The Navy SEAL Physical Fitness Guide - Human Performance

10 Overview of Physical Fitness

Figure 1-1. Muscle Fiber Composition and Maximal

Oxygen Uptake Values for Various Athletes by Sport

Figure adapted from: Exercise Physiology: Energy Nutrition and Human Performance, McArdle WD, FI Katch, VL

Katch. 4th edition. 1996. Williams and Wilkins Publishers.

Principles of Physical Training

The goal of any training program is to improve performance. You are unique in

terms of your excellent physical condition and your dedication to further enhancing your

fitness. The four principles that apply to all physical training programs are discussed below.

Overload

According to this principle, exercise must be done at a higher level than usual to

bring about various training adaptations. Once the body has adapted to the higher level of

exercise it will function more effectively and efficiently. The overload can be obtained

by manipulating various combinations of exercise frequency, intensity, duration and

type of exercise. Increasing intensity, duration and frequency can be helpful for running,

cycling or swimming, and increasing resistance and repetitions can improve strength

training.

Cross Country Skiers

Long Distance Runners

Swimmers

Weight Lifters

Wrestlers

Sprinters

Recreational Athletes

Maximal Oxygen Uptake

40 50 60 70 80 90 100

(ml/kg/min)

Slow Twitch Fibers

20 40 60 80 100

(%)

SEALs