Table 1. Physiologic characteristics of 6 elite distance runners on the AlterG® Anti-Gravity treadmill® by velocity and different levels of body weight support. Data are means (±SD).
Variable 8 min·mile−1(3.35 m·s−1) pa 7 min·mile−1(3.84 m·s−1) p 6 min·mile−1(4.47 m·s−1) p 5 min·mile−1(5.36 m·s−1) p
VO2 (ml·kg−1·min−1)
0% BWS 35.00 (1.55) 41.35 (1.66) 48.27 (2.03) 59.43 (1.68)
20% BWS 24.30 (2.29) <.001 28.05 (2.02) <.001 33.93 (3.16) <.001 40.96 (4.73) <.001
40% BWS 23.67 (2.27) <.001 25.79 (2.42) <.001 31.31 (3.76) <.001 37.37 (4.76) <.001
Test for 20% vs. 40% BWS .724 .243 .204 .037
Net VO2 (ml·kg−1·min−1)
0% BWS 29.34 (1.85) 35.68 (1.93) 42.60 (1.72) 53.76 (1.51)
20% BWS 19.29 (1.61) <.001 23.04 (1.89) <.001 28.38 (3.03) <.001 35.96 (4.60) <.001
40% BWS 18.63 (2.15) <.001 20.75 (2.28) <.001 26.28 (3.65) <.001 32.36 (4.64) <.001
Test for 20% vs. 40% BWS .433 .086 .028 .536
RER (ratio of VCO2 / VO2)
0% BWS 0.85 (0.07) 0.89 (0.05) 0.91 (0.04) 1.00 (0.02)
20% BWS 0.80 (0.04) .033 0.88 (0.04) .478 0.88 (0.03) .159 0.90 (0.05) <.001
40% BWS 0.85 (0.06) .974 0.87 (0.04) .340 0.87 (0.03) .097 0.88 (0.03) <.001
Test for 20% vs. 40% BWS .045 .779 .746 .471
HR (Beats Per Min)
0% BWS 123.4 (6.2) 134.5 (5.3) 151.8 (6.0) 171.5 (5.6)
20% BWS 105.4 (7.7) .001 114.5 (8.0) <.001 126.3 (10.0) <.001 145.4 (13.7) <.001
40% BWS 101.4 (12.0) <.001 107.3 (10.1) <.001 117.9 (10.6) <.001 133.9 (12.2) <.001
Test for 20% vs. 40% BWS .484 .207 .138 .035
RPE (6-20)
0% BWS 9.3 (1.9) 11.7 (2.0) 14.3 (1.4) 16.8 (1.5)
20% BWS 8.3 (1.2) .251 10.0 (2.0) .058 12.3 (1.4) .024 14.3 (1.2) .005
40% BWS 7.3 (1.0) .024 9.2 (1.5) .005 12.0 (1.3) .009 14.2 (1.3) .003
Test for 20% vs. 40% BWS .251 .338 .700 .847