Don’t Study Physics

In our company SmartCoach Technologies , we develop tools for tracking strength exercises. This requires knowing the physics of training devices, measuring mechanical variables, and calculating physical quantities – force, speed, power, etc.

Because of that I usually end up talking about those concepts with people in the field. And, more often than it should, I am being told that this is “Engineers’ stuff”. I find this a worrying conundrum in Sport Physiology. How come one is using a tool without understanding its working principle?

The good news is, Physics doesn’t need to be studied to master it: it has to be understood. If you need to memorize it, you aren’t doing it right.

Physical entities are linked to each other like gears in a well oiled mechanism. Once understood that gear A is meshed with B which is meshed with C, there is no need to remember that turning gear A spins gear C – it’s a logical consequence. 

Also, Physics is consistent: if x is measured in bananas and is multiplied by an area (m²), the result will be in bananas x m².

In fact, Physics Rule # 1 is to always use measurement units. This and the consistency principle unlock much of its knowledge. Let’s see it in practice.

There are two families of independent variables. In one there is impulse (Ns) and force (N). In the other, displacement (m), speed (m/s), and acceleration (m/s²). Note how they are linked to each other by multiplying or dividing by time (mathematically: time integral and derivative).

Their units tell right away how to calculate one from another: since speed is measured in m/s, it can only be computed as displacement divided by time.

This brings us to Rule # 2: write in formulas. Not only it is more efficient, it also helps the logical flow of calculations. Example: how much is 1km/s in m/s? Just write it in formulas and units: since 1km = 1000m and 1h = 3600s, 1km/h = 1000m/3600s = 1m/s / 3.6.

Last but most important, Rule # 3: search for relatable examples of Physics concepts around. This will help you assimilate them. Let’s take a classic, Newton’s II Law: Force = Mass x Acceleration.

While in a fast elevator, have you ever held a bag and felt it heavier at the beginning of the ride? This is Newton’s Law: when the elevator begins the ride, velocity increases from zero to the ascent speed, resulting in a positive acceleration. That, multiplied by the bag mass, is the extra downward force you feel.

Applied to sports, that’s why muscle hypertrophy is not always a good idea in a football player: it improves force but also mass, so the sprinting ability (Acceleration = Force/Mass) won’t improve.

For all practical purposes, understanding a few Laws and applying these rules is all it takes to master Physics in Sports Science. As far as you don’t study it, but understand it.

What do you think? Share your thoughts with the hashtag #DoNotStudyPhysics