Carbohydrate Classification

Carbohydrate classification can be easily understood as simple carbohydrates (monosaccharides and disaccharides) and complex carbohydrates (polysaccharides). Simple carbohydrates provide your body with immediate energy (rapid increase in blood sugar) and is found in fruits, vegetables, and dairy products. Complex carbohydrates provide your body with longer and more sustained energy (slow increase in blood sugar) and is found in starches and fibers. Both simple and complex carbohydrates eventually break down into sugar (glucose) and provide the primary source of energy for your body.

Scapular Protraction and Retraction

The resting position of the shoulder blade (scapula) is generally ~2 inches away from the spine, between 2nd and 7th rib. Protraction and retraction of the shoulder blade can be described simply as moving away and toward from the center of the body, however, ligaments and muscles surrounding the collar bone (clavicle) and rib cage (thorax) cause moderate tilts and rotations. As the shoulder blade glides along the rib cage, the joint where the sternum and collar bone meet (SC) protracts/retracts and the joint where the shoulder blade and collar bone meet (AC) rotates. Proper interaction of these joints decreases the chance of impingement and/or rotator cuff compression from shoulder blade alteration (scapular dyskinesis).

Optimizing the Circadian Rhythm

Our intrinsic body clock (circadian rhythm) regulates a complex series of rhythms in sleepiness and alertness. The individual period of the endogenous clock is usually ~24 hours and is normally assigned to match the times when the sun goes up and when the sun goes down (environmental rhythm). For the most part, our “body clocks” are internally generated, however, they can be modified by external cues such as sunlight and temperature. For example, making your bedroom cool, dark, and quiet (~60-65F) optimizes release of melatonin, the natural hormone that signals the body to go to sleep.

Sex Differences in Q-Angle

Women naturally have wider hips compared to men. This significantly impacts the angle from the hip (anterior superior iliac spine) to the knee (midpoint of the patella) and overall alignment of the knee joint. Knee collapse (valgus) may be more prevalent in individuals with a greater Q-angle and can result in “runner’s knee” from maltracking of the patella.

The normal range for women is ~17 degrees and men ~14 degrees, relative to the tibial tubercle and midpoint of the patella.

Pronation and Supination in Gait

During the normal walking cycle (gait), the feet naturally supinate and pronate. People with low arches may excessively pronate and experience plantar fasciitis, tendinitis, and pain in the arches. Excessively supinated feet are more likely among people with high arches and often lead to joint problems and tendinitis at the forefoot and big toe.

Complete Proteins and Incomplete Proteins

Proteins are combinations of amino acids used for growth and repair of bodily tissues. These combinations are selected from 20 different amino acids, 9 needing to come from the diet (essential) and the other 11 naturally produced in the body (non-essential).

Red meats, poultry, milk, eggs, and fish contain what is called complete proteins. Complete proteins satisfy the body’s protein requirements by including all the essential amino acids in the right portions.

Individual plant-based proteins, excluding soy, contain what is called incomplete proteins. Incomplete proteins lack in the body’s protein requirements by missing one or more essential amino acids.

However, these incomplete proteins can be made up by having numerous incomplete proteins together. So, for individuals who do not incorporate meat and dairy in their diet, a wide selection of plant-based foods can satisfy protein requirements.

Acceptable Macronutrient Distribution Range (AMDR): 15-25% of calories.

Water-Soluble Vitamins and Fat-Soluble Vitamins

Vitamins have two classifications: water-soluble and fat-soluble.

Water-Soluble Vitamins: do not store in your body and need to be taken daily.

B1 (Thiamine)
B2 (Riboflavin)
B3 (Niacin)
B6 (Pyriodoxine)
B12 (Cyanocobalamin)
Vitamin C (Ascorbic Acid)
Folic Acid
Fat-Soluble Vitamins: do store in your body and do not need to be taken daily. These vitamins dissolve in fat and remain in the body for long periods of time.

Vitamin A
Vitamin D (Calciferol)
Vitamin E (Tocopherol)
Vitamin K (Menadione)



Braking Force in Top Speed

After the first few meters of acceleration, your torso moves from a forward lean to a vertical position as you reach your top speed. Once at top speed, your goal is to minimize contact with the ground by getting your feet down quickly and driving the ground away. Slower sprinters often land their feet too far ahead from their hip (~12 inches), whereas faster sprinters land with their feet closer (~6 inches). For maximum speed, it is best to have your feet on the ground as little as possible (⬇️ braking force) while applying maximum amount of force during extension (⬆️ propulsive force).