Sometimes when we start a new workout routine, we expect too much. Fitness and nutrition can change your life, but they can't change it overnight.

In the battle to lose weight, get in better shape and achieve a higher level of health and fitness, there is no greater resource than knowledge. Knowing what to do, how to do it and when to do it can be the difference between success and failure.

Similarly, knowing what to expect (and what not to expect) can be the difference between a sense of accomplishment and the feeling of disappointment. Sometimes when we start a new workout routine, we expect too much. Fitness and nutrition can change your life, but they can’t change it overnight.

Here are nine brutal truths of fitness that, once accepted, can help you set realistic goals and reduce frustration.

1. The older you get, the harder it gets.

Losing weight at 40 is harder than it was at 30. Working out at 50 requires more thought, planning and recovery time than it did at 20.

As we age, we get weaker and less flexible. We have more aches and pains and our metabolism slows. All of those things mean we can’t expect to make the same progress now as we did when we were much younger, even if we work harder.

But that doesn’t mean we should quit. Those very things that we’re fighting against (weakness, weight gain, stiffness and pain) can be reduced with exercise and sound nutrition. We just have to be smarter about how we exercise: not lifting as heavy, being careful with repetitive motion, taking time to warm-up and stretch, and giving muscles and joints enough time to recover.

Getting older isn’t an excuse to quit; it’s an opportunity to use our hard-fought wisdom to workout smarter.

2. It’s harder to lose weight and gain muscle if you’re a woman.

You can put in more time at the gym, follow a more disciplined diet and spend less time on the couch than your husband, but he’s still going to lose weight and maintain muscle mass more easily than you. And his body is going to be more forgiving of the bottle of beer he just had than yours will be with the glass of wine you just had.

As a woman, your body is designed better to store fat. His is designed better to build lean muscle.

That doesn’t mean you can’t build muscle and lose fat; it just means it will take you longer. So, don’t compare your progress and you accomplishments to his, or to anyone else’s. Be the best you that you can be.

3. Injuries will happen.

If you strength train, you will eventually have a strained muscle. If you run, you will eventually have joint pain.

It’s a numbers game. Anybody who does anything active has the potential to suffer an injury from that activity. If you do the activity long enough, you increase your chances of getting injured.

That doesn’t mean we shouldn’t exercise. The benefits far outweigh the risks. But learn to listen to your body. Figure out what kind of training is best for it and which exercises are most like to cause it pain. Adjust your workouts accordingly.

4. It’s easier to get in shape than it is to lose weight.

After just a week of exercise, our bodies start to respond. We can improve our strength, endurance and flexibility almost overnight.

But losing weight? That’s a painfully slow process that requires unrelenting commitment and dedication over a long period of time.

5. It’s easier to lose weight than it is to keep weight off.

Why do so many people lose weight only to put it back on? Because they never accepted the fact that healthy, weight-controlled eating is a way of life, not something you do to lose weight, then stop doing once you’ve lost the weight.

The commitment is for life.

6. Weight goes on more quickly than it comes off.

Why is it that you can cut calories for weeks only to lose a few measly pounds, but then you put them back on (and more) the minute you have that burger and fries? Because our bodies were designed to store extra fat and they would rather keep it than let it go.

7. Genetics play a role.

Some people lose fat easily. Some people gain muscle easily. Hating those lucky few won’t make it any easier for you. Some people are better looking. Some are good listeners. For some, math comes easy. We all have to play the game with the cards we were dealt.

8. You can’t have your cake and eat it too.

Think you can make up for a poor diet by working out longer? Think again. Think you can have a toned body by eating right but not hitting the gym? Good luck. For spectacular results, a spectacular all-around commitment is required.

9. There is no magic pill.

Fad diets come and go. Nutrition companies will always promote the next, great potion for weight loss. Celebrity-endorsed gizmos will continue to rule the late-night infomercial circuit. None of them will ever replace hard work, disciplined eating and a healthy lifestyle.

Frank Shelton is a certified fitness trainer and owner of Frank Shelton Fitness. He can be reached at (302) 463-4000 or frank@franksheltonfitness.com.