ISSA College of Exercise Science Weekly Wisdom

The human body contains small amounts of a calorie burning tissue called brown fat (brown adipose tissue, BAT) that converts food energy directly into heat. White fat does the opposite— it stores energy. BAT is an important heat generating tissue in hibernating animals. It promotes non-shivering thermogenesis, which generates heat and helps animals and humans adapt to the cold. Individual differences in BAT content and activity plays an important role in human obesity. BAT is turned on by the sympathetic nervous system, which is the body’s fight-or-flight system for coping with stress and emergencies. However, a recent study by Piryank Motiani from Turku University in Finland and colleagues found that exercise, an important activator of the sympathetic nervous system, was not a significant stimulus for brown fat activation in middle-aged men. Increasing brown fat activation helps people expend more calories and burn more fat. Cold exposure and key nutrients, such as L-arginine, L-citrulline, and L-glutamate can increase brown fat activity, which increases caloric expenditure and promotes fat burning.

Want to improve your fitness quickly, but don’t have a ton of time to spend in the gym? You may want to consider high intensity interval training. This intense but effective method involves repeated bouts of maximal exercise followed by rest. Athletes have practiced HIIT for more than 100 years, and active fitness enthusiasts are finding that it produces results quickly. Many studies have found that HIIT can result in impressive increases in maximal oxygen uptake, endurance, glycogen storage, and aerobic enzymes. What normally would take six months or more can be done with just a few weeks of training! A review of literature by Martin Gabala and John Hawley concluded that HIIT is especially effective for improving health and wellness. High intensity training enhances the capacity of cells in the mitochondria (powerhouses of the cells), which are critical for longevity in good health. This is a terrific training method for people who want to build fitness quickly without spending too much time working out. The method is intense but effective.

A review of literature by Arturo Figueroa from Florida State University and colleagues concluded that L-citrulline and watermelon reduces resting blood pressure, and chronic use may increase endurance. Citrulline is an important amino acid involved in the formation of urea. It is a popular component in athletic food supplements because it participates in key amino acid reactions and influences blood flow by increasing nitric oxide levels. Nitric oxide (NO) is an important chemical secreted by the inner lining of the blood vessels that controls blood flow throughout the body. NO is vital for muscle blood flow, sexual function, fuel and hormone delivery to muscles, tissue oxygenation, and general energy levels. Other studies found that citrulline increases brown fat activity, which increases caloric expenditure and promotes fat burning. Citrulline increased levels of hormone-sensitive lipase by 150 percent, which promoted fat mobilization and use. Citrulline is an underappreciated supplement that improves fat burning and muscle blood flow and protects the gut from injury during exercise.

Over two thirds of Americans are overweight or obese. While excess fat accumulates in the abdomen and around the hips, it can also build up in the liver, which is the body's most important center for metabolic regulation. Fat buildup in the liver cells, which impedes the function of the cell nuclei (cell gene centers), triggers liver cell inflammation, and eventually leads to scarring. This is an extremely serious condition that can result in a liver transplant or death. Contributing factors include unhealthy diets, elevated levels of VLDL (the principal triglyceride carrier), and insulin resistance. As with most poor health conditions, the solution is regular exercise, healthy diet, and preventing obesity. How people lose weight could be important. A study on rats led by Yuka Kurosaki from Wayo Women's University in Chiba, Japan found that following a high protein-fat diet led to fatty liver disease. This popular weight loss diet can have severe metabolic consequences that could eventually be life threatening.

As advocates for creating a stronger and healthier world we are ardent supporters of the tremendous benefits of physical fitness for everyone.  Physical fitness is widely recognized as a powerful marker of health-related outcomes, both in childhood and adulthood and an important determinant of current and future health status.  Adolescents’ physical fitness levels are an important indicator of their lifestyle and seem to have positive consequences in health-related quality of life.  Research on health-related quality of life (HRQoL) has increased in the last years. HRQoL can be defined as a multidimensional construct that relates to a person's self-perceived health and consists of ratings of well-being and functionality in important life areas, including physical well-being/functioning, emotional well-being, self-esteem, social functioning, and family relations.

Visit your local neighborhood gym or club and you will undoubtedly see people engaging in downhill running or walking, depth jumps, abdominal rollouts, etc. which are all exercises focused on the eccentric rather than the concentric contraction.   Eccentrics are the downward portion of the exercise, such as lowering yourself in a squat or lowering the bar to your chest in a bench press.   More focus in being paid to eccentric exercises for good reason. Studies have shown that your body can tolerate up to 1.75 times more weight eccentrically than it can concentrically. Skeletal muscle generates force by either shortening (concentrically) or lengthening (eccentrically). Eccentric exercise is characterized by a lower metabolic demand and requires less muscle activity than concentric exercise at the same level of exerted force.   

In response to a global decline in children’s and adolescent’s physical activity participation, parents are looking for ways to foster lifelong exercise habits for their children. However, is physical activity and team participation enough? 

A recent study suggests approximately 75% of Americans eat excess amounts of sugar.  From cupcakes to pies to ice cream, sugar is found in many foods. I, like many of you, enjoy sweets. (My Achilles' heel is cheesecake.

As the cold begins to give way to the warmth of spring, there is nothing I enjoy more than walking barefoot on the beach, in the park or my backyard.  The act of walking barefoot in nature is known as earthing.  Like myself, many people report amazing benefits, while critics point out the lack of solid scientific studies supporting this practice.  Earthing (also called grounding) can be a controversial topic. What say you?  Are you part of #teamgrounding or #teamnogrounding.

Supplementing melatonin might promote weight control— according to the results of a study on mice by Italian researchers. Lean and obese mice were given melatonin or a placebo in the drinking water for eight weeks. Melatonin reduced weight, fat storage area, and reverse fat tissue enlargement in the obese mice but not the lean mice. It worked by decreasing inflammation and normalizing adipokines, which are important fat signaling chemicals. A study on mice by Pengfei Xu and colleagues from Beijing Normal University in China found that melatonin altered the composition of microbes in the gut, which promoted fat loss. Melatonin supplements help promote sleep and weight control.