PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Physical exercise”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources

[Effect of sodium hydroxybutyrate on the ammonia level in the rat muscles under physical exercise].

The experiments on rats exposed to compulsory swimming have shown the normalizing effect of sodium hydroxybutyrate with respect to one of the biochemical indices of physical overwork: the ammonia level in cross-striated muscles. In control rats who had not received the drug, the swimming induced a significant (more than twofold) increase in the muscle tissue ammonia level, whereas animals preventively treated with sodium hydroxybutyrate (single administration or two-week course) demonstrated no ammonia accumulation. It is suggested that sodium hydroxybutyrate preventing the toxic effect of one of the end products of nitrogen metabolism may reduce afteraction of muscular overwork.

Ammonia↗

Carnitine and physical exercise.

Carnitine plays a central role in fatty acid (FA) metabolism. It transports long-chain fatty acids into mitochondria for beta-oxidation. Carnitine also modulates the metabolism of coenzyme-A (CoA). It is not surprising that the use of supplementary carnitine to improve physical performance has become widespread in recent years, although there is no unequivocal support to this practice. However, critical reflections and current scientific-based knowledge are important because the implications of reduced or increased carnitine concentrations in vivo are not thoroughly understood. Several rationales have been forwarded in support of the potential ergogenic effects of oral carnitine supplementation. However, the following arguments derived from established scientific observations may be forwarded: (i) carnitine supplementation neither enhances FA oxidation in vivo or spares glycogen or postpones fatigue during exercise. Carnitine supplementation does not unequivocally improve performance of athletes; (ii) carnitine supplementation does not reduce body fat or help to lose weight; (iii) in vivo pyruvate dehydrogenase complex (PDC) is fully active already after a few seconds of intense exercise. Carnitine supplementation induces no further activation of PDC in vivo; (iv) despite an increased acetyl-CoA/free CoA ratio, PDC is not depressed during exercise in vivo and therefore supplementary carnitine has no effect on lactate accumulation; (v) carnitine supplementation per se does not affect the maximal oxygen uptake (VO2max); (vi) during exercise there is a redistribution of free carnitine and acylcarnitines in the muscle but there is no loss of total carnitine. Athletes are not at risk for carnitine deficiency and do not have an increased need for carnitine. Although there are some theoretical points favouring potential ergogenic effects of carnitine supplementation, there is currently no scientific basis for healthy individuals or athletes to use carnitine supplementation to improve exercise performance.

Animals↗

Physical exercise in multiple sclerosis: supportive care or a putative disease-modifying treatment.

Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease affecting young adults and leading to considerable disability. For many years, patients have been advised to avoid physical activity. Today, however, an increasing number of studies have shown beneficial effects of exercise training in MS. It has been reported that such programs not only improve fitness parameters but can also enhance quality of life and beneficially affect some suggestive disability measures. Pilot studies even indicate a neuroprotective potential. This review summarizes the findings of the major clinical trials on exercise in MS. Possible biological effect mediators, such as neurotrophic factors or anti-inflammatory cytokines, will be discussed. Exercise management guidelines will be proposed and possible further research strategies are presented.

Exercise↗

Cardio-respiratory adaptation to physical exercise and hypoxia after a high-altitude expedition.

Seven young, male subjects were tested before and immediately after 6 weeks high-mountain expedition. Cardio-respiratory measurements were performed at rest and during standard physical excercise (10 min, 100 W) when breathing atmospheric air or hypoxic mixture (14% O2 in N2). After the expedition an increased V o2 max (16% an average) and diminished heart rate response to submaximal exercise were found. This was observed during air and hypoxic mixture breathing. There was significant increase in stroke volume and cardiac output during the exercise. No significant differences in ventilatory parameters were found nor at rest or during exercise under condition of breathing atmospheric air or hypoxic mixture. No changes in erythrocyte count or haemoglobin concentration in the blood were found. The physiological changes which developed during high-mountain expedition were more dependent on physical that hypoxic training.

Adaptation, Physiological↗

[The status of and developmental outlook for sports medicine and therapeutic physical exercise in Ukraine].

The sports medicine service in Ukraine, its structure, priority tasks, manpower potential, extent and quality of care-giving to sportsmen and those individuals engaged in physical culture over the period 1997-1998 are detailed. Case follow-up findings are submitted together with indices for medical and biological supplies to sportsmen. Ways for further improvement of the sports medicine service are outlined.

Exercise Therapy↗