**4.4 Type (modality)**

For safety, training on resistance machines with incremental weight stacks rather than using free weights is recommended (ACR, 2002; Pollock et al., 2000). Machines are also easier and quicker to set up. On the other hand, free weights allow more variety in the exercises performed and are better able to simulate ADL's. As mentioned previously, an optimal PRT program will feature exercises that collectively involve all the major joints and muscle groups. Such whole-body programs, as well as being more effective in increasing overall strength and muscle hypertrophy, also produce significant improvements in aerobic capacity (VO2max) and endurance performance. For example, Vincent et al. (2000) noted that 6 months whole-body PRT increased peak VO2 by 22% and treadmill time to exhaustion by 26% in elderly (60-85 years) men and women. Similarly, 10-12 weeks of HI PRT has been shown to improve time to exhaustion while cycling (47%), running (12%) and walking (38%) (Ades et al., 1996; Hickson et al., 1980).

Exercises should be performed rhythmically, in a slow, controlled movement (≈2 secs to lift and ≈4 secs to lower the weight) and, to avoid a Valsalva's manoeuvre and the resultant rises in blood pressure (BP), breathing should be continuous. When proper technique is observed, systolic BP during weight lifting is considerably lower than it is during aerobic exercise of similar intensity, and CV stress is minimal (Pollock et al., 2000). Naturally, with RA patients attention to affected joints is essential and joint pain, instability, poor proprioception, or reduced ROM may necessitate modification or substitution of prescribed exercises (ACSM, 2010c).
