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 Stockholms Marathon (1979), 18 male subjects underwent a test to determine the relationship between treadmill runningvelocity and blood lactate accumulation. The velocity at which a blood lactateaccumulation of 4 mmol/l occurred was referred to as the VOBLA. The m. vastus lateralis was biopsied and muscle fiber type distribution ( slow twitch, ST) and capillary density determined. With marathon running velocity (VM) as the dependent variable, multiple regression analysis showed that VOBLA accounted for 92 of the variation in VM, and VOBLA 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 closely related to VOBLA 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. Verf.-Referat