A question for those of you who are experienced weightlifters. For the past year and a half, I have been using a high rep, low set routine. Two sets of 15 reps. In the summer, I started also incorporating, perhaps once a week or every other week, high sets, low reps....5 sets of 5 reps, using heavier weights. Should I switch over to only low reps, high sets, i.e. 5x5 or should I mix the set-rep combinations up, even including a hybrid such as 3 sets of 10 reps? I read in Men's Health magazine that for bulk and endurance , one uses high reps, low sets i.e. 15 reps, 3 sets, and that for strength, one uses low reps, high sets, i.e. 5 reps, 5 sets, using heavier weights.