Article

Cardiorespiratory fitness assessment and training among manual
wheelchair (MW) users are predominantly done with an arm-crank ergometer.
However, arm-crank ergometer biomechanics differ substantially from MW propulsion
biomechanics. This study aimed to quantify cardiorespiratory responses resulting
from speed and slope increments during MW propulsion on a motorized treadmill and
to calculate a predictive equation based on speed and slope for estimating peak
oxygen uptake (VO2peak) in MW users. METHODS: In total, 17 long-term MW users
completed 12 MW propulsion periods (PP), each lasting 2min, on a motorized
treadmill, in a random order. Each PP was separated by a 2-min rest. PPs were
characterized by a combination of 3 speeds (0.6, 0.8 and 1.0m/s) and 4 slopes (0
degrees , 2.7 degrees , 3.6 degrees and 4.8 degrees ). Six key cardiorespiratory
outcome measures (VO2, heart rate, respiratory rate, minute ventilation and tidal
volume) were recorded by using a gas-exchange analysis system. Rate of perceived
exertion (RPE) was measured by using the modified 10-point Borg scale after each
PP. RESULTS: For the 14 participants who completed the test, cardiorespiratory
responses increased in response to speed and/or slope increments, except those
recorded between the 3.6o and 4.8o slope, for which most outcome measures were
comparable. The RPE was positively associated with cardiorespiratory response
(rs>/=0.85). A VO2 predictive equation (R2=99.7%) based on speed and slope for
each PP was computed. This equation informed the development of a future testing
protocol to linearly increase VO2 via 1-min stages during treadmill MW
propulsion. CONCLUSIONS: Increasing speed and slope while propelling a MW on a
motorized treadmill increases cardiorespiratory response along with RPE. RPE can
be used to easily and accurately monitor cardiorespiratory responses during MW
exercise. The VO2 can be predicted to some extent by speed and slope during MW
propulsion. A testing protocol is proposed to assess cardiorespiratory fitness
during motorized MW propulsion.
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Langue : ANGLAIS