Spanish researchers have gone to great lengths to correlate the blood levels of a variety of nutrients to the physical fitness of teens, while controlling for many variables to help assure the validity of their findings. Their results show that lacking key nutrients can compromise physical fitness.
Cardio fitness in teenage boys suffers if they are low in iron, vitamin A, or Vitamin C. Their strength is reduced if they are lacking iron, vitamin A, beta carotene or vitamin D. In teenage women, for both cardio and strength fitness, the key lacking nutrients were found to be beta carotene and vitamin D.
Since boys rely on a higher percentage of muscle for fitness, it is not surprising to see iron at the top of the list. Myoglobin is an important iron and oxygen binding protein found in muscle. When iron is adequate then oxygen can be stored in the myoglobin and released during exercise to sustain performance. Low iron invariably results in easy fatigue and as this study shows; poor fitness in teen boys.
Both groups need antioxidants in order to perform. Exercise increases the amount of free radicals due to the increased production of cellular energy. If antioxidants are lacking then free radicals become excessive, triggering fatigue and inflammation. Vitamin D determines how much inflammation can occur before it becomes excessive.
Teens have tremendous metabolic demands to grow their bodies. Athletic demands also compete for valuable nutrition. Better fitness and optimal growth can both be supported with a wide variety of good basic nutrients.


More...