© Saxon. 2015
Published: 6 August 2015
Some steroid drugs are designed for clinical use to combat muscle-wasting diseases, but are also used by athletes to improve their performance by increasing muscle strength or endurance. This study investigated the effect of one steroid drug on the number of times a weight could be lifted by healthy male subjects as a measure of endurance. The ratio of number of lifts performed with a steroid-injected arm versus a sham-injected control arm increased with the drug dose; the authors therefore concluded that the drug improved endurance.
The control varies between treatments, and so the experimental to control ratio increases with drug level in the experimental arm largely, though not entirely, because the function of the control arm is worse. Regardless of whether this represents a real biological effect, the way the data were processed and displayed in the top graph was inappropriate — this example highlights the importance of examining raw and not just processed data.