title: Immune response to changes in training intensity and volume in runners.
abstract: We examined the acute and chronic effects of changes in training volume and intensity on the blood lymphocyte percentages and immunoglobulin levels in runners. Twelve runners participated in four 10-d phases of low volume/low intensity (LV/LI), high volume/low intensity (HV/LI), or high volume/high intensity (HV/HI) running. Subjects were assigned to one of two different training group orders: 1) LV/LI, HV/LI, LV/LI, HV/HI; or 2) LV/LI, HV/HI, LV/LI, HV/LI. Venous blood was drawn at rest on days 1, 4, and 7; and 5 min post-exercise on days 1 and 7 of each 10-d phase. Lymphocyte subsets were determined by flow cytometry for CD3+, CD4+, CD8+, and HLA-DR+. IgG, and IgM levels were obtained by ELISA analysis. Immunoglobulin, CD8+ and HLA-DR+ levels, and pre-exercise plasma cortisol concentrations were not significantly affected by alterations in volume or intensity. A transient decrease (P < 0.05) was observed in CD4+ and the CD4/CD8 ratio 5 min post-exercise during the HV/LI and HV/HI phases. Results indicate that the exercise-induced lymphocyte subset reduction is transient and suggest that it is more dependent upon training intensity than volume, and the training order of exposure to the high-intensity stimulus may determine the magnitude of subsequent responses.
mesh_terms: D000293:Adolescent; D000328:Adult; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins / Q000097:blood*; D018655:Lymphocyte Count; D008297:Male; D010806:Physical Education and Training; D012420:Running / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D006684:HLA-DR Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D006854:Hydrocortisone