1. Not exercising hard enough
One of the most common mistakes people make in the gym is overestimating how hard they are working. When it comes to weight lifting, people that routinely pick up and carry a 40 pound toddler are afraid to lift weights heaver than 10 pounds. You are stronger than you think. Try increasing your weights in 5-10 pound increments until you get to a weight that you can do safely, but still present your muscles with a challenge. The other error in weight training is resting too long in between sets. If your goal is to tone up/lose weight, you should be doing 10-15 reps and resting about 30-60 seconds between each set. If you are lifting for size and strength you should do 4-8 reps and rest anywhere from 2-4 minutes. The most efficient way to do cardio is to exercise within your target heart range. If your arms are sore after you get off the stair stepper or the treadmill, you are relying too much on your upper body. Hold for balance only, put the speed where it doesn’t require a death grip, and find out what you’ve been missing. The calories the machine says you burned will be more accurate and you can prevent elbow tendinitis.
2. Exercising too hard
The ugly twin of not exercising hard enough. If you always feel drained, your performance in the gym has been decreasing, you get sick more than you used to, your joints and muscles hurt, and/or you are getting frequent training injuries you may be overtraining. Rest is an important component to any exercise program. The more you sleep the more your muscles can grow and repair themselves. When you don't get enough sleep, your body's hormones will lead you to overeat. You should not work the same muscles on consecutive days, when you are doing a weight training program. If you bench press on Monday, don’t do it on Tuesday. Cardiovascular training can be done every day .
3. Improper form
You can work out at just the right intensity, but if you are doing it wrong you will not see results. Using momentum rather than muscle is a common mistake that prevents muscle growth. Ask a trainer if you think you may be doing something even a little wrong. Proper form can prevent injuries and increase your results.
4. Poor nutrition habits
The hardest part of being healthy for most people is the nutritiont. If are wondering why you work out so much and can’t see results, try keeping a food diary. Write down everything you eat and drink for a week. Be honest, exclude nothing (even the BLT’s when cooking– Bites, Licks ,Tastes), and it will be a real eye opener. The thought of having to write down that you ate an entire pizza by yourself can stop you in the act. After you complete the food diary, really look it over and analiyze your food choices.
5. Doing the same workout
We’ve all heard that the definition of insanity is doing the same thing over and over and expecting a different result. That applies to your exercise program. The body is a fine tuned machine that can adapt to just about any stresses you put it under, so you need to confuse the body with variety. Use different angles, different speeds, different exercises, etc... If you have been doing the exact same workout for years, you will benefit from trying something new. A good rule of thumb is to change your workout every 6-8 weeks.