Correct but you could have given him an analogy to help him understand.
A non-placebo analogy of "Just going through the motions" would be stretching and warmup before serious exercise, which provides a medically proven advantage to overall systemic performance, lower likelihood of injury, faster overall gains, etc.
Now a placebo of "Just going through the motions" would be skipping the exercise and watching an exercise DVD or perhaps watching a professional sports game on TV.
A non-placebo analogy of "Just going through the motions" would be stretching and warmup before serious exercise, which provides a medically proven advantage to overall systemic performance, lower likelihood of injury, faster overall gains, etc.
Now a placebo of "Just going through the motions" would be skipping the exercise and watching an exercise DVD or perhaps watching a professional sports game on TV.