[retrac]

They do work that way. Lots of studies show gains in muscle mass even with no excercise when people are on steroids. Consider average men who never excercise vs average women who never excercise. The men will have more muscle. That's what testosterone does, among other things.

That's part of why steroids were and sometimes still are used medically for people with cancer and other wasting diseases. It makes them eat more (they're usually strongly appetite inducing) but they also just help develop muscles even if sedentary.

(Of course it would be far more effective to also engage in high intensity resistance training.)

[3eb7988a1663]

One completely random study result[0] supporting that couch + testosterone leads to bigger muscles. Maybe it is some puritanical thing, but not sure why this myth persists. Exercise + juice results in even bigger gains, but it is possible to increase muscle mass without hard work.

  ...The men in the testosterone groups had significant increases in the cross-sectional areas of the triceps and the quadriceps (Table 4); the group assigned to testosterone without exercise had a significantly greater increase in the cross-sectional area of the quadriceps than the placebo-alone group

[0] https://www.nejm.org/doi/full/10.1056/NEJM199607043350101

[maccard]

Steroids are usually given to reduce inflammation and as immunosuppressants to stop the body from fighting back against whatever treatment is being given. The main method of weight gain with prednisone (the most common steroid) is water retention. Anabolic steroids are not commonly prescribed to cancer patients.

Cortico steroids usually result in muscle mass loss.