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HPRC Fitness Arena: Physical Fitness
The scientific jury is still out on whether stretching prior to vigorous activity really helps prevent training-related injuries, but the scales tip in favor of doing some as part of your warm-up, just in case. HPRC has just added an in-depth review of the research literature and now offers information to help you decide the best way for you to incorporate stretching into your own fitness program. Check our our new Question from the Field, “Stretching during warm-up,” which also offers a link to even more detailed information.
There’s a phenomenon runners sometimes experience that’s commonly called “runners’ trots” – otherwise known as diarrhea – that has risk factors and that can possibly be avoided. Although the “trots” usually don’t last long and are generally nothing to worry about, they certainly can be a major annoyance, causing lost time in training or competition and even embarrassment if there is literally “nowhere to go.”
The most common risk factors cited are for those who are young, female, susceptible to irritable bowel syndrome, or lactose intolerant, as well as those who have had a previous abdominal surgery. The things we do to our bodies that reportedly increase risk are high-intensity exercise, dehydration, vertical-impact sports (e.g., running vs. biking), poor conditioning, medication, and diet. Although these are stated in the medical literature as risk factors, a recent study published in the International Sportmed Journal examined the evidence behind each of these risks to see if they hold up under scrutiny – and there’s surprisingly little evidence to support many of the statements about risk factors for developing “runners’ trots.” Most of the evidence was limited and relied on either single studies or multiple studies with varying results but a tendency toward supporting the conclusion.
Here are the conclusions of this evidence-based study:
The only strongly supported evidence was for dehydration to increase the risk of diarrhea. Female gender, younger age, high-intensity training, vertical impact, and medication had limited support and could go either way. Finally irritable bowel, lactose intolerance, previous abdominal surgery, poor conditioning, and dietary factors had very weak support. Keep in mind that little or no evidence does not make something true or false; it just means we have insufficient scientific evidence for any assumption.
So, based on the studies, how can you avoid “runners’ trots?”
- The evidence certainly supports staying well hydrated so that the bowel gets an adequate blood supply.
Even though the evidence for doing some things is not strong, they make sense and are not harmful. These include:
- Avoid a large meal 3-6 hours prior to running.
- Avoid food or drinks that have non-absorbable sweeteners (such as sorbital or sucralose), caffeine, and/or a high fat content.
- Don’t ingest concentrated carbohydrates (high glycemic index) before running.
- Be aware that energy bars and gels may contribute to the “trots” for some people.
- Avoid taking anti-diarrheal medications such as loperamide (e.g., Imodium) or Lomotil, since they can affect the ability of the body to tolerate heat.
- Wear loose-fitting clothing to reduce irritation.
- If symptoms persist for more than a few days, seek medical attention to be sure there is not an underlying cause.
Enjoy your run!
Warfighters have specific physical activity requirements, but their spouses, children, parents, and other loved ones also have physical fitness requirements for their own individual and family missions. HPRC's family section has a new area that summarizes recent guidelines for physical activity for U.S. adults, and children, and identifies military resources, interactive tools, and exercise workouts and videos. Check it out here!
Besides keeping you healthy and fit, exercise has another important benefit. According to a news release from Oregon State University, a study conducted on more than 2,600 men and women between ages 18 to 85 found that individuals who exercise for 150 minutes a week at a moderate to vigorous level experience a 65% improvement in sleep quality. In addition, active people experienced less daytime sleepiness than those who are inactive. These findings appeared to be across the board—subjects experienced better sleep regardless of age, weight, and other health habits. For many, regular physical activity can be an effective, non-pharmaceutical alternative to improving sleep and concentration levels during waking hours.
The study, which was published in the December 2011 issue of Mental Health and Physical Activity, adds more evidence to the amazing body of research that demonstrates the importance of exercise for overall health.
Running is a great exercise to help reduce your risk of heart disease and stroke. Running improves your cardiovascular system by strengthening your heart muscle and improving your circulation. As your heart muscle becomes stronger, your heart can pump more blood more easily. This helps deliver more oxygen to fuel your working muscles and remove byproducts such as carbon dioxide.
With the holiday season upon us, finding time for our usual workouts can sometimes be difficult. Two great physical fitness resources are the American College of Sports Medicine (ACSM) and the American Council on Exercise (ACE). Each has online workouts that you can try for free.
For a total body workout that you can do at home with free weights, try this total body workout from ACE that includes videos of the warm-up, the workout, and the cool-down. For a total body workout without additional equipment, try this at-home workout.
If you have less time, try this Basic Bodyweight Strength Training Program from ACSM.
Fit in these workouts in at home through the holiday season to keep you on track.
Brazilian Jiu-Jitsu—or BJJ—focuses on ground fighting techniques, also known as grappling. You can start your training at a level appropriate to your physical fitness, but ultimately you will find that your endurance increases as your opponent also learns the techniques designed to dominate. Although BJJ requires little to no physical strength—mainly technique and balance—you will find that your muscle tone and mass increase gradually without requiring weight training.
Swimming is an excellent way to reduce the risk of disease. It works your entire body and activates all the major muscle groups; contributes to muscle strength, flexibility, posture, and endurance; promotes weight loss and stress reduction; and improves cardiovascular conditioning by lowering your resting heart and respiratory rates and making blood flow to the heart and lungs more efficient. Swimming is also very low risk for injury because it places stress on your bones, joints, and connective tissues, thanks to the buoyancy of the water. Swimming 15 to 30 minutes each day can have a very positive effect on your overall health.
When training, an athlete should be specific about methods of training that meet the needs of the activity he or she is training for. To achieve an optimal performance level, a sprinter will train in a different way than, for example, an endurance athlete such as a marathon runner. Make sure that you “stress the physiological systems” right for your type of activity. In other words, if you are going to compete in a race, you need to run to become a better runner. Likewise, if you are going to compete in a cycling or swimming event, you must perform those exercises to become better. Wanna be a better tennis player? Play tennis! Although a well rounded program that includes strength training, aerobic conditioning, and flexibility exercises will improve your general fitness, to improve at a specific activity or sport you must perform that particular exercise.
The Los Angeles Times is reporting on how the Marine Corps has hired 27 certified athletic trainers—most with experience tending professional and college athletes—to oversee training for enlisted recruits and officer candidates at sites throughout the United States. According to the article, this is a new direction for the Corps: Not that long ago, the drill instructors might have dismissed recruits who complained of being injured and ordered them back into action.
To learn more about military recommendations for prevention of injuries related to physical training related, visit the HPRC’s Injury Management page and click on the link to read Recommendations for Prevention of Physical Training (PT)-Related Injuries.