i know pros work out in mountains where its probably colder and harder to breathe but can increase your stamina, where i am its pretty cold and makes it hard to breathe when i run also..so can it be effective workin out in cold weather??

ive heard it is cause you have to like work harder to get hot.. thats why you lose more weight working out in the cold or something.

I think the purpose of training in the mountains is the altitude, which means thinner air/less oxygen which leads to stronger lung capacity. I'm not sure if hot or cold is better though, hot means more sweating, so i guess thats better for trying to make weight.

Keep your joints and tendons warm or your greatly increasing your chance for injury,but the previous poster was correct it takes quite a few calories for your body to increase tempurture.

running in the cold expands your lungs i hear, so it is good to run in the cold to get your wind up. i personally hate working out in the cold, but the only i thing i do is roadwork in the cold, but i bundle up in MAD under armour and hats and scarfs.

i'm a "sun and hot as **** weather" kinda guy...

Running in the cold can get you sick. If it's below freezing, you can sustain damage to your lungs. I think it gets critical at around -5 to -7 degrees celsius.