Onset of Blood Lactate Accumulation and Marathon Running Performance

Abstract

This study was designed to examine the interrelationships among endurance running performance (marathon), the exercise intensity at which the “onset of blood lactate accumulation” (OBLA) occurs, training volume, and muscle fiber characteristics. In conjunction with Stockholm's Marathon (1979), 18 male subjects underwent a test to determine the relationship between treadmill running velocity and blood lactate accumulation. The velocity at which a blood lactate accumulation of 4 mmol × l^-1 occurred was referred to as the V_OBLA The m. vastus lateralis was biopsied and muscle fiber type distribution (% slow twitch, ST) and capillary density determined. With marathon running velocity (V_M) as the dependent variable, multiple regression analysis showed that V_OBLA accounted for 92% of the variation in V_M, and V_OBLA Plus training volume prior to the marathon accounted for 96% of this variation. All performance variables were positively correlated to% ST muscle fiber distribution (r 0.55-0.69) and capillary density (r = 0.52-0.63). Thus, marathon running performance was clpsely related to V_OBLA and to the ability to run at a pace close to that velocity during the race. These properties were in turn related to % ST, capillary density, and training volume.

Key words

prolonged exercise - lactate - muscle fiber type - anaerobic threshold