Stretching exercises should play a leading role in any workout. (For Spectrum Health Beat)

The human body has about 600 muscles, most of them put to use in one way or another during exercise.

From your heart to your hip flexors, muscles are the most important body structure to think about in terms of strength and conditioning.

Here are some fun facts and tips to keep in mind when working to build, maintain or heal your muscles.

Building muscle

Did you know that exercise causes microscopic tears to muscles? The body’s way of healing muscles and adapting to an increased workload is to increase their bulk, which improves strength and muscle function, said Matt Axtman, DO, a physician with Spectrum Health Sports Medicine.

To optimize this healing response, it’s important for athletes to incorporate a rest day into their training schedule each week.

“A rest day will improve your performance and muscle structure and, most importantly, make you a better athlete,” Dr. Axtman said. “It also will help decrease overuse, muscle strains and tendinitis.”

Also, it’s vital to get sufficient amounts of protein because it helps build muscle mass, said Phillip Adler, PhD, a certified athletic trainer and manager of athletic training outreach for Spectrum Health Sports Medicine.

The National Academy of Medicine recommends adults get a minimum of 0.8 grams of protein per day for every kilogram of body weight, or just over 7 grams for every 20 pounds of body weight.

Cross-training

No matter if your go-to workout is playing one-on-one basketball, running a 10K, swimming laps or taking a brisk walk, your muscles need a change of pace now and again.

Cross-training, particularly when it targets weaker muscle groups, will improve endurance and stamina and also reduce your chance of injury, Dr. Axtman said.

“Doing one activity repeatedly without changing up a routine is much like continually driving a car in a circle,” he said. “It can wear the tire treads abnormally and cause alignment issues.”

If you’re a runner, target the upper-body muscle groups with a weekly swim, or vice versa. Yoga and Pilates will improve core strength and flexibility.

“The body grows accustomed to your daily routine,” Dr. Axtman said. “Cross-training results in muscle confusion, which is a good thing. It will make you a more proficient and well-rounded athlete and will help you take your workouts to the next level.”

Muscle soreness

As you build muscle, it only makes sense that some soreness will result, Dr. Adler said.

Stretching exercises, massages, foam rollers and massage sticks or balls can help combat muscle soreness, he said.

Swelling, a loss of range of motion, a loss of normal muscle function, or significantly more soreness on one side of your body could be an indicator of a muscle strain or other injury—and a sign that you should dial things back and seek an expert opinion.

While muscle soreness is a natural and expected part of improving strength, there are things you can do in advance to ease your level of soreness.

Two of the most important steps are proper hydration and adequate stretching—before and after your workout.

“Your muscles also need a warm up and cool down,” Dr. Adler said. “If you go straight from zero to 60, you put stress on your major muscle groups, which will result in additional soreness.”

Dr. Adler also advised against the urge to pop a couple of ibuprofen tablets or other anti-inflammatory medication to alleviate pain from muscle soreness.

“Inflammatory response is the body reacting to injury,” he said. “If we delay or diminish this, we risk prolonging the injury or having an inadequate natural response.”

So instead of Advil or Motrin, try Tylenol or another acetaminophen, he said.

There is also anecdotal evidence that a glass of chocolate milk will help your muscles recover after a strenuous workout, Dr. Adler said.

Any liquid will be quickly absorbed and digested after a workout, but chocolate milk in particular is a good idea because of the amount of carbs and protein it contains, as well as its essential amino acids.

Never give up

Maintaining your muscle mass becomes more difficult with age, but loss of muscle is not a foregone conclusion, Dr. Adler said.

In combination with strength training, a diet high in protein and low in fat will help you combat age-related muscle loss.

“Just keep at it,” he said.