Req 1a — Physical Fitness
What does it mean to be physically fit? You might picture a professional athlete or a bodybuilder, but physical fitness is not about extremes. A physically fit person is someone whose body works well for the life they lead. They have the energy, strength, and endurance to handle daily activities and still have something left for fun, emergencies, and unexpected challenges.
The Four Pillars of Physical Fitness
When experts talk about physical fitness, they break it down into four measurable components. A truly fit person has a healthy balance of all four.
Cardiorespiratory endurance is your body’s ability to supply oxygen to your muscles during sustained physical activity. If you can jog for 20 minutes without feeling like you are going to collapse, your cardiorespiratory system is doing its job. Activities like running, swimming, cycling, and even brisk walking build this kind of fitness.
Muscular strength is the maximum force a muscle or muscle group can produce in a single effort. Think of lifting a heavy backpack off the ground or pulling yourself up onto a ledge. You do not need to bench press 200 pounds — you just need enough strength for the demands of your life.
Muscular endurance is the ability of a muscle to keep working over time without giving out. Push-ups, sit-ups, and holding a plank are all tests of endurance. On a long hike, it is your leg endurance that keeps you moving mile after mile.
Flexibility is how far your joints can move through their full range of motion. Touching your toes, reaching behind your back, and rotating your trunk all depend on flexibility. Good flexibility reduces your risk of injury and helps you move more efficiently.
What Physical Fitness Looks Like in Real Life
A physically fit person does not have to look a certain way. Fitness shows up in how you feel and what you can do:
- You can carry groceries up the stairs without getting winded.
- You can play a full game of basketball, soccer, or ultimate frisbee and still walk home.
- You recover quickly after hard physical effort.
- You sleep well and wake up feeling rested.
- You can handle an unexpected physical challenge — like running to catch a bus or helping move furniture — without getting hurt.

Body Composition — The Fifth Factor
Some fitness experts include body composition as a fifth component. Body composition is the ratio of lean tissue (muscle, bone, organs) to fat in your body. A healthy body composition means you have enough muscle to support your activities and enough body fat to protect your organs and provide energy reserves — but not so much that it slows you down or puts stress on your heart.
Body composition is influenced by genetics, diet, and activity level. It is not something you can change overnight, but regular exercise and balanced nutrition will move it in a healthy direction over time.