Anabolic steroids are generally for gaining muscle, other things exist for weight loss and such. True SARMS are also work best for muscle gains. If your just looking for energy and getting your metabolism into high gear you could use Cardarine (not really a SARM, but commonly mistook as one) and this would probably be the route with the least sides according to current research. Other alternatives that are better are Ephedra, Clenbuterol, and T3. Use either the Ephedra or Clenbuterol, but don't stack these 2 as you ramp up the idea will be to find a tolerable amount of the individual drug. I can stand 120 mg of Clen a day, but my wife gets a bad headache at 10 mg. Thus she will use the Ephedra, not as powerful, but it still can get the job done. The wife stacks T3, I don't as I am already stacking Testosterone in the form of TRT and currently blasting a round of Tren. For me I take Clen for 2 weeks on 2 weeks off, otherwise the metabolism stops benefitting from it, but you still get all the negatives like night sweats, insomnia and elevated blood pressure.
If you are worried about muscle wasting a small amount of Anavar a day can help you keep your lean muscle mass. With your current idea of work outs, no reason to go over 5 mg a day and probably 2.5 would be more than enough as well. If you start hitting the weights harder you can step up on the Anavar for some lean mass gains and go to 10 mg. At 10 mg with on off cycles of 4 weeks and 4 weeks you should not have to worry about side effects with Anavar.
Let me tell you with the night sweats from Clen and Tren I might as well sleep in a bathtub.