The purpose of a "rest" day

I've read that your body's muscles needs to recover so youshould take a "Rest" day. Well I do cardio everyday from 30-70 minutes. I only do weights twice a week so this is spaced out...

but is a rest day realllly necessary? It seems I've read lots of conflicting information. Some day you should take one or two and others say you don't really need it as long as your type of exersizing varies.

i dont think your body needs to rest if you are only doing cardio.

i do cardio everyday too...for about 90 minutes. i love it and i need to do it to release stress. im not hurting my muscles because im not doing any strength related exercises..im just USING my muscles ie.being active. its just like someone who has a physically demanding job, they do it everyday and their bodies are fine. i sit on my butt all day so i feel like the hour i put my bod thru some hell..its A ok!

i take rest days, sometimes up to 3 a week.  i work out hard on the running machine, Eliptical, weights/abs and swimming. times vary for exercise, About a hour running, 20 weights and (up to) 3 hours swimming. So i take rest days or i get exhausted, Maybe thats because im hypothyriod - and i get tired easy but i find after a rest day or two my weight goes down and i feel so much better. I have a physicaly active job, i never sit down (apart from 30 mins lunch).

I feel i NEED rest days, as with everything though. Its whatever works for YOU.

I take 2 rest days a week.  The day before those rest days, I put in killer workouts.  Then after the rest, its amazing to see how my endurance has built and how much less fatigued I am while exercising.  But again, whatever works for you.

ok, cool sounds like I should just experiment a little.

jjlewis said it well - you come back stronger, build endurance, are better able to really hit your peaks on the day you come back from a recovery day. i worked with a personal trainer, and if i wasn't getting enough recovery, i was simply incapable of reaching the premium heart rate zones for training, even if i felt strong. recovery is important if you are exercising to build strength & endurance. if a person is just spinning to burn calories, at low intensity and not trying to max out their potential, then they might get enough recovery overnight.

I rest the day after my hardest workouts, usually 2 or 3 days a week.

On the one hand, each muscle group should, ideally, get 48 hours recovery time after a workout.

On the other hand, if you exercise lightly, vary your routines, and don't actually stress the muscles, that may seem like it is not necessary. Especially while you are still pretty young.

BUT--the heart is a muscle and some of our other muscles are getting a workout even when we vary our routines (because we use them just in remaining upright, for example). You won't feel an overtraining injury until it is too late (because it comes from regular pounding/use, not from falling or turning your ankle or another sudden event).

So, one day of complete rest each week is probably worth the "sacrifice." The muscles that are always working will be so much better off with it.

Good luck, whatever you decide.