Less is known about the effects of resistance training on cardiovascular fitness. However, the incorporation of resistance training into the treatment of SCI appears to be essential. In fact, muscle weakness and dysfunction are key determinants of pain and functional status in persons with SCI. Previous studies have revealed improvements in maximum aerobic power (Cooney & Walker 1986; Jacobs et al. 2001), exercise tolerance (Jacobs et al. 2001), and musculoskeletal fitness (Jacobs et al. 2001) after resistance training (e.g. circuit training).
As reviewed systematically by Phillips et al. (2011) two papers have evaluated the effects of upper body (arm) exercise on arterial function in SCI (Jae et al. 2008; Tordi et al. 2009). Jae et al. (2008) revealed that there were no significant differences in intima-media thickness, compliance, and beta stiffness index (a measure of arterial elasticity) of the common carotid artery between 28 competitive SCI athletes and 24 age-matched recreationally active able-bodied controls. Tordi and colleagues (2009) revealed (in a case study) that there was an improvement in aortic pulse wave velocity (central aortic stiffness) following six weeks of upper body training (30 min/session, 3 sessions/wk).
There is level 1b (Ordonez et al. 2013) and Level 2 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 1b evidence (de Groot et al. 2003) that vigorous intensity (70%–80% HR reserve) exercise leads to greater improvements in aerobic capacity than moderate intensity (50-60% HR reserve) exercise. It should be noted that many individuals with SCI cannot tolerate vigorous intensity initially, to which they must adapt often using a submaximal or interval type approach.
There is level 2 evidence (Milia et al. 2014) that arm cranking against a workload corresponding to 60% of WMax (performed 3-5 hours/day for one year) increases WMax and VO2 max.
There is level 2 evidence (Hjeltnes and Wallberg-Henriksson 1998) that hand cycling exercise increases the power output, oxygen consumption, and muscle strength in individuals with paraplegia, but not tetraplegia during active rehabilitation. Conversely, there is level 4 evidence (Valent et al. 2008) that hand cycling increases power output and oxygen consumption in individuals with tetraplegia. Further research is clearly warranted. There is also level 4 evidence (Nooijien et al. 2015) that hand cycling interval training program increases peak power output and peak VO2 in individuals with paraplegia and tetraplegia.
There is level 3 evidence (Jae et al. 2008) that upper body strength exercise training can improve arterial structure and function in those with SCI.
There is level 5 evidence (Hubli et al. 2014) that aortic pulse wave velocity is significantly lower in athletes (hand cyclists) compared to sedentary individuals with SCI.