Purpose: The purpose of this study was to examine the influence of a 12-wk exercise training program on inflammatory cytokine and C-reactive protein (CRP) concentrations. A secondary purpose was to determine whether training-induced changes in cytokines and CRP were influenced by age.
Methods: Twenty-nine younger (18-35 yr) and 31 older (65-85 yr) subjects were assigned to young physically active (YPA, N = 15; 25 ± 5 yr), young physically inactive (YPI, N= 14; 25 ± 4.7 yr), old physically active (OPA, N = 14; 71 ± 4 yr), or old physically inactive (OPI, N = 17; 71 ± 4 yr) groups. The inactive groups completed 12 wk (3 d·wk−1) of aerobic and resistance exercises, and the physically active control groups continued their normal exercise programs. Blood samples were collected before and after the 12-wk period, and the concentrations of serum CRP, plasma interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) were determined using separate ELISA.
Results: Control (YPA and OPA) estimated V˙O2max was unchanged. Exercise training increased estimated V˙O2max an average of 10.4% and increased strength by an average of 38.1% in both PI groups. Serum CRP decreased with training (YPI and OPI) groups and was not different from the YPA and OPA groups after training. Plasma IL-6 and IL-1β did not change, whereas TNF-α was higher than YPI and YPA at baseline and after the intervention period.
Conclusion: These results support the use of combined aerobic/resistance training as a modality to reduce the risk of cardiovascular disease development as defined by a decrease in serum CRP concentration in healthy humans.
1Department of Kinesiology, Louisiana State University, Baton Rouge, LA; 2Wastl Human Performance Laboratory, 3Department of Foods and Nutrition, 4Department of Statistics, and 5Bindley Biosciences Center, Basic Medical Sciences, Purdue University, West Lafayette, IN; and 6Department of Health and Human Performance, University of Houston, Houston, TX
Address for correspondence: Laura K. Stewart, Ph.D., Division of Exercise Physiology, Department of Kinesiology, Louisiana State University, 112 Long Fieldhouse, Baton Rouge, LA 70803-2401; E-mail: Stewart6@lsu.edu.
Submitted for publication January 2006.
Accepted for publication May 2007.