Effects of short-duration and long-duration exercise on lipoprotein(a)

Purpose: Most studies that use either a single exercise session, exercise t raining, or a cross-sectional design have failed to find a relationship bet ween exercise and plasma lipoprotein(a) [Lp(a)] concentrations. However, a few studies investigating the effects of longer and/or more strenuous exerc ise have shown elevated Lp(a) concentrations, possibly as an acute-phase re actant to muscle damage. Based on the assumption that greater muscle damage would occur with exercise of longer duration, the purpose of the present s tudy was to determine whether exercise of longer duration would increase Lp (a) concentration and creatine kinase. (CK) activity more than exercise of shorter duration. Methods: Ten endurance-trained men (mean +/- SD: age, 27 +/- 6 yr; maximal oxygen consumption [(V)over dotO(2max)], 57 +/- 7 mL(.)kg (-1) min(-1)) completed two separate exercise sessions at 70% (V)over dotO( 2max). One session required 900 kcal of energy expenditure (60 +/- 6 min), and the other required 1500 kcal (112 +/- 12 min). Fasted blood samples wer e taken immediately before (0-pre), immediately after (0-post), 1 d after ( 1-post), and 2 d after (2-post) each exercise session. Results: CK activity increased after both exercise sessions (mean +/- SE; 800 kcal: 0-pre 55 +/ - 11, 1-post 168 +/- 64 U(.)L(-1.)min(-1); 1500 kcal: 0-pre 51 +/- 5, 1-pos t 187 +/- 30, 2-post 123 +/- 19 U(.)L(-1.)min(-1); P < 0.05). However, medi an Lp(a) concentrations were not altered by either exercise session (800 kc al: 0-pre 5.0 mg(.)dL(-1), 0-post 3.2 mg(.)dL(-1), 1-post 4.0 mg(.)dL(-1), 2-post 3.4 mg(.)dL(-1); 1500 kcal: 0-pre 5.8 mg(.)dL(-1), 0-post 4.3 mg(.)d L(-1), 1-post 3.2 mg(.)dL(-1), 2-post 5.3 mg(.)dL(-1)). In addition, no rel ationship existed between exercise-induced changes in CK activity and Lp(a) concentration (800 kcal: r = -0.26; 1500 kcal: r = -0.02). Conclusion: The se results suggest that plasma Lp(a) concentration will not increase in res ponse to minor exercise-induced muscle damage in endurance-trained runners.