cleaved caspase-3 protein levels in the hippocampus and prefrontal cortex were evaluated by Western blotting. Exercise and L-NAME (25 mg/kg) or their combination had an anxiolytic effect and improved spatial memory in old rats compared with the control or exercised group, respectively. Exercise and treatment with a low dose of L-NAME (25 mg/kg) each increased BDNF and P70S6K in the hippocampus and prefrontal cortex compared with levels in control rats. In comparison with exercise alone, co-treatment with exercise and a low dose of L-NAME (25 mg/kg) also increased BDNF and P70S6K in the hippocampus. The neuronal level of cleaved caspase-3 was reduced in the L-NAME (25 mg/kg) + exercise group compared with the exercised group. The L-NAME (100 mg/kg) + exercise treatment had no positive behavioral or molecular effects compared with exercise alone. The protective role of NOS inhibition and aerobic exercise against aging is probably modulated via BDNF and P70S6K in the brain.

Effects of exercise at individual anaerobic threshold and maximal fat oxidation intensities on plasma levels of nesfatin-1 and metabolic health biomarkers

Exercise is recognized as an effective method of weight management and short-term appetite regulation tool. The effect of different exercise intensities on appetite regulation hormones in healthy overweight participants has not been intensively studied. The aim of this study was to examine the influence of exercise at individual anaerobic threshold (IAT) and maximal fat oxidation (Fatmax) intensities on the nesfatin-1 response and metabolic health biomarkers in overweight men. Nine healthy overweight males (age, 23.1 ± 1.1 years) volunteered in this study in a counterbalanced order. Blood samples were obtained before, immediately after, and following the first 45 min of recovery for measuring plasma variables. There was significant decrease in plasma levels of nesfatin-1 and leptin after exercise at the IAT intensity which remained lower than baseline following 45 min of recovery. However, nesfatin-1 and leptin levels did not change significantly in any time courses of Fatmax intensity (P > 0.09). Plasma interleukin-6 (IL-6) concentration increased during exercise in both intensities (P < 0.05), whereas changes in free fatty acids (FFAs) and epinephrine concentrations were significant only at the IAT. In addition, a significant correlation was found among nesfatin-1 levels with insulin (r = 0.39, P < 0.05) and glucose (r = 0.41, P < 0.05) at basal and in response to exercise. These results indicate that IAT has a greater exercise-induced appetite regulation effect compared with Fat(max). Based on these data, the intensity of exercise may have an important role in changes of nesfatin-1, leptin, FFA, and epinephrine concentrations even though this was not the case for IL-6 and insulin resistance.

The correlation between resting serum leptin and serum angiogenic indices at rest and after submaximal exercise

BACKGROUND

The effect of leptin as stimulant angiogenic factor has been studied. But the association of leptin levels and exercise-induced angiogenesis has not been studied. Accordingly, the researchers investigated whether there were any differences in circulating serum VEGF, MMP-2 and MMP-9 among high and low resting leptin individuals at rest or in response to submaximal exercise.

MATERIALS AND METHODS

For this purpose the researchers defined two groups with high and low resting leptin levels. Fifteen subjects with high resting leptin (23.57±9.14ng/ml and Vo(2) max=29.46±3.62ml/kg.min) and fifteen subjects with low resting leptin level (1.04±0.49ng/ml and Vo(2) max=37.99±4.63ml/kgmin) exercised for 1h (1h) at 70% of Vo(2) max. Antecubital vein blood was collected at rest, immediately and 2h post exercise. Serum VEGF, MMP-2 and MMP-9 was measured by ELISA method.

RESULTS

Results of the study showed that the resting serum levels of VEGF, MMP-2 and MMP-9 didn't have any correlation with basic levels of leptin. In low leptin group the levels of VEGF and MMP-2 in immediately post exercise decreased significantly, but in high leptin group, only VEGF decreased significantly. 2h post exercise; the VEGF level in the low resting leptin group was significantly lower than that of its basal level. Beside, MMP-2 in the high and low basic levels of leptin groups were significantly increased compared to that of immediately post exercise. But the amount of MMP-9 did not change significantly in response to exercise in two groups. There were not any differences in the changes of VEGF, MMP-2 and MMP-9 in response to exercise between two groups. Furthermore, resting leptin had a significant correlation with V0(2) max.

CONCLUSION

The obtained results showed that the serum VEGF, MMP-2 and MMP-9 did not have any correlation with basic levels of leptin. In addition, it was concluded that levels of different resting leptin is ineffective on serum levels of VEGF, MMP-2 and MMP-9 at rest and in response to exercise in normal healthy subjects.