No abstract

Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.

Aim:  In recent years, blood sphingolipids attracted much attention and have been implicated in both pathophysiology and prevention of cardiovascular diseases and insulin resistance. However, factors affecting concentration and metabolism of sphingolipids in blood remain poorly recognized. We have previously found that exercise alters skeletal muscle sphingolipid metabolism. This finding prompted us to examine whether physical activity induces similar effects in blood. Methods:  Twenty healthy male patients were assigned to either untrained (UT, n = 10) or endurance trained (ET, n = 10) group. The patients performed either a 30 (UT group) or 60 (ET group) min exercise on a cycloergometer at a workload corresponding to 70% of V̇O2max. Blood samples were taken just before exercise, after 30 and 60 (ET group only) min of pedalling and following a 30‐min rest. Results:  ET patients were characterized by higher basal plasma sphingosine‐1‐phosphate (S1P) concentration and decreased content of sphingosine, S1P, sphinganine‐1‐phosphate (SA1P) and ceramide in erythrocytes. In ET group, plasma concentrations of all measured sphingolipids remained stable both during and after exercise. On the other hand, in UT patients, the post‐exercise levels of S1P and SA1P were markedly higher compared with the baseline values and this effect was accompanied by decreased erythrocyte ceramide content. Conclusion:  It is likely that single bout of exercise and endurance training enhances production and release of S1P by erythrocytes. We speculate that exercise‐induced increase in plasma S1P concentration might be one of the mechanisms underlying beneficial effects of physical activity on cardiovascular health and insulin sensitivity.

PurposeSphingosine-1-phosphate (S1P) regulates cardiovascular function and plays an important role in muscle biology. We have previously reported that cycling exercise increased plasma S1P. Here, we investigated the effect of exercise duration and intensity on plasma and skeletal muscle S1P levels.MethodsIn the first experiment, 13 male athletes performed a 60-min exercise at 65 % of VO2max and a graded exercise until exhaustion on a rowing ergometer. Samples of the venous blood were taken, and plasma, erythrocytes and platelets were isolated. In the second experiment, ten male moderately active subjects performed three consecutive periods of one-leg knee extension exercise (at 25, 55 and 85 % of the maximal workload). Muscle biopsies and blood samples from the radial artery and femoral veins were taken.ResultsUnder basal conditions, S1P was released from the leg, as its concentration was lower in the arterial than in the venous plasma (p < 0.01). Exercise until exhaustion increased plasma S1P and sphinganine-1-phosphate (SA1P) concentration (p < 0.05), whereas moderate-intensity exercise elevated only SA1P (p < 0.001). Although knee extension increased muscle S1P content (p < 0.05), it was not released but taken up across the leg during exercise. However, sphingosine was released from both working and resting leg at the highest workload (p < 0.05).ConclusionsPlasma S1P concentration is elevated only by high-intensity exercise which results, at least in part, from increased availability of sphingosine released by skeletal muscle. In addition, exercise markedly affects S1P dynamics across the leg. We speculate that S1P may play an important role in adaptation of skeletal muscle to exercise.Electronic supplementary materialThe online version of this article (doi:10.1007/s00421-014-3080-x) contains supplementary material, which is available to authorized users.

Background: Systematic physical activity can permanently prevent disadvantageous developments in the human body. This is very important especially for women, for whom the maintenance of a lean body in good shape is sometimes a primary consideration. However, in most cases, this activity is taken randomly and does not produce the desired effects such as reducing body fat. The purpose of the study was to evaluate changes in female body composition induced by 12 weeks of swimming training compared to sedentary controls. Methods: Training sessions occurred three times per week (60 min/session). Height, body mass, and waist/hip circumference and waist/hips ratio (WHR) were measured. Body cell mass (BCM), total body water (TBW), extracellular (ECW) and intracellular water (ICW), fat mass (FM), lean mass (FFM), and muscle mass (MM) were measured using bioelectrical impedance (pre/post). Results: Training elicited decreases in hip circumference and increase in WHR. No changes were recorded in BCM, TBW, ECW, ICW, FM, FFM, and MM. Controls experienced decreases in values of BCM, ICW, and MM and increases in ECW. Conclusion: The applied swimming training did not significantly affect the body composition parameters. Inactivity also triggered a tendency toward unhealthy movement of water from the intracellular to extracellular space.