Table 2.
Physiologic data from the pilot feasibility study
| Parameter |
Maximal incremental |
Constant 80% Ẇmax |
Constant 90% Ẇ max |
||
|---|---|---|---|---|---|
| Visit 1 | Visit 2 | Visit 3 | Visit 2 | Visit 3 | |
| Time (seconds) | 575 (170) | 599 (221) | 713 (267) | 308 (180) | 388 (235) |
| Speed (mph) | 2.7 (1.0) | 2.2 (0.7) | 2.2 (0.7) | 2.6 (0.8) | 2.6 (0.8) |
| Grade (%) | 8.2 (1.6) | 8.4 (1.4) | 8.4 (1.4) | 8.1 (1.5) | 8.1 (1.5) |
| Ẇ (watts) | 80 (38) | 67 (29) | 68 (30) | 77 (34) | 77 (34) |
| V̇O2 max (L/min) | 1.34 (0.36) | 1.28 (0.35) | 1.26 (0.37) | 1.41 (0.39) | 1.40 (0.43) |
| V̇O2 max (% reference) | 86 (23) | 81 (22) | 79 (21) | 96 (29) | 95 (26) |
| V̇O2 max (mL/kg/min) | 16.7 (4.2) | 15.2 (2.9) | 14.9 (2.9) | 17.6 (4.3) | 17.3 (3.9) |
| V̇O2/Ẇ (mL/min/watt) | 10.7 (4.3) | – | – | – | – |
| V̇O2θ (L/min) | 0.98 (0.17) | – | – | – | – |
| V̇O2 (6′–3′) (L/min) | – | 0.05 (0.08) | 1.22 (0.41) | 0.13 (0.03) | 0.12 (0.08) |
| V̇CO2 max (L/min) | 1.29 (0.40) | 1.22 (0.37) | 1.22 (0.41) | 1.41 (0.51) | 1.35 (0.50) |
| fc max (/min) | 119 (17) | 113 (14) | 112 (13) | 122 (17) | 119 (13) |
| fc max (% reference) | 80 (13) | 75 (11) | 74 (11) | 81 (10) | 79 (8) |
| V̇E max (L/min) | 43.7 (11.6) | 44.2 (13.2) | 45.1 (15.4) | 46.8 (14.6) | 48.4 (17.4) |
| V̇E max/MVV (%) | 77 (18) | 68 (16) | 69 (20) | 85 (11) | 87 (11) |
| RPE (Borg 6–20) | 15.0 (1.8) | – | – | 14.8 (2.1) | 15.1 (2.2) |
| Dyspnea (VAS 0–100) | 50 (20) | – | – | 52 (28) | 58 (28) |
Note: Values are mean (± standard deviation).
Abbreviations: Ẇ, work rate; V̇O2, oxygen uptake; V̇O2(6′–3′), change in oxygen uptake between the third and sixth minutes of the test (oxygen uptake drift); V̇CO2, carbon dioxide output, fc, heart rate; V̇E, minute ventilation; MVV, maximum voluntary ventilation; RPE, rating of perceived exertion (on original Borg 6–20 scale); VAS, visual analog scale (with terminal anchors of “not at all breathless” and “extremely breathless”).