Why do you get tired when you run?

[jsmoke]

Take a 5k, probably short for most runners.

After about 2.5k I feel a hit coming on, my legs get a bit sore and breathing increases, I'm also sweating a lot.

Why is this, is it a lack of oxygen getting to the muscles, is it dehydration from sweating, or lactic acid built up, of maybe it's carbon dioxide build up, or what is the process that's tiring you and making you gasp for air.

I assume if your muscles got a constant supply of oxygen then you'd be able to run for 1000's of miles.

 

[jsmoke]

Build up of lactic acid switch over from aerobic to anaerobic respiration etc. Everyone gets it distance runners have stamina to keep going sprinters are almost entirely aerobic. Basically surplus oxygen gets used up so lactic acid builds up until you rest when the body has a chance to metabolise it then you get your energy back. Stamina builds up with training.

so basically the body doesn’t manage oxygen very well if you get tired easily. Hence people turn to PED’s.

 

[jsmoke]

Have you tried running further then 5k?

I always feel a bit rough at the beginning of a run, but normally will feel more comfortable a few k more. I will happily run 10k without prior training. When I did used to run regularly (10k, 3times a week) I always found the beginning few ks the worst.


I think the difficulty in the first couple of k, is kind like your body is being shocked, you're lungs, heart, legs etc are suddenly working much harder than they had been. It takes a while for the endorphins to kick in.

Just did 6km. The difference is night and day now. I was just really unfit and mentally weak. I credit a lot to doing squats, they really changed everything for me. Now running at 5.30min/km feels like jogging yet stepping up to the next level is going to take a whole lot of pain again, which I'll do.

I'd really done nothing for over 15 years and was still living in the past like 25 years ago thinking I'm still a runner but in a month I've come right back to some sort of base fitness Some very painful runs though. So much is mental, my bodies been screaming to stop yet I made it. I truly realised today the power of the mind today, once its expects a set of variables it doesn't want to step outside of that framework. Feels good to be getting back.