Monday, December 7, 2015

The Forgotten Factors Contributing to Pathokinematics - Part II

In the first part of this blog series, we talked about the role of hydration on movement.  Today, we will take a look at environmental factors as well as nutritional factors.

Heat and Humidity
When exercising in extreme heat and humidity, the body requires a much greater intake of fluids to maintain health and wellness.  Without the required intake of fluids, athletes are particularly subject to heat related issues, including serious illness that can even require immediate medical treatment. 
Heat exhaustion is the most common type of heat illness and is caused by decreased blood volume due to dehydration. With heat exhaustion, an individual can experience:
  • Dizziness
  • Headaches
  • Nausea
  • Profuse sweating
  • Cool or clammy skin
  • A rapid or weak pulse
  • A body temperature that is at or slightly above normal.

If you have these symptoms, you should try to cool down as quickly as possible.  Body cooling can occur through conduction, convection and evaporation.  Evaporation is the most critical defense the body has to overheating.  It occurs when the body’s sweat changes on its surface from a liquid to a gas, which then cools the skin.  The relative humidity in the air surrounding a person’s body is the most important factor in determining how effective evaporation is for cooling the body’s core temperature. 

According to the National Oceanic and Atmospheric Administration’s (NOAA) Heat Index Chart, temperatures and humidity levels in combination below 80 degrees and 40% respectively are of no concern.  However, at 88 degrees Fahrenheit and 40% humidity, the heat index is at 88 and caution is needed.  If the temperature stays at 88 degrees Fahrenheit and the relative humidity rises to 75%, conditions are dangerous.


This is important to athletes and others who are exposed to heat while required to also exert themselves because the body’s most important mechanism for cooling as mentioned is evaporation.  As the heat index rises, and the humidity levels rise, the air cannot absorb as much moisture off the skin and so evaporation slows or even stops, eliminating the body’s ability to cool itself in that way.  When conditions are extremely dangerous, or when an athlete overexerts him or herself and fails to hydrate and cool off properly during exercise or activity, heat stroke can occur.  The official definition of heat stroke is when the body’s core temperature exceeds 105 degrees Fahrenheit.  Heat stroke can result in death if not treated immediately.  Other heat related issues that athletes can encounter include sunburn and heat cramps, which are painful spasms in the legs and abdomen.


It is important to remember that nutrition has a significant impact on performance, recovery and body composition.  There are basically two types of food:  energy dense foods and nutrient dense foods.  Energy dense foods are higher in calories relative to the size or volume of the food.  These foods should be consumed with caution because it is easy to provide the body with too many calories at times when they may not be needed for energy production.  Foods in this category include raisins, cheese, whole milk, butter, French fries, burgers, sweets, energy bars and soft drinks.  Nutrient dense foods however are bulkier and take more time and energy to eat.  These include grapes, other whole fruit, whole and uncooked raw vegetables, and lean meats, fish or other proteins, such as beans and legumes.

Many athletes discount the role of nutrition in sports performance and staying strong and injury free.  So many people say they exercise so they can eat and drink whatever they like whenever they like.  Then they are confused when they feel tired, lethargic and don’t get the results they desire in the gym, on the field or on the road.  In addition to facilitating increased performance, nutrition also plays a role in staying injury free.   Nutritional needs vary by the type, volume, frequency and intensity of training.  If you are training more, nutritional needs are greater and it is even more important to pay attention to the type, quality and timing of fuel intake.   Overall, athletes should attempt to do the following to maintain a healthy body composition, maximize performance, and reduce the likelihood of injury and the fatigue that can lead to injury via pathokinematics:

  1.  Remove as many processed foods as possible from the diet
  2. Concentrate on getting enough whole fruits and vegetables and lean protein
  3. Be careful with starches and sugars, emphasizing them in your diet primarily during and immediately after intense training.[ii]

Another consideration for athletes is the balance between carbohydrates, protein and fat.  Carbohydrates are necessary to replenish glycogen stores that are used up during intense exercise which is discussed further in a later section.  Therefore, carbohydrates should be consumed immediately (within the first 30 minutes) after long or intense workouts in order to replenish glycogen stores and refuel for the next workout.  Protein must be consumed in order to build muscle and other tissue in the body that is broken down during training.  Finally, fats are also required in a healthy balanced diet (despite some commonly held thought) to help maintain the immune system and enable the body to process protein and carbohydrates for use in cells.

