BANKS!!!!

I'm sure banks will come on and give us a more indepth metabolism class but here it is.

Your metabolism establishes the rate at which we burn calories and effects how quickly or slowly we lose or gain weight.

A surprising fact: the more weight you carry the faster your metabolism is likely running. Extra weight causes your body to work harder just to substain rest. If you are carrying extra weight you need to increase your exercise and eat a healthier low calorie diet in order to lose weight, initially the weight loss will be quick and will slow down the closer you get to your healthy weight.

Men have more efficient metabolisms than women. Your metabolism slows with age by about 5% per decade after age 40. and your proportion of lean body mass to fat will effect your metabolism (the more muscle the more efficient your metabolism)

Ok, so the short answer is yes, you can "speed up" your metabolism but you must increase your exercise and eat a low fat healthy diet in order for it to happen. So in other words, get up and get moving and if you are already doing that move a little more!

I wanna know toooooooo

Sorry, this went longer then I really thought it would. My bad.

HOW did I miss this thread?

Oh well, some great people already pretty much answered the first question. Metabolism is based on 3 things, fitness level, genetics, and body chemistry. cp and Nich0le pretty much got it right. To increase your metabolism (assuming you have no thyroid problems or chemical imbalances) you need to gain muscle mass (either density or size), reduce fat content (because fat doesn't require energy to be fat, only to be burned where as muscle requires energy just for everyday use), and increase the heart muscle. You increase these by physical activity.
BUT by eating a well balanced diet that follows RDA, you will speed that process up. That means no weird diets that eliminate one type of nutriant, no "low carb" dieting (carbs are fuel, they normalize how the body works), and eating on a schedule that gives your body a slow, constant stream of energy throughout the day. Oh and letting your body sleep for a good 7 to 8 hours a night is a HUGE help.

As for Firegirlred's quesiton about muscle soreness, here is my answer. (Please remember that I'm not a certified trainer ...... YET but I have been a serious athlete for over 20 years and know a thing or 2 about recovery times).

There are 2 types of muscle soreness (which you already know), the first is the immediate soreness that comes when failure is approaching, this is caused by anaerobic work. When the muscle runs out of available oxygen to burn the ATP molecule, glycogen stores take over in the body, the by product of anaerobic activity is lactic acid (this is an over simplification but it works for our purposes). This lactic acid is the "burn" you feel as the muscle become saturated with it. It takes approximately 2 minutes for the muscle to replenish oxygen stores.
The other soreness comes after, it's a combination of the muscle stiffening back up, regenerating (microtears in the muscle and sheath are healing, this is a GOOD thing as the muscle becomes stronger and thicker as it adds tissue to fill in the tears). If you feel soreness a few hours after you work out (especially in weight training) you need to allow that muscle group time to heal. Usually, using a well balanced diet, and giving that group 24 to 48 hours of inactivity is plenty of time, but use your best judgement. Using muscles that haven't fully healed yet will result in dramatically reduced results. Fatigue onset is faster, and any muscle strengthening will be diminished.
So that all being said, give yourself heal time. Do muscle groups instead of full body training, that gives you time to recover one group (say shoulders, arms, and chest one day and legs and core another, then a day of cardio only as a third).

2 notes. a 7 day week is perfect for this type of routine, 6 days of exercise and 1 day of complete rest is a great workout routine when encorporating weight training, that gives you 2 days a week on each muscle group with 2 or 3 days rest between. Also, when training it's VITAL to stretch the muscles after working out, muscles will snap back after exercise like a rubber band, and retain that under extension as it heals if you don't stretch it out, good for body builders who want to show off muscle, but bad for anyone who wants any kind of range of motion or functionality in their muscles.

As to food, the basic plan is, if you're working out, increase your protein to about the 25% range, lower your carbs to about 50% (which leaves fats at about 25%, which is fine). also try to have carbs about 2 to 3 hours before (complex carbs please, something that sticks around for a few hours), and a moderate amount of protein after (1/2 hour to 1 hour after is good). Forget the protein suppliments, as they don't have all the essential amino acids you need, or at least, suppliment the suppliments with other things that activate and combine the protein correctly like skim milk, orange juice, broccoli...etc.

If you want to learn more about how protein is used in the body here is a good link. It's more complex then just "It builds muscle". http://en.wikipedia.org/wiki/Essential_amino_acid

Now that Songbyrd is back on here, I'm sure she can add to this, but I think it answers your question.