Isometric strength, sprint power, and aerobic power in individuals with a spinal cord injury

This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging from C4/C5 to L5. Fiso was defined as the maximum force that could be exerted on the blocked rims of a stationary wheelchair ergometer. The estimation of P30 involved the measurement of the mean power during a 30-s all-out sprint test on the same wheelchair ergometer. VO2peak and POaer were determined as the peak oxygen uptake and highest sustained power output during a discontinuous progressive maximal exercise test on a motorized treadmill, while subjects used their own daily use wheelchair. Fiso ranged from 1.5 N.kg-1 (mean of both arms) in the group with quadriplegia to 3.4 N.kg-1 in the group with lowest-lesions, and P30 ranged from 0.5 to 1.5 W.kg-1 among the subjects. VO2peak ranged from 13.6 ml.kg-1.min-1 in the group with quadriplegia to 31.3 ml.kg-1.min-1 in the group with lowest-lesions, and POaer ranged from 0.4 to 1.1 W.kg-1. Strong positive relationships (r = 0.81-0.92) were demonstrated among all variables. Regression equations among variables were calculated: P30 = 0.51 Fiso - 0.18 (R2 = 0.75); POaer = 0.34 Fiso - 0.02 (R2 = 0.66); POaer = 0.67 P30 + 0.11 (R2 = 0.81); VO2peak = 6.52 Fiso + 4.15 (R2 = 0.76); VO2peak = 12.03 P30 + 7.43 (R2 = 0.77); VO2peak = 16.81 POaer + 6.44 (R2 = 0.84).(ABSTRACT TRUNCATED AT 250 WORDS)