Here is a dose of fitness news from FitBits, the news service of Exercise Etc. Take home information: (1) running is not as bad for hips as once thought; (2) eating carbs makes us crave more carbs later; (3) quick intense workouts are gaining in popularity; (4) exercise can modify our DNA in good ways.
August 15, 2013
Exercise ETC's Review of exercise-related researchCompiled by Laura Abbott, MS, LMT
Does Running or Walking Increase Your Risk of Needing a Hip Replacement?
Osteoarthritis (OA) is the leading cause of disability in the older adult population affecting between 7-25% of those 55 years and older. It’s also projected to become the fourth most common medical condition in women. While running and high impact activities have often been associated with increased risk of knee trauma and injuries, they do have benefits that may also reduce your risk.
Running reduces body weight (high body weight increases your risk of developing OA), and it may promote cartilage thickening. Researchers in Berkeley California investigated the role of running, walking, and other activities to see if one more so than another decreased the risk of developing OA in the hip and the need for a hip replacement.
Over 70,000 runners and over 14,000 walkers were tracked. Oddly, running was found to significantly reduce OA and hip replacement. The thinking was the reduction of body weight helped take stress off the joint. In addition to promoting weight loss directly, running also reduced the “middle-age weight gain” to only half as much as low mileage runners or walkers.
So, maybe running is not as bad on the joints as once thought. For those who do have issues, make sure your shoes are not worn out and consider running on a soft surface. If running just is not in the cards for you, walking is still a good option and better than doing nothing at all.
Williams, Paul T., "Effects of Running and Walking on Osteoarthritis and Hip Replacement Risk." American College of Sports Medicine, Medicine and Science in Sports and Exercise, Vol. 45, No. 7, July 2013. Pp. 1292-1297.
Carbs and Food Cravings
We have heard it many times: How much you eat determines weight loss or weight gain, what you eat determines how you feel. Well, what you eat also may contribute to how much you eat which affects weight loss/weight gain. Oh, the vicious cycle.
The American Journal of Clinical Nutrition published a study by Dr. David Ludwig showing that not all calories are created equal based on the effects on brain metabolism. Indeed, some nutrients seem to increase cravings for sugary, high carbohydrate foods. Not everyone will develop these cravings, but controlling them could be a first step in helping those who are battling their weight.
What is that first step? Limit refined carbohydrates and high glycemic foods such as bagels, white rice, juice and soda. Not only did these foods raise blood sugar, but they also elicited "pronounced responses" (cravings) in the areas of the brain related to rewards located in the pleasure center (hypothalamus). When subjects ingested a high-glycemic milkshake, blood sugar not only dropped into the hypoglycemic range, but scans showed more activation in the area of the brain associated with reward and addictive behaviors.
So, while we fitness professionals are always pushing "more exercise, more exercise," maybe we need to take a closer look at nutrition.
Ludwig, Davis S., "Effects of Dietary Glycemic Index on Brain Regions Related to Reward and Craving in Men." The American Journal of Clinical Nutrition. June 2013.
The Minimalist Workout
The appeal that you can get fit within a minimal amount of time has taken center stage even at the American College of Sports Medicine conference in Indianapolis last May. But is fit the same as healthy? And do these short workouts help with risk factors such as high blood pressure and cholesterol?
Many of the studies presented at the conference focused on short bursts of strenuous exercise can help with fitness... and maybe health. Some of the guidelines for exercise are just too daunting for some individuals. For example, in 2008 the Department of Health and Human Services came out with the guideline of 150 minutes of exercise. That is five 30-minute sessions per week. Sometimes, we fitness professionals are lucky to get a client to exercise two times per week for 20 minutes, if that. In fact, 80% of Americans do not meet those guidelines.
So, are the improvements we are seeing in these short bursts of exercise because of the intensity, or is it because people who normally would not do anything are trying these workouts? And do they help with risk factor reduction? We just don’t know yet. But at least we are getting some sedentary people moving, and that is pretty darn good.
Reynolds, Gretchen, "The Rise of the Minimalist Workout.” New York Times, June 2013.
Can We Modify our Fat-Cell DNA with Exercise?
A study done at the University of Sweden suggests that we can! Cells in the body - including fat cells - contain DNA, which is where our genetic information is stored. A small group of 23 sedentary men were followed for 6 months, who were asked to exercise 3 times per week without changing their diet or normal daily activities. As expected, the men only exercised an average of 1.8 times per week. However, it was still enough for the researchers to see changes in the DNA.
The methyl groups (molecules that are within the genes) help determine which genes are activated or deactivated. They found that these activations/deactivations were changed in the fat cells when these men exercised. Researchers also found positive changes in genes traditionally linked to Type II diabetes.
This could explain why exercise is so beneficial to certain risk factors, and that yes, we can make positive changes to our health through exercise.
Marie Ellis. "Exercise Can Have An Effect At DNA Level Against Fat Cells." Medical News Today. MediLexicon, Intl., 8 Jul. 2013. Web. 10 Jul. 2013.