New to the gym, or not, a personal trainer can help determine a baseline for five measures of physical fitness. From there, use those numbers to track your progress and stay motivated.

What exactly does it mean to be fit? It's that feeling you have when you're strong, toned, lean, flexible and have the energy to go the distance. But when a feeling just isn't a concrete-enough measure, health and fitness experts track your fitness by looking at five key components. Are you fit in all five areas?

The five components of physical fitness are:

1. Body fat composition
2. Cardio-respiratory fitness
3. Flexibility
4. Muscular strength
5. Muscular endurance

Body Fat Composition

The American College of Sports Medicine (ACSM) defines body fat composition as the relative proportion of fat and fat-free tissue in the body (how much fat you have compared to muscle, bone and organs). The measurement gives you a baseline for comparison as you become more fit and lose weight. It's also a way to evaluate your risks for certain diseases like cardiovascular disease, diabetes and some cancers, all of which are linked to being overweight and obese.

There are several ways to measure body fat composition. The most reliable involves being weighed under water. More often, however, fitness professionals use calipers (a measuring tool that gently pinches skin folds) or a good old-fashioned measuring tape.

Cardio-Respiratory Fitness

Your cardio-respiratory fitness reflects the functional capabilities of the heart, lungs and muscles relative to the demands of specific exercises such as running or cycling. In other words, how well your heart and lungs work together to deliver oxygen to your body. The most official way to measure it requires the person to exercise at their maximum capacity while their respiratory gasses are also measured.

You can also monitor your heart rate while working out. You can wear a heart rate monitor, or simply take a pre-exercise pulse, count your pulse again during exercise and then evaluate the recovery heart rate. It's a good way to figure out how hard and what heart rate to aim for during exercise.


Flexibility refers to the degree to which a joint moves through a normal, pain-free range of motion. Flexibility can make a huge difference as we age. Not only can it make the difference between being able to get up and down from a chair, it can also be a reflection of quality of life since lack of flexibility can make all kinds of activities more difficult. There are lots of ways to measure flexibility, but the sit and reach test is most common in gyms.

Muscular Strength

Muscle strength refers to the amount of force a muscle can exert, in a single effort. How much weight can you lift? It's often measured on weight machines or by use of free weights or dumbbells.

Muscle Endurance

Muscle endurance is the ability of a muscle to perform a continuous effort without fatiguing. It's how long you can walk, run, cycle or do another activity before you get tired. It's often measured on the treadmill or stationary bike.

For the average person, these measurements might not mean a whole lot at the beginning of your new exercise plan, but as you continue working out, they might mean a lot more. As your body fat composition reduces and you're able to lift more, work out longer and harder and finally reach your toes, you'll be proud of your progress and motivated to keep on going.

Mike Ceja, CFP Certified Personal Trainer/Sports Therapist, reviewed this article.



American College of Sports Medicine
Getting a Professional Fitness Assessment
Jan 10, 2012
Written by Matthew Percia; Shala Davis, Ph.D., FACSM; and Gregory Dwyer, Ph.D., FACSM