EFFECT OF EXERCISE TRAINING DOSE AND INTENSITY ON LIPOPROTEINS AND LIPOPROTEIN SUBFRACTIONS

Abstract

Increased levels of physical activity are clearly related to reduced risk of CVD. One possible mechanism is through improvements in lipoproteins. However, the optimal exercise stimulus is unknown as there are no dose-response studies. PURPOSE: We investigated the effects of training dose and intensity on lipoproteins and their subfractions. METHODS: Eightyfour males and females, aged 40–65, who were overweight/obese (BMI 25–35 kg/m2) with dyslipidemia (LDL-C: 130–190 OR HDL-C < 40) were randomized to a control or one of three exercise groups: low dose/moderate intensity (12 miles/wk at 50% peak VO2), low dose/vigorous intensity (12 miles/wk at 75%), high dose/vigorous intensity (20 miles/wk at 75%). Training included a 2–3 month ramp period plus 6 months of exercise at the assigned intensity/dose. RESULTS: Exercise did not effect total or LDL-C. High dose exercise significantly (P < 0.05) decreased small LDL's, LDL particle concentration, average LDL size, triglycerides, and total VLDL-TG and increased large HDL's, average HDL size, and total HDL's, with a tendency (P < 0.06) for reduced large VLDL's compared to controls. Low dose exercise was less beneficial. The high dose-vigorous group had a larger improvement than low dose-vigorous on 10 of 11 variables and the low dose had a better effect than the control on all 11 variables - clear evidence of a dose-response effect. CONCLUSION: The data show that, for individuals with mild to moderate dyslipidemia, high dose exercise has widespread beneficial effects on lipoproteins. However, few of these benefits would be detected by a typical lipid panel. The data also demonstrate a clear dose-response effect. The effects of exercise intensity appear to be much less important than exercise dose.