It is okay to exercise with a cold. But make sure you do not have a fever, or anything that you can pass on to some one else.

Just makes sure that you are not too sick, and can breath well.

I disagree with makoto.

Things like these happens, you should wait the couple day to get better instead of further stressing your body, which will only prolong your time to recover.

Instead of your body focusing on one thing it has to deal with the cold and reparing muscles, therefore both aspects will not be as effective.

If you cold is bad, and it is more than just a head cold, it is okay to work out. However, if your symptoms are sever then it is better to take it easy.

Check this site out.

Http://www.Webmd.Com/content/article/62/71 697.Htm

The general rule is that if the discomfort is above your neck (a head cold), you can work out. But we�re talking moderate activity levels here. Intense activity, such as high-impact cardio or weight lifting, has been shown to weaken the immune system and have a negative impact on your body�s ability to fight a cold or infection. If you�re sick below the neck (respiratory infections) you�d be better off just staying in bed.

I actually got really sick once and it motivated me to start working out I felt better when I was running or being active than when I was just laying in bed being lazy. I got better after like a week and my will power is much stronger because I never made excuses not to work out. just remember to drink lots of water