So I exercise 5 times a week by lifting weights as well as 30 mins of cardio and some stretching every day. I still find myself running out of breath when walking uphill during my daily commute, for example, even though I'm in fairly good shape. My resting bpm is 57, for example, which is fairly low for a 205 lb 6 ft 1, 20 year old male. I'm a pretty big guy. Any suggestions for what the reason might be for running out of breath?
All I can wonder is how your diet is compared to how much exercise you do. You seem to be working out a lot and may not be supplying your body with what it needs. It is more important that you check why your heart rate is low, that in itself will make anyone more sluggish because your heart is not supplying your body with the necessary oxygen levels it needs.