I can jog for maybe a small or two before I'm not able to go any further, and recovery time is longer. I'm only 21, and slim. I walk a couple of miles the bulk days. I could perhaps walk all day without a problem, but anything more exerting, like jogging or climbing stairs, feels like it drains me more than it should. Can't climb a lot stairs without my heart beating hard. Can sometimes hear my heart beat quite easily. Squeak squeak squeak. That stops if I hold my breath - but the sound is faster than my breathing so I think it's a heart thing. Asked a doctor about the sound last year but they said not to worry. I cosidered I'd be able to jog further the more I try but after months I'm not getting any better at it. It just doesn't seem right when I observe people over 50 jogging far longer than I can.

Someone asked if I smoke. I don't.

Your unfit.

Different activities call for fitness in dissimilar muscles. It takes time to acquire both strength and endurance.



Your heart is also a muscle, and requires training.



If you only walk slow, it does nor benefit your heart much, nor your strength. Start walking faster part of the time, and just doing some stairs, but not ample to tire you.



Little by little you'll get sturdier and better endurance. Don't be concerned with your fitness tomorrow, it can't alteration much. Plan for your fitness a year from now. That can alteration dramatically with a planned, gradual fitness program.