Written by justis berg
25 October 2010

Low Energy Intake Suppresses Protein Synthesis

Athletes need calories to supply energy for intense exercise. Energy intake is also important for turning on chemical pathways that promote protein synthesis, muscle growth, and strength. Stefan Pasiakos from the University of Connecticut at Storrs, and colleagues, found that reducing energy intake by 20 percent suppressed signaling pathways that control protein metabolism and decreased protein synthesis. This study showed the importance of maintaining adequate energy intake during heavy training. You cannot make gains in muscle size and strength if you don’t eat enough food. (Journal Nutrition, 140: 745-751, 2010)

Low Vitamin D Intake Decreases Muscle Mass and Strength

Vitamin D is produced naturally in the skin as part of a reaction involving sunlight, but is also consumed in the diet. Many people are vitamin D deficient because they shun vitamin D-fortified dairy products and don't get much outdoor activity. Vitamin D is critical for normal calcium metabolism and plays a vital role in maintaining bone and muscle health. A review of literature by Bruce Hamilton, and a study led by Vicente Gilsanz from the University of Southern California (USC) concluded that adequate vitamin D levels were important for promoting muscle mass and strength. The USC study showed that women with low intakes of vitamin D had increased levels of muscle fat. Dr. Hamilton concluded that vitamin D plays a critical role in muscle protein synthesis and suggested that vitamin D-deficient athletes might benefit from ultraviolet B radiation (i.e., tanning beds). Dermatologists would undoubtedly disagree, because of the link between tanning beds and skin cancer. (Scandinavian Journal Medicine Science in Sports, 20: 182-190, 2010)