Any endurance athlete, and especially an Ironman triathlete, should have one very specific physical objective during a triathlon: to maximize wattage

(power) and speed (velocity) while simultaneously minimizing muscular fatigue and depletion of energy stores. This is the science of triathlon. Let’s call this lofty objective in the science of triathlon the “Triathlete’s Holy Grail” or THG.

All particulars aside, the athlete who achieves THG the most efficiently will be the first to cross the finish line. The athlete who only achieves the first \part of this goal, maximizing wattage and speed, will accomplish a big ol’ DNF (did not finish), while the athlete who only achieves the second part of this goal, minimizing fatigue and energy store depletion, will accomplish a FLFL (cross the finish line with a flashlight).

Applying a combination of the science of triathlon - basic biomechanics and exercise physiology - to the three legs of the triathlon (swim/bike/run), an athlete can accomplish the holy grail with optimum efficiency.

So in this article, I’ll explain how to use the basic biomechanical relationship between mechanical levers and torque to positively affect three keys to efficiency in the three specific components of swimming, biking and running. Next week, I’ll teach you more science of triathlon, and how to use the basic physiological relationship between the body’s energy systems and muscle fibers to prepare for peak performance.

First, let’s briefly discuss the relationship between a mechanical lever and torque.

The human body is a perfect example of a series of levers (bones) that are attached to different points of rotation (elbow, knee, hip, back, etc.). For

example, imagine that you are holding your running shoe in your hand, with

your arm outstretched completely away from your body and completely straight at the elbow. In this case, the shoulder is the center of rotation, the lever is the length of the arm between the shoulder and the hand, and the force is the weight of the shoe.

We can say that the weight, or the force, of the shoe that you are holding away from your body is producing a torque at the shoulder. The torque in the shoulder is found by multiplying the length of the lever (the arm) and the force (the shoe’s weight). Therefore, we can decrease torque in the shoulder by either decreasing the weight of the shoe or decreasing the distance of the lever arm (amputation is never an option in physics problems). For example, if you shoe weights 1lb and your arm is 3ft long, the shoe is producing a torque at the shoulder of 3 foot lb’s. But if you bend your arm, so that it is 2ft long, the shoe only produces 2 foot lb’s of torque. Or if you lighten your shoe to 1/2 lb but keep the arm at 3 feet, the shoe produced 1.5 foot lb’s of torque.

Here’s where some people get confused. The lever arm length is not determined by distance of the lever itself, but rather by the perpendicular distance from the point of force application to the center of rotation.

Therefore, torque in the shoulder can be decreased simply by dropping the arm down a few inches, or, as in the example above, bending the arm.

When the arm is shorter, you can drop a straight line down from the shoulder, and then another straight line over to the new location of the

shoe. The second straight line would be the new lever arm. So you can pretty much bring torque down to nothing at all by simply dropping the arm holding your shoe all the way down to your side. With your arm at your side holding the shoe, there is no rotational torque on your shoulder at all, just the weight of the shoe pulling straight down on the shoulder (and that’s not rotational torque, just a downward force).

Now let’s quickly assume the arm is back up completely straight at the side holding the shoe, and the shoe is producing a downward torque on the shoulder. There is one more source of torque: the torque in the opposite

direction needed to keep the arm up. As you may have guessed, this torque is produced by the muscle itself, or, in this case, the rotator cuff and deltoid muscles. By contracting, or shortening, they produce a torque at the shoulder joint that opposes the downward torque of the shoe.

So why the heck is this geek-speak important for triathletes and the science of triathlon? Here’s why: because the amount of torque produced in a joint determines how much force the muscles must produce to resist that torque.

And by minimizing torque production at a joint in one direction, a triathlete can minimize fatigue, and by maximizing torque production at a joint in the opposite direction, an endurance athlete can maximize power and velocity. As you can see, this is crucial in pursuing the the holy grail of triathlon  - the first part of which is maximizing wattage and speed.

Next week, I’m going to tell you exactly how you can use the concept in science of triathlon that you just learned to either minimize the “bad” torque that can cause injuries or maximize the “good” torque that can make you a faster triathlete.