After being truly fed up at my lack of weight loss despite exercising religiously, I decided to do a bit of reading up on the subject...& I found that overexercising can actually lead to weight gain:
TOO MUCH EXERCISE: Exercise is an essential part of maintaining long-term health and weight control. However, there is in fact such a thing as doing too much exercise, or exercising too intensely. Exercise is hormonally depleting, especially for women over 40.
If exercise is experienced as stressful, this can stress the adrenal glands. Adrenal glands make cortisol in response to stress. When there is too much cortisol release, the body goes into the "save" mode I mentioned earlier, and will retain weight, especially around the midsection. This is one of the most tricky subjects for me to discuss with my patients who are over 40, are healthy eaters, exercise intensely, and are frustrated by lack of weight loss or even weight gain despite all their efforts.
You have to exercise smarter, not harder. For example, exercise programs that include weight-lifting will build muscle mass, which in turn raises the overall metabolic rate. This makes a person burn more calories, even at rest! In other words, it's not just about burning calories by exercising harder. If your best efforts at weight loss are not working well, you may be over-exercising.
So how much exercise is too much??? Help! I am really stuck with this...
I'd say personally unless you are training under supervision or an establish program. Working out 6-7 days a week or twice daily (am/pm workouts) every day is too much (also 45-60mins is ideal workout time frame going way over can be too much working out too).
And by working out I mean an intense workout. Walking, easy pace jog, playing, swimming and leisure activities I believe can happen every day (and for longer periods of time). But moderate/hard/intense workout videos, weights, running and activities that really push you and your body should be only 3-5 days a week. Even with weights 3 days if you do full body routines and 4-5 only if you do splits. Rest or easy days or even weeks are needed if you workout moderate/hard.
Hmm ok in that case I definitely am working out too much. So do you suggest 3 days of Weight Training, and then the other 4 days cardio? It seems that I've been doing it wrong all this time :-(
I'd say you still need 1-2 rest/easy days.
So should I be doing WT and cardio on the same day then?
I believe it is debatable, some people like to have weight and cardio days separate but it can be done and is done by people. People tend to do weights first and cardio second. I am sure if you look it up there are may opinions and research  ;on weights and cardio on the same day or weights first or second? articles :)
I used to do cardio every day (elliptical about 20-30 min) and then alternate days with arms/legs weights.
Ok...and did you see good weight loss results doing that?
I am 45, 5'5", CW 140 lbs. I've lost 87 lbs since Jan 2010. Now I have 4 kids and 2 part time jobs and frankly I don't have a ton of time to exercise so I do 4-5 days a week. 3 days of weight training, some of those have a little cardio at the end. I'm following New Rules of Lifting for Women. The other 1-2 days a week I do cardio DVD's at home. My workouts are 45 min to 1.5 hrs depending on what is scheduled for that day. I usually eat 1600-1800 cals when in weight loss mode and try to get enough sleep, LOL. I have to say this has worked well for me. No huge plateaus and I have lost pretty much as expected for what I am doing. I also feel I can maintain fairly well and it's not a huge struggle.
Stress and lack of sleep can play a huge role in cortisol production and difficulty losing weight.
Thank you for your help :-) I have posted another topic on Cortisol as it is something I have been wondering about recently.
When I googled this topic for a friend I found this article.