Are you making these common training mistakes?

As a personal trainer, I am responsible for making sure that my clients are performing all of their exercises correctly. Proper form is a must, which means that I must watch their every move very closely. That's why I stand close, to make sure that no weight ever falls to the floor. And that no body part ever falls victim to injury. That said, sometimes it can be very hard for me to hit the gym sans client because I tend to be a huge people watcher. Without a client to watch, I tend to observe the people around me—and I see so many people using improper form. I get the urge to correct them, but feel it's improper. They didn't ask for my help, and I don't want to be the know-it-all.

But, I have this blog. And if you're here reading it, odds are good that you're in the market for fitness advice. So I urge you to take stock of yourself the next time you hit the gym. Be certain you aren't making these common fitness mistakes:

1) You've been doing the same routine forever. Switch it up! You and your muscles are probably bored, which is why you might not be seeing the results you really want. To increase muscle strength and size, or to decrease fat, you have to constantly challenge your body. And the same 'ol same ol' is not going to cut it.

2) You don't stretch or warm up. You know what it feels like to be sound asleep, only to have the covers pulled back and the light turned on, leaving your tired eyes squinting for solace. It sucks, doesn't it? Well, that's sort of how your muscles feel when you jump right into a workout. Ease them into your routine with some light stretching, then a warm up (treadmill, really light weights). And don't forget the cool-down either.

3) You lift weights that are too heavy. This is the mistake I see most frequently. Ignore the numbers on the side of the weight for a second and take a look at yourself while you're lifting it. If you can keep form through your desired number of reps, then you're fine. If you can't, then you are most certainly lifting a weight that is too heavy. Doing so puts you at risk for injury and minimizes the effect of the exercise on your muscles. On the flip side, you can also lift weights that are too light. Always, always challenge yourself. Read "Are you choosing the right weight?" for more information.

4) You blast through your workout at lighting speed. It's a good idea to move through your workout with minimal resting because it keeps your heart rate in its target zone. However, it's never a good idea to rush. Rushing through a program instills momentum where it shouldn't be, ups your risk of injury, and challenges your ability to hold proper form. In addition, if you can move rather quickly, you might not be using the right weight. Slow down, concentrate and really feel those muscles working. If you're crushed for time, choose exercises that combine more than one muscle group for maximum efficiency.

5) You focus on cardio, not strength. Or vice versa. Like peanut butter and jelly, cardio and strength training go together. Always. One isn't as effective without the other, so make sure you're getting a healthy balance of the two. And since I'm talking about cardio here, don't lean on the equipment! Or talk on your cell phone.

6). You don't drink enough water. Water is the fuel that keeps your body moving! In this world of sports drinks and Muscle Milk, I urge you to reconsider the vending machine in favor of the water fountain. Unless you're working out at a strenuous pace for longer than two hours, odds are good that water will work just as well as its liquid counterparts—and it'll save you some serious calories. Read "Peace, love, cupcakes...and water!" for more information.