Of course, vitamins and minerals are also needed for a well functioning body.  Most micronutrients are found in a well balanced, varied diet where foods are consumed in as close to their natural state as possible.  If your athlete is not getting a well balanced diet for some reason, sometimes a multivitamin is beneficial, though it should be remembered that vitamins and minerals taken in pill form are never as readily used by the body as those found in a natural diet of healthy, lean, whole and unprocessed foods.

Vitamins and minerals that are especially important for athletes and a few of the ways they impact performance are listed here:

 Vitamin A – Improves immune function; promotes skeletal growth; important for vision

Sources:  Beef liver, green, orange and yellow vegetables

Vitamin B1 – (Thiamin) helps convert starches and sugar into energy, promotes a strong heart muscle, prevents fatigue

Sources:  whole wheat, dried yeast, oatmeal, peanuts, port, bran, enriched rice, sunflower seeds, soybean sprouts

Vitamin B6 – Aids metabolism of protein, carbohydrates and fats, aids in keeping chemical balance between blood and tissue, builds hemoglobin

Sources:  brewer’s yeast, wheat bran, wheat germ, organ meats, beef, avocados, bananas, milk and eggs

Vitamin B2 (Riboflavin) – aids in releasing energy to body cells, enables use of fats, proteins and sugars

Sources:  Dairy, liver, kidney, yeast, leafy greens, fish, eggs

Vitamin B12 – Promotes use of protein, fats and carbohydrates, helps in formation of red blood cells, helps nervous system

Sources:  Liver, beef, pork, eggs, dairy, shellfish

Vitamin C – Required to absorb iron, some proteins and folic acid, prevents oxidation of other vitamins, aids in metabolism of amino acids and calcium, strengthens blood vessels and maintains bone density, promotes stamina, aids in healing

Sources:  citrus fruits, berries, green and leafy vegetables, tomatoes, cauliflower, potatoes (white and sweet)

Vitamin D – helps strengthen bones and helps protect the body against osteoporosis and cancer; maintains nervous system and heart action; modulates neuromuscular function, reduces inflammation

Sources:   sunlight on human skin, fish, some fortified foods, light-exposed mushrooms

Vitamin E – protects the body’s store of vitamin A, tissues and fat from destructive oxidation; aids blood flow to the heart, regulates protein and calcium metabolism

Sources:  Soybeans, vegetable oils, broccoli, Brussels sprouts, leafy greens, whole wheat, wheat germ, whole grain cereals, eggs.

Calcium—helps promote weight loss, build muscle tissue and strengthens bones; helps protect the body against osteoporosis

Sources:  Dairy, soybeans, sunflower seeds, legumes, sardines

Magnesium – aids in converting blood sugar into energy, helps regulate body temperature, promotes absorption and metabolism of other minerals, and activates enzymes for metabolism of carbohydrates and amino acids

Sources:  nuts, figs, seeds, dark green vegetables, wheat bran, avocados, bananas

Iron – present in all cells, one of the parts of hemoglobin which carries oxygen to the tissues by blood circulation

Sources:  liver, meat, raw clams, oysters, oatmeal, nuts, beans, wheat germ

Iodine – helps burn fat, aids in absorption of carbohydrates from the small intestine, regulates energy production

Sources:  kelp, seafood, vegetables

Copper – facilitates iron absorption, promotes protein metabolism

Sources:  shrimp, beef liver, whole wheat, prunes, nuts, raw oysters

Zinc – aids in metabolism of carbohydrates

Sources:  eggs, cheese, beef, pork, wheat germ, brewer’s yeast, pumpkin seeds, popcorn

Niacin – used with other vitamins to convert carbohydrates into energy

Sources:  liver, lean meat, whole wheat, brewer’s yeast, wheat germ, fish, eggs, roasted peanuts, poultry, sesame seeds, nuts.

Fiber  - lowers risk of diabetes and heart disease, lowers blood cholesterol, maintains healthy digestive system, helps control blood sugar, aids in weight loss

Sources:  fruits such as apples and citrus fruits, vegetables such as peas, beans, carrots, whole grains, wheat bran, legumes, nuts, oats, barley[iii]

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis and author of a college textbook on this subject.  He serves as the National Director of Sports Medicine for Physiotherapy Associates, is a Safety Council Member for USA Cheer National Safety Council and associate editor of the International Journal of Athletic Therapy and Training. 

[i] NOAA, National Weather Service Office of Climate, Water, and Weather Services; “Heat:  A Major Killer,” 1325 East West Highway, Silver Spring, MD 20910 web site;
[ii] Going Long:  Training for Ironman Distance Triathlons, Joe Friel and Gordon Byrn, The Ultrafit Training Series, Velo Press, 2003, pages 10, 187.

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