Effects of six weeks of resistance-endurance training on microRNA-29 expression in the heart of ovariectomised rats

INTRODUCTION

Heart disease risk rises with age. However, women's symptoms become more pronounced following the onset of menopause. The aim of the present study was to evaluate the effects of six weeks of combined resistance-endurance (RE) training on microRNA-29 expression in the heart of ovariectomised rats.

MATERIAL AND METHODS

Thirty female Wistar rats were divided into three groups: 1) sham (SHAM); 2) ovariectomy (OVX); and 3) OVX with RE training (OVX + RE). The effects of these treatments on cardiac microRNA-29 expression were measured using real-time PCR. Data were analysed using a 2 × 3 ANOVA and Tukey post-hoc comparisons and presented as mean ±SEM.

RESULTS

Ovariectomy resulted in a significant down-regulation in the heart microRNA-29 gene expression of OVX (0.265 ±0.031 fold changes), OVX + RE (0.699 ±0.038 fold changes) in animals vs. sham animals (1 ±0 fold changes; all, p < 0.05) following six weeks of treatment. However, microRNA-29 expression in the OVX + RE group was significantly greater than in the OVX group (p < 0.05).

CONCLUSIONS

Our findings suggest that the six weeks of regular RE training attenuate the reduction in heart muscle microRNA-29 expression observed in ovariectomised rates. If our findings carry over to humans, such an exercise regimen could be beneficial to the cardiovascular disease risk in women during menopause.

Daily timing of salivary cortisol responses and aerobic performance in lean and obese active females

The main aim of the present study was to study the effects of morning and afternoon physical activities on cortisol responses in obese and lean women. Twenty women volunteered to participate in this study. Subjects were divided into an obese group (BMI =29.1 kg/m2) and a lean group (BMI =19 kg/m2). All subjects participated in an exercise program consisting of treadmill running at 65+/-2 % VO2max until exhaustion. In order to study effects of circadian rhythm, exercise was performed at a similar intensity and in similar environmental conditions at both 8:00 AM and 4:00 PM. Saliva specimens were collected at rest 20 minutes before activity and then immediately after the exercise in both morning and afternoon sessions. Morning and afternoon exercise resulted in a significant increase in salivary cortisol concentrations compared to basal levels in both lean and obese women (p<0.05), though the change in cortisol concentrations were higher in lean. The aerobic function of lean and obese women in the morning and afternoon showed a significant increase of 13.8 % and 5.9 %; respectively, with lean being consistently higher than obese. In conclusion, the stress response to exercise is related to circadian rhythm and individual's body weight. Based on the results of this study, it is suggested that overweight women perform exercises in the afternoon to minimize the stress response for the exercise volume performed (Tab. 1, Fig. 3, Ref. 39). Full Text in free PDF www.bmj.sk.

The effects of a 4-week coffeeberry supplementation on antioxidant status, endurance, and anaerobic performance in college athletes

The main aim of this investigation was to evaluate the changes in total antioxidant capacity (TAC) and aerobic and anaerobic performance induced by supplementation of coffeeberry (CB) formulation for 4 weeks in college athletes. Twenty college athletes (14 males and 6 females) were allocated to two randomly assigned trials. Subjects in the CB group orally ingested capsules that contained CB formulation at a dose of 800 mg per day in two equal doses for 28 days, while subjects in the placebo (P) group ingested an equal number of identical-looking caps that contained cellulose. There were no changes in glucose, cholesterol, and lipoproteins within or between trials (p > 0.05). Total antioxidant capacity (TAC) was significantly higher in the CB versus P trial at the post- supplementation trial (1.66 +/- 0.16 vs. 1.51 +/- 0.05 mmol/L; p < 0.05). There were no statistically significant changes in average anaerobic power, index of anaerobic fatigue, maximal heart rate, blood lactate, and maximal oxygen uptake within or between trials (p > 0.05). Heart rate recovery (HRR) index increased significantly in CB group as compared with baseline level (38 +/- 4 vs. 32 +/- 5 beats/min; p < 0.05). Blood lactate after 10 min of recovery (Lact(rec)) significantly decreased in the CB group after supplementation protocol as compared with initial results (7.6 +/- 4.2 vs. 5.5 +/- 2.6 mmol/L; p < 0.05). No subject reported any side effects from CB or P. The results of the present study indicate that supplementation with a CB formulation slightly increased antioxidant capacity, but there were minimal effects on recovery parameters after exercise in college athletes.