@article {Tuan11, author = {T-C Tuan and T-G Hsu and M-C Fong and C-F Hsu and K K C Tsai and C-Y Lee and C-W Kong}, title = {Deleterious effects of short-term, high-intensity exercise on immune function: evidence from leucocyte mitochondrial alterations and apoptosis}, volume = {42}, number = {1}, pages = {11--15}, year = {2008}, doi = {10.1136/bjsm.2006.029314}, publisher = {British Association of Sport and Excercise Medicine}, abstract = {Background: Although moderate exercise can benefit health, acute and vigorous exercise may have the opposite effect. Strenuous exercise can induce alterations in the physiology and viability of circulating leucocytes, which have a causal relationship with exercise-induced immune distress.Objectives: To investigate the use of mitochondrial transmembrane potential (MTP), a functional marker of the energy and viability status of leucocytes, for monitoring the immunomodulating effects of short-term, high-intensity exercise.Methods: 12 healthy volunteers with a mean Vo2max of 70.4 ml/kg/min carried out 3 consecutive days of high-intensity exercise (85\% of Vo2max for 30 min every day). Blood samples were collected at multiple time points immediately before and after each exercise session and at 24 and 72 h after the completion of exercise. Leucocyte MTP, apoptosis and circulatory inflammation markers were measured by flow cytometry and enzyme-linked immunosorbent assays.Results: MTP of peripheral blood leucocytes had declined immediately after the first exercise session and remained subnormal 24 h later. It did not normalise until 72 h after exercise. The sequential changes in MTP were consistent among the three leucocyte subpopulations (polymorphonuclear neutrophils, lymphocytes and monocytes) and were significant (p\<0.05). Leucocytes displayed a gradual and incremental change in their propensity for apoptosis during and after exercise. Similarly, plasma concentrations of tumour necrosis factor-α and soluble Fas ligand were raised during the exercise sessions and had not normalised by 72 h after the completion of exercise. Correlation between changes in leucocyte MTP and plasma concentrations of tumour necrosis factor-α and soluble Fas ligand was variable, but significant for polymorphonuclear neutrophils and lymphocytes (p\<0.05).Conclusions: Short-term, high-intensity exercise can lead to a significant and prolonged dysfunction of the mitochondrial energy status of peripheral blood leucocytes, which is accompanied by an increased propensity for apoptosis and raised pro-inflammatory mediators. These results support the immunosuppressive effects of excessive exercise and suggest that MTP is a useful marker of these effects.}, issn = {0306-3674}, URL = {https://bjsm.bmj.com/content/42/1/11}, eprint = {https://bjsm.bmj.com/content/42/1/11.full.pdf}, journal = {British Journal of Sports Medicine} }