Actually studies showed steroids will build power and muscle without even exercising so adding them to bag work could be more effective than weight training without steroids. Plus some effects of steroids stay in your body forever so even after just a cycle you will have enhanced nuclei in muscles. Of course only cowards who need to compensate for something take steroids, so there is that.
Also steroids are illegal, and have long term health side effects. So maybe just lift and eat more protein.
or people desperate to keep a career that offers them the only opportunity of a better life (E.G. almost all olympic gold medalists, and other athletes, who test positive)
One crucial part of your training that is often overlooked is strengthening the back. Your back muscles are involved in every move you make and it's often the weakest link. Any kind of back bridging exercise should be done regularly, around twice a week is fine. This will significantly improve your core stability which will mean the force going from the legs to the upper body and vice versa will be much stronger. Obviously don't forget abdominals - leg raises are great for those. In fact I highly recommend including body weight exercises as they are more closely related to martial skills than isolated weight training exercises. They utilise more muscles and do so using more natural movements than many weight exercises, particularly weight machines do.