Effect of six weeks of endurance exercise and following detraining on serum brain derived neurotrophic factor and memory performance in middle aged males with metabolic syndrome.

AIM: Brain derived neurotrophic factor (BDNF) and physical inactivity contribute to the development of metabolic syndrome (MetS). Aerobic training has been reported to improve MetS, however less attention has been directed toward the role of training and detraining on cognitive function in MetS. METHODS: Twenty one healthy middle-aged males and 21 with MetS were distributed into four groups: MetS exercise (ME), MetS control (MC), Healthy exercise (HE) and healthy control (HC). Both ME and HE, followed a 6-week aerobic training program (3 sessions/week). Digit Span memory test and blood sampling were conducted pre training, post training and also following a six weeks detraining. Data were analyzed using spearman, pearson and repeated measure ANOVA tests. RESULTS: Baseline serum BDNF level was positively correlated with waist circumference (r=0.383, P=0.012) and showed significant elevation in MetS compared with healthy subjects (1101.66±61.34 vs. 903.72±46.57 pg/mL, P=0.014). After aerobic exercise BDNF level significantly increased in HE, but decreased in ME group (P=0.001). Both short and mid term memory significantly increased (P<0.05) only in HE group. CONCLUSION: Exercise induced cognitive improvement might be mediated via BDNF-linked mechanisms in healthy people. However, the health status of individuals should be considered.

Effects of aerobic exercise training on visceral fat and serum adiponectin concentration in ovariectomized rats.

OBJECTIVE: The aim of this experimental study was to investigate the effects of exercise training on visceral fat and adiponectin levels in ovariectomized (OVX) rats. METHOD: Female Wistar rats were divided into OVX (n = 20) and sham-operated control (SHAM; n = 8) groups. OVX rats were subdivided into a sedentary (OVX-SED; n = 10) and an exercise (OVX-EX; n = 10) group. The exercise consisted of 8 weeks of aerobic exercise (26 m/min, 5 days/week, 60 min/day, 10% slope). RESULTS: In OVX rats, body weight was 21% greater (255.2 +/- 9.31 vs. 211.63 +/- 3.23; p < 0.01) and visceral fat was 29% greater (10.87 +/- 0.66 vs. 8.43 +/- 0.45; p < 0.05) than in SHAM rats. After training, visceral fat was 20% lower in OVX-EX rats than in OVX-SED rats (8.72 +/- 0.46 vs. 10.87 +/- 0.66; p < 0.05). After 8 weeks of running on the treadmill, levels of serum glucose, insulin and serum adiponectin, and the homeostasis model assessment of insulin resistance were not changed significantly in the OVX-EX group. CONCLUSION: These results suggest that 8-week exercise training induces a decrease in visceral fat, and this reduction without weight loss does not change serum adiponectin levels and insulin sensitivity in ovariectomized rats.

Response of salivary peroxidase to exercise intensity.

Oral peroxidase, one of the most important salivary antioxidant enzymes, is subjected to alternation due to various body conditions. The aim of this study was to assess the effect of exercise intensity on salivary peroxidase activity. Using a randomized design, ten healthy male university students (mean age, 23.22; s (x) = 2.34 years) completed treadmill runs with initial velocity 6.73 km/h at the rate of 1.58 km/h increase every 3 min until exhaustion. Unstimulated whole saliva collected over a 5-min period in pre-weighed tubes before, immediately after exercise, and 1 h after exercise was analyzed for total protein and saliva peroxidase activity. The saliva flow rate ranged from 0.08 to 1.40 ml min(-1) at rest and was not significantly affected by the exercise. Peroxidase activity in each sample was measured using 4-amino antipyrine as substrate. In the incremental exhaustion run and also at 75% VO(2max), the secretion rates of peroxidase increased. No significant changes in saliva flow rate were observed in any treadmill run. Treadmill runs at 75% VO(2max) and to exhaustion increased the activity of peroxidase immediately after exercise which decreased after 1 h. It was concluded that short-duration, high-intensity exercise increases the activity rate of peroxidase despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic pituitary adrenal axis.