Deleterious effects of short-term, high-intensity exercise on immune function: evidence from leucocyte mitochondrial alterations and apoptosis

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 VO 2 MAX of 70.4 ml/kg/min carried out 3 consecutive days of highintensity exercise (85% of VO 2 MAX 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-a 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-a 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.

Moderate intensity physical training accelerates healing of full-thickness wounds in mice

“…Cytokines systemically released during physical training could influence the wounds locally. It is possible that the anti-inflammatory cytokine balance experienced by the animals trained at moderate intensity (27) would be able to reduce the amount of inflammatory cells in the granulation tissue. In fact, animals that trained at 80% VO 2max (H/E lesion and H/E euthan ) also presented a reduction of the inflammatory infiltrate in the granulation tissue.…”

“…In fact, animals that trained at 80% VO 2max (H/E lesion and H/E euthan ) also presented a reduction of the inflammatory infiltrate in the granulation tissue. On the other hand, strenuous physical training may induce inflammatory reactions and immune disturbances because of the increased concentrations of pro-inflammatory mediators (27).…”

Effect of 6-day intense Kendo training on lymphocyte counts and its expression of CD95

“…However, the isolated CD95 measurement is not a marker of apoptotic cells. A few prior reports described that short-term high-intensity repeated exercise induced lymphocyte apoptosis assessed by Annexin V or DNA fragmentation (Hsu et al 2002;Tuan et al 2007). The alteration of apoptosis may depend on the exercise intensity and the trained status of subjects (Hsu et al 2002;Mooren et al 2002).…”

“…Previous reports have described that short-term high-intensity repeated exercise increased lymphocyte apoptosis indices (Hsu et al 2002;Tuan et al 2007). However, those studies did not examine lymphocyte count alteration.…”

Effects of three consecutive days exercise on lymphocyte DNA damage in young men

“…Furthermore, high-intensity repeated exercise decreases lymphocyte counts (Malm et al 2004). Shortterm repeated exercise increases oxidative stress and lymphocyte-apoptosis indices (Hsu et al 2002;Shing et al 2007;Tuan et al 2007). Consequently, decreased lymphocyte counts after short-term repeated exercise might also result from increased oxidative DNA damage and/or lymphocyte apoptosis.…”