Harvest plot of intervention effects on fitness and exercise capacity. Harvest plot of intervention effects on fitness and exercise capacity. Each box represents the findings of a single article, and contains the article number, which is underlined for studies with undefined wheelchair use, and the risk of bias rating (High, Unclear or Low). Article 2 measured aerobic (Aero) and anaerobic (Ana) fitness, and these are distinguished below by article number. Thomas D O'Brien et al. BMJ Open Sport Exerc Med 2016;2:e000109 ©2016 by BMJ Publishing Group Ltd