Physical Activity and Cardiovascular Health

Cardiovascular disease, when considered after the first year post-injury within the US Model Systems database, has been acknowledged as the leading cause of death in persons with SCI, supplanting respiratory complications and previous to that septicaemia (Whiteneck et al. 1992; DeVivo et al. 1999). Cardiovascular disease is currently also the leading cause of death in the able-bodied population. A recent review by Myers et al. (2007) noted that there is a significantly high prevalence of cardiovascular disease in persons with SCI with rates of symptomatic cardiovascular disease in SCI of 30–50% in comparison to 5–10% in the general able-bodied population. Physical activity interventions comprise a significant part of the strategy in dealing with cardiovascular disease and the reader is referred to our Cardiovascular Health and Exercise module for more information on this topic. The below section presents the specific evidence-based statements and bottom-line conclusions from that module related to physical activity.

Conclusion

Treadmill training

There is level 1b evidence (Millar et al. 2009) that BWSTT improves cardiac autonomic balance in persons with tetraplegia and paraplegia (with similar results for varying degrees of lesion level and severity).

There is level 4 evidence that BWSTT increases peak oxygen uptake and heart rate, and decreases the dynamic oxygen cost for persons with SCI.

There is level 4 evidence (Ditor et al. 2005a) that body-weight support treadmill training (BWSTT) improves cardiac autonomic balance in persons with incomplete tetraplegia.

There is level 4 evidence (de Carvalho and Cliquet 2005) that BWSTT can lead to improvements in cardiac autonomic balance in a subset of individuals with motor-complete SCI who respond to ambulation with moderate-to-large increases in heart rate.

Level 4 evidence (Ditor et al. 2005b) indicates that BWSTT can improve arterial compliance in individuals with motor-complete SCI.

There is level 2 evidence (de Carvalho et al. 2006) that neuromuscular electrical stimulation gait training can increase metabolic and cardiorespiratory responses in persons with complete tetraplegia.

Upper Extremity Training

There is level 1 evidence (Davis et al. 1987) that moderate intensity aerobic arm training (performed 20–60 min/day, three days/week for at least 6-8 weeks) is effective in improving the aerobic capacity and exercise tolerance of persons with SCI.

There is level 1 evidence (De Groot et al. 2003) that vigorous intensity (70–80% heart rate reserve) exercise leads to greater improvements in aerobic capacity than moderate intensity (50-60% heart rate reserve) exercise.

The relative importance of changes in cardiac function and the ability to extract oxygen at the periphery in persons with SCI after aerobic training remains to be determined.

There is level 2 evidence that hand cycling exercise increases the power output, oxygen consumption, and muscle strength in paraplegic, but not tetraplegic subjects during active rehabilitation. Conversely, there is level 4 evidence that hand cycling increases power output and oxygen consumption in subjects with tetraplegia.

Functional electrical stimulation (FES)– Lower Limb Cycle Ergometry and Hybrid (Upper and Lower Limb) and Other Electrically-Assisted Training Programs

There is level 4 evidence from pre-post studies that FES training performed for a minimum of three days per week for two months can be effective for improving musculoskeletal fitness, the oxidative potential of muscle, exercise tolerance, and cardiovascular fitness.

There is level 3 evidence (Jae et al 2008) that upper body exercise training can improve arterial structure and function in those with SCI.

There is level 4 evidence that FES training is effective in improving exercise cardiac function in persons with SCI.

There is level 5 evidence that arm-cranking exercise assisted by FES increases peak power output, and may increase oxygen uptake.

Based on the changes observed in VO2max and findings from able-bodied individuals a consensus (level 5, Expert Opinion) was derived stating that aerobic training is effective in improving the ability to extract oxygen at the periphery in persons with SCI.

Glucose Homeostasis

There is level 1 (De Groot et al. 2003) and level 4 (Chilibeck et al. 1999; Mohr et al. 2001; Jeon et al. 2002) evidence that both aerobic and FES training (approximately 20–30 min/day, three days/week for eight weeks or more) are effective in improving glucose homeostasis in persons with SCI.

There is level 4 evidence that the changes in glucose homeostasis after aerobic or FES training are clinically significant for the prevention and/or treatment of type 2 diabetes.

Lipid Lipoprotein Profiles

There is level 1 evidence (De Groot et al. 2003) to suggest that aerobic exercise training programs (performed at a moderate to vigorous intensity 20-30 min/day, 3 days per week for 8 weeks) are effective in improving the lipid lipoprotein profiles of persons with SCI.

Preliminary evidence (level 4: Solomonow et al. 1997) also indicates that FES training (3 hours/week, for 14 weeks) may improve lipid lipoprotein profiles in SCI.