I used to go with really heavy weights combined with cardio...cardio six days a week in the mornings, weights in the afternoon four or five days a week. I was 255 lbs, at 6'2', and could hit really hard but found my stamina sucked. Then I switched to cardio six days and weights only three days, and less weights with more reps. Went down to 205 lbs, and I felt a LOT stronger, still hit plenty hard enough and had a lot more stamina. So, I don't know, that's just how it worked for me, everyone is different I guess. I also found diet can really make a difference in how strong a person feels. I went on a veg diet for six months, but used a lot of protein powder, and felt kinda weak at times, not sure why. Was really ripped and could work out for hours, but just didn't feel as good somehow, so maybe there's other stuff in meats besides protein that help?