Does Masturbating Before You Work Out Affect Your Performance? affects other activities like lifting weights at the gym varies from
Basically, sex and masturbation aren't detrimental or helpful when it comes to moderate or intense exercise in any way. Your heart rate elevates for several hours after having an orgasm, and it can elevate even more if you work out post-sex or masturbation, but that's about it.
In the end, having sex or masturbating before a workout does a little to affect your workouts. All that matters is, you should be having fun in the gym. If you think