5 Fitness Mistakes

Mistake #1: You Don't Use a Training Log

Training logs aren't just for muscleheads. Researchers found that 70 percent of exercisers who set goals stuck with their programs for the entire year. By contrast, three-quarters of those who didn't set goals dropped out. Keep it simple: Just write down the number of sets and repetitions and the amounts of weight you use, and the duration and distance of each cardio session, and your total exercise time. What’s more, this strategy works for eating habits, too.

Mistake #2: You Use Weights That Are Too Light

Ladies, I’m especially talking to you on this one. Your goal is to challenge your muscles, not just go through the motions. For instance, if you can lift a weight 15 times, it’s not going to do your muscles much good to lift it for only 8 repetitions. A good way to gauge if a weight is appropriate: Note the point at which you “start to struggle.” Let’s say you’re doing 10 repetitions. If all 10 seem easy, then the weight you’re using is too light. However, if you start to struggle on your tenth repetition, you’ve chosen the correct poundage.

Mistake #3: You Use Weights That Are Too Heavy

Gentlemen, this is typically a manly mistake. It's a product of a male’s natural inclination to be better than the other guy. But the only way heavy weights benefit your end goal is if you lift them with proper technique. Simply choose the heaviest weight that allows you to complete all of the prescribed repetitions, which you can do by employing the start-to-struggle technique in Mistake #2. To keep you honest, here are three signs you’re using too much weight: You can't perform an exercise through its full range of motion; You can't do your entire set without the help of a spotter; Your lower back arches like a sapling in a windstorm on bench presses and arm curls. If you have to change your body posture as you perform the exercise.

Mistake #4: You Do the Same Old Exercises

All exercises have an expiration date. That’s the point at which when they start to lose their effectiveness. A general guideline: If an exercise uses more than one joint (for example, the bench press uses the shoulders and elbows; the squat uses the hips and knees), you can do it for 8 weeks before you should switch to another exercise for the same muscles. If it involves a single joint (biceps curl, triceps pushdown, lateral raise), find a substitute after just 4 weeks. Your alternative can be as simple as changing the type of grip you use, switching from a barbell to dumbbells, or lying on a Stability ball instead of a bench.

Mistake #5: You Only Warm Up on a Treadmill

For most people, warming up means running on a treadmill or pedaling an exercise bike. And while a 10-minute aerobic workout is fine for warming your lower body muscles, when researchers at the United States Military Academy examined different methods of preparing for exercise, they found that first performing calisthenics—also known as dynamic stretching—helped people sprint faster, jump higher, and throw harder. The likely explanation: A dynamic warmup enhances nervous-system activity, which allows you to active more muscle fibers. So before you hit the weights, do 30 seconds each of jumping jacks, arm circles, pushups, lunges, and body-weight squats. You’ll instantly improve your workout—and as a result, your body.