Nutrition and the athlete – information for the weekend warrior to the endurance athlete:

The intensity of the exercise determines the way that the body makes energy for the muscles.  A high intensity, short duration activity such as lifting weights, or sprinting rely on anaerobic pathways for production of ATP, or energy.  This pathway uses glycolysis, or glucose to create ATP.

A moderate to low intensity, and long duration activities such as swimming, long distance running, and walking rely on both glucose and free fatty acids.  A good source of glucose for these types of athletes is a moderate amount of complex carbohydrates with low fat intake.  Vitamin B1 helps with the breakdown of carbohydrates in the body.

Following 30 minutes of medium intensity activity, fat is used almost exclusively for 4-6 hours post exercise.  Protein sources are only used if carbs are unavailable, and fatty acids cannot supply enough energy.  Therefore it is important for athletes to consume essential fatty acids such as cod liver oil (in supplement form) because it allows a smooth transition from the aerobic to anaerobic pathway, or from burning fat to burning carbohydrates.
Lactic acid buildup in the muscles is not what causes pain when you work out too hard.  This buildup initiates a cascade of events which result in the production of prostaglandin E, which causes pain and swelling to occur.  Prostaglandin E can be inhibited by essential fatty acids, or fish oils in a supplement or whole food form, therefore decreasing the amount of pain and swelling occurring.

Protein is used to help in the synthesis of new tissue brought on by the axial loading, or weight bearing effects of training.  Protein is not used for energy unless the body runs out of its stores of carbohydrates or fats.  The recommended protein intake for a low activity athlete is 0.8g per kg of body weight.  Moderate activity requires 1.2g per kg of body weight, and high activity requires 1.8g per kg of body weight.   Vitamin B6 is required for the metabolism of proteins.

The following is a list of supplements beneficial to an athlete:

Note: a general rule for supplements is to try them for 2-4 weeks.  If you feel they are not working, stop using them.   If at that point you feel worse, they probably were working.

Vitamin C: aids in healing process by helping to synthesize collagen, epinephrine, and anti-inflammatory corticoids

Vitamin E: Helps to keep red blood cells intact during exercise  (consumption over 400 IU is toxic)

Calcium: Muscle cramping during activity could mean a need for calcium.  Increased physical activity improves the efficiency of calcium utilization.

Magnesium: Smooth muscle cramping while at rest (such as Intestines, and uterus).  A craving for chocolate may be indicative of a magnesium deficiency.  Magnesium can be found in anything green.

Phosphorus:  attributed to ATP formation and may have a role in the release of oxygen from the red blood cell.  High levels of phosphorus induce loss of bone calcium via the increased acidity of the blood.  Foods high in phosphorus are soda, coffee, and cottage cheese.

Potassium: Deficiency associated with muscular weakness and fatigue.   However it is hard to become deficient in potassium unless accompanied by vomiting and diarrhea.  It is not recommended to supplement with potassium because too much can lead to cardiac dysrhythmia.  Instead, eat one bananna or 4-6 ounces of orange juice per day.

Iron: exercise alters blood volume and muscle mass which increases the need for iron.  Female menstruating athletes, endurance anthlets, low body weight althetes and vegetarians are all prone to deficiencies in iron.

Chromium: helps in maintaining normal glucose metabolism by increasing insulin’s sensitivity to glucose.  May help in the enhancement of endurance, muscle development and growth.  If hypoglycemic, do not supplement with chromium as it makes insulin work better, dropping your blood sugar lower.

Zinc: linked to energy production in the muscle cell, also aids in the healing process.  Diet high in carbs are low in zinc

Adapted from lecture at NYCC by Dr. Mary Balliett D.C. on Clinical Nutrition