"What Is Fitness?" Part 1: 10 Physical Skills (2024)

In this six-part series, Seminar Staff Head Trainer Jenn Hunter-Marshall explains CrossFit’s definition of fitness during the “What Is Fitness?” lecture presented at a Level 1 Certificate Course at CrossFit South Philly in 2021.

As first outlined in the “What Is Fitness?” article from 2002, CrossFit recognizes 10 general physical skills. They are cardiovascular/respiratory endurance, stamina, strength, flexibility, power, coordination, agility, balance, and accuracy.

1. Cardiovascular/respiratory endurance – The ability of the body’s systems to gather, process, and deliver oxygen
2. Stamina – The ability of body systems to process, deliver, store, and utilize energy
3. Strength – The ability of a muscular unit, or combination of muscular units, to apply force
4. Flexibility – the ability to maximize the range of motion at a given joint
5. Power – The ability of a muscular unit, or combination of muscular units, to apply maximum force in minimum time
6. Speed – The ability to minimize the cycle time of a repeated movement
7. Coordination – The ability to combine several distinct movement patterns into a singular distinct movement
8. Agility – The ability to minimize transition time from one movement pattern to another
9. Balance – The ability to control the placement of the body’s center of gravity in relation to its support base
10. Accuracy – The ability to control movement in a given direction or at a given intensity

You are as fit as you are competent in each of these 10 skills, and a regimen develops fitness to the extent that it improves each of these 10 skills.

Importantly, improvements in endurance, stamina, strength, and flexibility come about through training. Training refers to activity that improves performance through a measurable organic change in the body. By contrast, improvements in coordination, agility, balance, and accuracy come about through practice. Practice refers to activity that improves performance through changes in the nervous system. Power and speed are adaptations of both training and practice.

If your goal is optimum physical competence, then all 10 general physical skills must be considered and developed.