Rest day???

Yes, you should give your body a rest day. It helps repair your muscles and helps keep you from getting burned out. You can overtrain.

I workout 4 days a week and the other 3 I do "active rests" 1 hour walk, hike, job.. or you could do 20-30 of High intensity interval training... http://www.bodybuilding.com/fun/ultimate-8-week-hiit-for-fat-burning-program.html

This was exactly the question I was looking for. I too am wondering if the rest day is necessary, as I find I lose my motivation if I skip a day.

Right now, I'm doing JM 30 Day Shred, level 1, and also taking a 2.5 mile uphill/downhill walk. I also just discovered Butt Bible level 1, and was hoping to add that to my daily routine. Would those three things still be considered mild enough to do every day without a skip day?

A rest day is needed for your muscles to recover. It's actually when you're not exercising that your muscles and body react to the exercise you've been putting them through. However, it does also depend on the type of exercise you do. If you're doing high intensity interval training, rest days are definitely necessary. But the idea of rest days don't have to mean doing nothing that day, a light session of yoga or DVDs such as X Stretch from P90X can be used on a rest day. As it goes, 30 minutes a day of exercise is recommended, but this is the likes of walking, moving about, as opposed to throwing on an Insanity DVD or hitting it at the gym targeting specific muscle groups for an hour and a half. Muscle groups also need to rest and a break as well, so. If you're doing high intensity exercises everyday, take a rest day and do something like yoga, go for a walk, easy bike ride, etc. rest days don't mean giving it up completely for the day.

I am a believer in rest days.

My two cents: I don't think a rest day is necessarily needed but variety definitely is!

Intensity should vary throughout the week, and probably so should the type of exercise. I haven't had any problems doing strenuous intervals most days in a row but I tend to think it is probably safer to do them no more often than every other day. Long slow exercise -- say at 60% of your maximal heart rate -- burns a lot of calories but can still function as a "rest day" if the other days are much more intense. A day of resistance training, or using the elliptical if you normally climb the stepmill, or rowing if you normally run on the elliptical -- these are good options too.

I have found that doing the exact same thing day in and day out (yeah, I've been there) leads to burnout more than it does to any actual injury.

If you use the "caveman/cavewoman" as a model of what humans probably evolved to be, I doubt they slept in one day a week -- that would pretty much mean a fasting and dehydration day, wouldn't it? But I doubt they ran up the same rocky slope chasing antelopes every single day either. I'll bet they said to themselves every so often, "I don't feel like steak today; I think I'll just head down to the berry patch instead!"

I think rest days are as important as exercise days. I take at least one rest day every 7 day period. I feel refreshed and stronger after a rest day. It is also amazing if you take a longer rest (5 to 7 days) you may actually feel stronger and have better performance.

I have a very busy day at work on Fridays, so I don't go to the gym, but I do burn a lot of calories at work. And I still walk the dog and sometimes walk around the block at work, but I call it a rest day.