I'm doing a strength training program, like stronglifts 5x5. I squat 3 times per week, my upper body exercises include bench, overhead press, weighted pullups, and barbell rows. I used to do track and field in high school, and I could just about anything without gaining fat. Now, I have to count my calories otherwise I start to gain weight. What are good workouts that can burn a lot of calories but not hinder my strength training?
-Some ideas: swimming, running, sprints, cycling. But I'm afraid doing too much will hurt my strength gains. Is it better to not exercise on rest days to actually rest?