I agree with these last few posts, kegeling should definitely help when it comes to conditioning the muscle required for a strong erection, which in turn should help performance length or number of full sex repetitions.
Also, I don’t see any reason why you would have to sacrifice other gym time. You can have the gym and sex, as long as you can devote enough energy to both!
Link to my PE Stats.
Goal: 9 X 6.5