Sports, recreation and physical training are key to service members' health - physical, mental, and spiritual.

But those activities also often lead to the military's single biggest health problem: musculoskeletal Injuries.

Almost half of service members experience at least one injury a year, resulting in more than two million medical encounters across the military annually, according to a recent report.

More than half of those injuries are related to exercise or sports. Running is the number one cause of musculoskeletal injuries (MSKIs), which are blamed for more than half of all lost duty days across the military, according the report.

How can you avoid MSKIs? What does it mean to train "right"?

Taking a smart approach to training and other physical activities can greatly reduce the risk of injury and preserve your overall health and ability to deploy.

Service members should choose their activities carefully with a specific goal in mind. Stretching and warm-ups are an easy way to reduce risk. And, most importantly: Don't overdo it - pain and discomfort is your body's way of telling you to take it easy.

Whatever sport or exercise you choose, it's essential to do it right. Use good form and technique - getting sloppy or overly aggressive is asking for an injury.

"Motion is lotion," said Air Force Maj. Brandon Wielert, a clinical specialist in orthopedics and the physical therapy chief at David Grant USAF Medical Center, Travis Air Force Base, in California.

"Safe and appropriate movement is like the lotion to our movement system, vital for its sustainability," he said. "If a member is prompt to 'get the job done' at a high volume and intensity and has underlying movement dysfunction, it's a matter of time before they 'break'."

Same thing when service members "ramp up" for a PT test or train recreationally without enough preparation - it's only a matter of time before they break.

"Training 'right' involves a concept we call specificity of training," he said. This means "training in a way that most easily translates for the activity you are preparing for, such as attempting to improve one's 1.5-mile running time for the Air Force Physical Fitness Test."

In that case, many folks attempt to run multiple 5K races in preparation, but "this type of endurance does not best translate to a faster 1.5 mile race and increases the likelihood of overuse injuries," he said. Similarly, different types of jobs have different physical requirements, so they require a different approach to ensuring safe and specific training.

Training "right" also depends on your personal goals, said Navy Lt. Sarah Alferos, a physical therapist with the Physical Therapy/Sports Medicine and Rehabilitation Team at Navy Medicine Readiness and Training Command Pearl Harbor, in Hawaii.

"Whether it's addressing weight loss, muscle hypertrophy, increasing weights with lifting, vertical jump height, flexibility, etc., once you've identified your goals, specific exercise through proper exercise prescription and progressions will safely bring you towards them with minimal injury," she said.

The American College of Sports Medicine and Centers for Disease Control and Prevention recommend performing five days of 30 minutes of moderate-intensity aerobic activity, or three days of 20 minutes of high-intensity aerobic activity, plus working on muscular endurance and strength for a minimum of two days per week.

"Being in the military, it is important that we find a program that challenges a mix of our endurance, power, and agility so that we can perform our jobs without injuries," Alferos said.

"The best way to engage is finding workouts that fit our interests, whether it's group classes, competitive racing or lifting, working out with a partner, or following a workout program."

In addition to training with the correct exercises and technique, frequency, intensity, volume, and duration, all exercise should be followed by a proper rest and recovery period, said Army Lt. Col. Angela Diebal-Lee, chief of physical therapy at

Blanchfield Army Community Hospital at Fort Campbell, Kentucky.

"In a 24-hour period, it is paramount to ensure the athlete is also getting proper sleep and nutrition to support recovery and fueling needs to reduce injury and optimize physical and mental performance," she said. "Training is multifaceted and should be viewed as a holistic process defined by what you do before, during, and after the training session."

And "what is right for one person is not necessarily right for another," she added. "Ultimately, if you are training 'right' then you will be seeing objective progress towards your performance goals."

Overdoing it

Overtraining occurs when exercising at too high intensity or volume, said Wielert. "This is most easily identified with pain and/or an injury."

Performance can actually decline if you train more aggressively than your body can recover from, Alferos said.

A key warning sign is "slight pain or discomfort in an activity which did not elicit pain previously," said Wielert. "This is a 'yellow flag' that you should recognize and listen to with action: either stopping or slowing down."