A treadmill control protocol combining nonlinear, equally smooth increases in speed and gradient: Exercise testing for subjects with gait and exercise limitations
✍ Scribed by L.P. Jamieson; K.J. Hunt; D.B. Allan
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 833 KB
- Volume
- 30
- Category
- Article
- ISSN
- 1350-4533
No coin nor oath required. For personal study only.
✦ Synopsis
Incremental exercise testing with a linear increase in work rate is the recommended method for clinical exercise testing. A recent protocol (A), incorporating a linear increase in speed and a nonlinear increase in gradient, has been developed which addresses some limitations of traditional testing methods. It does not account for those with an impaired gait pattern. We propose and assess a novel protocol (B) incorporating nonlinear increases in both speed and gradient.
We theoretically develop a new treadmill control protocol (B), determine oxygen uptake response linearity, initial metabolic rate and cardiopulmonary response parameters (peak oxygen uptake, lactate threshold, dynamic O 2 cost) and compare the outcome measures with two previously verified IET protocols (A and C (constant speed with linear increase in gradient)). Feasibility and outcomes were explored with a subject with incomplete spinal cord injury.
The average initial metabolic rate ( VO 2 ) was substantially lower during protocol A (0.49 (±0.12) l min -1 ) and protocol B (0.52 (±0.05) l min -1 ) than during protocol C (1.35 (±0.04) l min -1 ). The average linearity of the VO 2 response during protocols A and B (correlation co-efficients 0.97 (±0.00) and 0.95 (±0.02), and co-efficients of determination 0.94 (±0.01) and 0.91 (±0.02), respectively) were higher than during protocol C (correlation co-efficient 0.91 (±0.02) and co-efficient of determination 0.84 (±0.02)). The average dynamic O 2 cost for protocol C (6.53 (±0.46) ml min -1 W -1 ) was lower than that of protocol A (10.02 (±1.16) ml min -1 W -1 ) and protocol B (10.03 (±0.91) ml min -1 W -1 ). No differences were found in these parameters between protocols A and B.
The new protocol B performs better than protocol C and is comparable with protocol A. When testing subjects with an impaired gait pattern, it may be advantageous to use the new protocol B due to the gradual increases in both speed and gradient throughout the test.