Gained weight, cut my high intensity interval training back to every other day. will i be able to recover from amenorrhea soon? i'm healthy weight.

Yes: Your period should come back when you are no longer doing the high-intensity training. Your body interprets this as stress--like you are running for your life and it thinks, "Don't want to get pregnant or have a period while I'm running for my life!" And it shuts down your ovulation and periods. When it no longer feels this way, things should go back to normal. Best wishes!