LAUSR

The purpose of the present investigation was to assess the effects of whole-body exercise on anaerobic threshold in individuals with spinal cord injury (SCI). Maximal oxygen uptake (VO2max) and oxygen uptake at anaerobic threshold (AT) were measured before and after 6 months of hybrid functional electrical stimulation row training in 47 participants with SCI aged 19-63, neurological levels of injury C4-L1, American Spinal Injury Association Impairment Scale grades A-D, and time since injury at enrollment from 3 months to 40 years. Changes in VO2max differed with time since injury, with greater increases earlier post injury. The early chronic group (<3 years since injury; n=31) increased VO2max from 1.65 ± 0.54 L/min at baseline to 1.83 ± 0.66 L/min at 6 months (p<0.05), while the late chronic group (>3 years since injury; n=16) did not change (1.42 ± 0.44 at baseline to 1.47 ± 0.41 L/min at 6 months, p=0.36). Consistent with VO2max changes, AT increased in the early chronic group (1.03 ± 0.31 to 1.20 ± 0.40 L/min, p<0.05) and did not change in the late chronic group (0.99 ± 0.31 to 0.99 ± 0.26 L/min, p=0.92). Cumulative duration of exercise training was positively correlated to change in VO2max (r=0.475, p<0.05) but not to change in AT. Hybrid functional electrical stimulation row training is effective for increasing aerobic capacity and anaerobic threshold in individuals with spinal cord injury; however, these fitness benefits are only significant in individuals initiating the exercise intervention within three years of injury.