Influence of pacing strategy on oxygen uptake during treadmill middle-distance running.

The oxygen uptake (VO2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal VO2 (VO2max) in male middle-distance runners with a high VO2max (i.e., > 65 ml x kg (-1) x min (-1)). We therefore investigated whether the VO2 attained was influenced by the pacing strategy adopted. Eight male middle-distance runners (age 25.8 +/- 3.3 years; height 1.78 +/- 0.10 m; mass 67.8 +/- 4.7 kg) with a personal best 800-m time of 112.0 +/- 3.3 s volunteered to participate. Subjects undertook a speed ramped progressive test to determine VO2max and three 800-m pace runs to exhaustion all in a randomised order. The three 800-m pace runs included constant speed, acceleration, and race simulation runs. Oxygen uptake was determined throughout each test using 15-s Douglas bag collections. Following the application of a 30-s rolling average, the highest VO2 during the progressive test (i.e., VO2max) and the highest VO2 during the 800-m pace runs (i.e., VO2peak) were compared. For the eight runners, VO2max was 67.2 +/- 4.3 ml x kg (-1) x min (-1) x VO2peak was 60.1 +/- 5.1 ml x kg (-1) x min (-1), 61.1 +/- 5.2 ml x kg (-1) x min (-1), and 62.2 +/- 4.9 ml x kg (-1) x min (-1), yielding values of 89.3 +/- 2.4 %, 90.8 +/- 2.8 %, and 92.5 +/- 3.1 % VO2max for the constant speed, acceleration and race simulation runs, respectively. Across runs, repeated measures ANOVA revealed a significant effect (p = 0.048). Trend analysis identified a significant linear trend (p = 0.025) with the % VO2max attained being higher for the acceleration run than the constant speed run, and higher still for the race simulation run. These results demonstrate that in middle-distance runners a) pacing strategy influences the VO2 attained, with a race simulation run elevating the VO2 attained compared with other pacing strategies, and b) regardless of pacing strategy the VO2 attained in an 800-m pace run on a treadmill is less than VO2max.