Before my transition to women’s health, I cut my teeth as a physical therapist in the world of sports medicine, working with recreational and professional athletes. Most of my patients found their way to me as a result of three things 1) overly aggressive exercise program progression 2) moving too quickly back into exercise after time off or 3) bad form. And the bonus category of the overweight, middle aged male who after sitting all day behind a desk, decided today was the day he would dunk.

These three issues are intertwined. Exercises that are too difficult for you at your current fitness level will lead to bad form. The result, injury, and way too much time spent with physical therapists. To keep you exercising, making steady progress, and injury free, a few words to the wise to help you make well-informed decisions about how you exercise.

1. Know the physiology.

Building strength and making changes to your physical appearance takes time. 6-8 weeks to be exact. In the first 2 weeks of a fitness regimen you will experience strength improvements. This is related to better communication between the brain and your muscles, so they fire better. With consistency, over the next 4-6 weeks the muscles will actually begin to tone. They are actually adding muscle cells and you will be able perceive some changes in your muscles appearance. That is approximately 2 months to create a solid foundation, but it is still just the beginning of fitness, more time will be needed to reach your goals. Take Out: Plan ahead. If you know you want to lose pounds or inches before your June wedding or you want to run the Memorial Day 10K, don’t start training on May Day. Too lofty a goal, with too little time to prep, will likely force you into aggressive exercise and injury.

2.Watch your form.

Most folks read about a great exercise routine in a magazine or on the web for perfect abs, or strong shoulders and just dive in. The appeal of the end result overcomes them and they do the exercises without thinking through the precision needed for the movements. Or while attending a class or following a DVD, attendees sacrifice form just to keep pace with the instructor. Bad form not only increases vulnerability to injury but reduces results. Take Out: Slow down. Start by performing the exercises slowly and carefully in front of a mirror to be sure of your form. In a fast moving class, sacrifice repeated reps that use momentum for fewer reps, with perfect form, that get good results from the muscles you are trying to work.

3. Know when to say when.

Your body will give you clues that the exercise you are doing has moved beyond a challenge for your current fitness level, and into injury land. Breathholding is common when the you are not strong enough to pull off the activity you have chosen. Take Out: Just breathe. If you cannot perform an exercise without holding your breath, it is too difficult for you.

Pain is another clue that the activity is beyond your current capacity. Muscle work should bring about fatigue perceived at the middle of a muscle, this could sometimes be described as an ache that is relieved when the activity ends. But pain at the insertion of a muscle or in the joint is your bodies way of letting you know that you are doing damage. Post-exercise muscle soreness should be easing significantly in no more than 24-36 hours after your workout, any pain that lingers lets you know that you went too far. Take Out: Listen up. Your body is talking. It will signal you with pain, don’t ignore it. No pain, no gain is a long outdated fitness philosophy.

4. Build a comprehensive program.

Often exercisers focus on what are known as “mirror muscles”. These are the muscles on the front of the body that you can see in the mirror, ignoring those that cannot be visualized. This will lead to muscular imbalances that create faulty postures, injuries and poor results. Take Out: Think 360º. Every muscle has an opposing muscle group, this is the yin and yang of a workout. The bicep is balanced by the triceps, the quads are balanced by the hamstrings, and the abs are balanced by the gluts and lats. In order to maximize results, achieve healthy posture, and muscle balance think about a 360º program that works opposing muscle groups. If you yin, you gotta yang.

5. Be realistic.

If you trained and pulled off a 10K last Fall but the cold weather put a kibosh on your running program over the winter, don’t expect to run a 10K the first day of Spring. Muscles begin to lose the training effect of a workout after 4-5 days. A 4-5 month hiatus will set you up for an injury if you try to dive back in where you left off. Also, don’t think that Yoga Fusion DVD you did instead of weekly mileage kept you in running shape either. Muscle training is very specific. Yoga preps you for more yoga, not running, basketball or Zumba. Take Out: Smarten up. Evaluate your current fitness and activity levels (be honest!), the length of time since your last workout, and lingering injuries. Set gradual intensity, frequency and duration goals.

These guidelines, while universally applicable to men and women, are particularly important if you have had a baby. Too many moms, desperate to lose the baby weight and flatten their bellies, work themselves out too hard, too fast and end up with injuries, lousy posture and get poor results from their programs. The bottom line: use your noggin. And NO dunking.