Exhaustive Exercise Session Research Articles

English

The aim of the current study was to verify the effect of N-acetyl cysteine (NAC) supplementation on markers of oxidative stress and inflammatory response during a single session of exhaustive exercise. In a randomized placebo-controlled double-blind clinical trial, thirty healthy, untrained young males and females with a mean age of 21.33±2.39 years, weight of 59.63± 9.24 kg and height of 166.20±10.15 cm were selected and divided into 2 groups. Before starting the supplementation, blood samples were collected from all the participants. The next blood samples were collected just before the exercise started, immediately after the exhaustive exercise and after one hour of rest. Malondialdehyde (MDA), total antioxidative capacity (TAC), CRP, BMI and Vo2 max were determined. A significant increase was observed in MDA and CRP levels during the experiment in the placebo group. But in the treated group, the concentrations remained the same throughout the experiment. The TAC levels were significantly raised in the samples collected after NAC supplementation as compared to the placebo group. No changes were observed in the time to fatigue. Results of the current study suggest that oral consumption of n-acetyl cysteine for 24 h before a single bout of an exhaustive physical exercise could significantly reduce the harmful effects of oxidative stress. Key words: N-acetyl cysteine, oxidative stress, exhaustive exercise, reactive oxygen species, time to fatigue.

Toll-like receptor expression is altered by stress of intense physical conditioning (135.28)

Abstract Periods of intense physical training are associated with an increased incidence of infection. We hypothesize that the TLR pathways involved in the initial response to multiple pathogens are compromised during intense physical exercise stress. In order to test this hypothesis, eight male collegiate wrestlers participated in one month of intense physical conditioning stress. Blood was collected at rest both before and after a 1 month period of intense exercise, and after completing a single 90 minute session of exhaustive exercise. TLR receptor pathway expression was assessed by microarray. The results showed that 1 month of intense exercise conditioning decreased expression of genes that may be important in antiviral defense (IFN-alpha, TLR3, PKRKA, SARM1), and inflammatory response (TNFSRF, PTGS2, REL). Ninety minutes of intense exercise decreased IFN-gamma and IRF1, but expression of TLR pathways associated with anti-bacterial defense increased (TLR5, TIRAP, PGLYRP2, LY86). These findings are consistent with epidemiological data suggesting an increased incidence of respiratory viral infections during periods of intense physical exercise stress. The results also implicate several genes important in inflammation, and further research is needed to determine whether these genes play a significant role in the recently reported anti-inflammatory effects of repeated exercise.

Exercise stress alters the percentage of splenic lymphocyte subsets in response to mitogen but not in response to interleukin-1

Results of previous work from this laboratory demonstrated that reduced murine splenic lymphocyte proliferation in response to Concanavalin A (Con A) is associated with acute exercise stress. The present study was conducted to determine whether the stress of physical work further affects the expression of splenic lymphocyte phenotypes following in vitro stimulation by the T-cell mitogen, Con A, and also by interleukin-1 (IL1). Mice in this study were assigned to one of five treatment conditions. Two groups of mice were exposed only to the noise and vibration of a treadmill for 8 weeks; one of these groups was given an acute exhaustive run. Three groups of mice were exposed to 8 weeks of treadmill training: one group was sacrificed immediately after training, a second group was sacrificed 72 h after training, and a third group was rested for 72 h and then given an acute exhaustive run. There was a significant effect of stimulation by Con A on the perentage of splenic lymphocytes positive for Thy 1.2, Lyt-2, L3T4, and goat anti-mouse Ig, regardless of treatment condition. Acute exercise, however, affected the magnitude of the response. There was a significantly greater increase in the percentage of Thy1.2 + and, especially of, Lyt-2 + cells in stimulated splenic lymphocytes from untrained mice given an exhaustive exercise session compared with controls and with trained mice. There was no significant effect of the addition of IL1 to any culture, irrespective of treatment condition. These results suggest that reduced mitrogenesis after acute exercise stress exposure may be related to the increased appearance of Lyt-2 + (T suppressor) cells.

Fast axonal transport of labeled proteins in motoneurons of exercise-trained rats

In this study, the fast orthograde axonal transport of radiolabeled proteins was measured to determine the effects of endurance-running training on transport velocity and amounts of transported proteins in rat sciatic motoneurons. Female rats were subjected to a progressive running-training program for 10-12 wk. Twenty-four hours after the last training session, rats underwent right L4-L5 dorsal root ganglionectomy. The next day, 20 microCi of [3H]leucine was injected bilaterally in the vicinity of the motoneuronal cell bodies supplying the sciatic nerve, to study axonal transport parameters. Results showed that peak and average transport velocities of labeled proteins were significantly (P less than 0.05) increased by 22 and 29%, respectively, in the deafferented nerves of the runners as compared with controls. Moreover, the amount of total transported protein-bound radioactivity was increased in both left (40%) and right (37%) sciatic nerves of the runners. An exhaustive exercise session reduced (P less than 0.05) peak displacement (8%) and total transported protein-bound radioactivity (36%) in the sciatic nerves of control rats, whereas no changes were noticed in trained animals. The data suggest that chronic endurance running induces significant adaptations in the fast axonal transport of labeled proteins.