Nutrition
High-intensity exercise increases levels of chemicals such as hydrogen ions, inorganic phosphates and adenosine diphosphate, which slow down biochemical reactions and promote fatigue. Buffers such as bicarbonate and carnosine can help neutralize these chemicals and promote performance. Carnosine, which is made from beta-alanine, is an important antioxidant that protects cells from destruction and buffers acids that cause fatigue. Muscle carnosine levels are closely linked to maximum training capacity. Supplementation with carnosine or beta-alanine increases muscle carnosine levels, which increases the acid buffering capacity of the muscles. Muscle carnosine levels decrease with age, reducing the capacity for high-intensity exercise.
Jordan Glenn and colleagues from the University of Arkansas found that supplementation with beta-alanine for 28 days increased lower body muscle strength and exercise capacity compared to a placebo in female Masters athletes.
Beta-alanine is an effective supplement for intensely training, older female athletes.
(Journal Strength Conditioning Research, 30: 200 - 207, 2016)
Myelin is an insulating layer that surrounds many nerve fibers and increases the speed of neuronal conduction. The amount of myelin around nerve cells increases when you learn skills such as swinging a golf club, squatting, juggling or cycling. Skill training works in part by increasing the amount of myelin.
Omega-3 fatty acids can increase the myelin content of motor nerves and improve motor skills, according to a study led by Evan Lewis and conducted at the University of Toronto. The study showed that supplementation with omega-3 fatty acids for three weeks during high-intensity exercise and maximal squats increased muscle activation and reduced fatigue.
(Journal International Society Sports Nutrition, 12: 28, 2015)
Muscles get energy for contractions by breaking down adenosine triphosphate (ATP) - an important compound that provides cells with most of their energy. Creatine phosphate is an energy-rich chemical that restores the full energy levels of ATP after it has released some of its energy. Creatine phosphate does this by providing an energy-rich phosphate to regenerate ATP.
Creatine monohydrate supplements increase creatine phosphate levels in muscle by 20 percent. Most ATP comes from reactions involving oxygen, but these reactions are slower than the energy-rich reactions involving ATP and creatine phosphate.
Brazilian scientists have shown how creatine phosphate, which is synthesized from creatine monohydrate, could improve performance during high-intensity cycling sprints. Athletes who followed a creatine loading protocol (20 grams per day for 5 days) showed lower oxygen demand during the initial phase of a one kilometer timed sprint.
The body will preferentially use the energy that is available to it. He chose to use more creatine phosphate during the initial phase of the sprint because more of it was available.
(Medicine & Science in Sports & Exercise, 47: 2660 - 2668, 2015)
Recent studies on fat intake have confused even experienced nutritionists and biochemists. For more than 35 years, nutrition experts have strongly recommended avoiding saturated fats and dairy products and increasing consumption of carbohydrates and polyunsaturated fats.
In 2014, a landmark meta-analysis that analyzed the results of 44 studies (Chowdhury et al.) showed that saturated fat consumption had no effect on coronary artery disease compared to other fats. In addition, other studies have shown that the consumption of dairy products actually reduced the risk of coronary artery disease.
An editorial in the American Journal of Clinical Nutrition concluded that scientific studies do not support the concept that saturated fats and dairy products increase the risk of heart disease. Dietary health and wholesomeness should be based on total dietary intake, not individual components.
This issue is not dead yet. Peter Jones and colleagues showed that fat metabolism is influenced by the composition of fats. Monounsaturated fats, which are found in large quantities in the Mediterranean diet, could promote fat loss. Genetic variations could also influence the effects of dietary composition on fat metabolism.
(British Journal of Nutrition, published online on January 25, 2016)
The amino acid L-arginine increases endurance in athletes and improves metabolic health.
A study conducted with rats under the direction of Amin Alamshah of Imperial College London, England, found that L-arginine stimulated the release of digestive tract hormones (GLP-1 and PYY), which reduced food intake by suppressing the hunger center in the brain.
L-arginine is the universal ingredient of the supplement industry. The body uses arginine to produce nitric oxide (NO), stimulate growth hormone release, synthesize creatine, promote tissue healing and produce new proteins - all of which enhance exercise performance. Arginine is particularly effective for endurance athletes as it increases nitric oxide production, muscle blood flow and oxygen delivery to body tissues. Nitric oxide is a chemical secreted by the cells that line the inside of blood vessels and it increases blood flow and nutrient delivery to skeletal muscle. Arginine supplements may also help regulate blood pressure, enhance sexual performance and suppress an outbreak of herpes simpex.
We need further research to be able to say whether arginine is also an effective anti-obesity supplement.
(Diabetes, Obesity and Metabolism, published online February 11, 2016)
