EFFECTS OF SHORT-DURATION AND LONG-DURATION EXERCISE ON LIPOPROTEIN(a)[Lp(a)] 31

Abstract

Most studies employing either a single session of exercise, exercise training, or a cross-sectional design have failed to find a relationship between exercise and plasma concentrations of lipoprotein(a)[Lp(a)]. However, a few studies examining the effects of long-duration exercise have shown elevated Lp(a), possibly as an acute phase response to muscle damage. Assuming that greater muscle damage occurs with exercise of longer duration, the purpose of this study was to compare Lp(a) concentration and creatine kinase (CK) activity following both short-duration and long-duration treadmill running. Ten men (age: 26.7±6.1; ˙VO2max: 56.3±6.6 mL·kg-1·min-1, mean±SD) completed two separate exercise sessions at 70% ˙VO2max. One session required 800 kcal of energy expenditure (SHORT: 60±6 min) while the other required 1500 kcal (LONG: 112±12 min). Fasted blood samples were obtained immediately before (0-pre), immediately after(0-post), 1 day after (1-post), and 2 days after(2-post) both exercise sessions. ANOVA revealed significant elevations in CK activity following both exercise sessions (SHORT: 0-pre 55±36, 1-post 168±201 U·L-1; LONG: 0-pre 51±15, 1-post 187±94, 2-post 123±59 U·L-1, p<0.05). However, Friedman ANOVA by ranks showed no significant change in Lp(a) following either session (SHORT: 0-pre 5.0, 0-post 3.2, 1-post 4.0, 2-post 3.4 mg·dL-1; LONG: 0-pre 5.8, 0-post 4.3, 1-post 3.2, 2-post 5.3 mg·dL-1, median, p>0.05). Furthermore, Spearman's correlations showed no significant relationships between Lp(a) following exercise versus CK activity at 1-post (r=-0.13 at 0-post, -0.18 at 1-post, and-0.16 at 2-post, p>0.05). These results suggest that 1-2 hours of level treadmill exercise at 70% ˙VO2max can increase CK activity with no change in Lp(a) concentration.