Welcome to Part 2 of The Basics of Strength Training! In case you missed it, check out Part 1—Top 20 Words You Need To Know—to better understand the most common words used in strength training. All caught up? Great! Now let’s dig deeper into the actual laws of fitness part!
So what exactly is “fitness”? That is, what does it mean to “be fit”? According to the American College of Sports Medicine (ACSM), “fitness” is defined as “a set of attributes that people have or achieve that relates to the ability to perform physical activity.” (source)
So the real question is: How do you learn how to exercise? Lifting weights won’t help you run a marathon tomorrow; that’s not how the body works. You have to train your body according to your goals, specifically for the physical activities you want to perform.
In 1940, a doctor of endocrinology named Dr. Hans Selye formulated the theory of stress adaptation, a major component of medicine and physical fitness. The theory proposes three stages in how our body reacts to stressors (e.g. exercise, bacteria, outside influences) that upset the body’s balance (source): alarm, resistance, and exhaustion.
Alarm is your initial response to a stressor, such as sweating, rapid breathing, and elevated heart rate.
Resistance is when your body tries to adjust to the effects of the stressor. This is the purpose of physical conditioning: the body adapts to the stressor, making it less “stressful”. But the body will only adapt if the stressor disrupts the body’s balance, so you must keep challenging yourself by running longer or lifting more weight.
Exhaustion is when your body can no longer handle the stress and suffers an injury. This can happen immediately (acute) or occur repeatedly over time (chronic).
The 5 Laws of Fitness
There are five principles, or “laws”, that directly influence how your body adapts to stress from exercising. The goal is to combine all five laws of fitness to boost your health. If your training doesn’t cover all five—as most popular training methods don’t—then you’re keeping yourself from reaching your full potential.
Here’s what you need to know about each law of fitness in order to optimize your training.
This is the “bread and butter” of GAS. There are various ways you can overload your body: increase your load throughout your training, add more repetitions, or adjust your rest time or frequency. All these techniques can help your body adapt to stress. If you don’t increase your overload, you’ll reach a point where you won’t see any more progress (a.k.a. plateau).
*Injuries, poor recovery, and excessive soreness are signs of overtraining. If you experience these, take a week off, then readjust your training routine.
Your body adapts specifically to each exercise. For example, running and swimming produce different results than strength training. This principle also applies to the Central Nervous System (CNS): neuromuscular changes will occur over time as an adaptation to specific movement patterns. This is how some athletes react super-fast to certain situations without a second thought: their CNS system already knows what to do!
As much as people like to use genetics as an excuse, it does affect how the body adapts and performs. Some people are genetically predisposed to certain diseases, while others are genetically gifted for athleticism. That’s why it’s important to take this law into account. Even though we all have similar responses to exercise, the rate and magnitude of these changes will be determined by genetics.
Simply put, if everyone did the same exercise program, we wouldn’t all get the same benefits at the same rate or to the same extent. So group fitness students, take note: don’t expect everyone in your class to achieve the same results!
In conjunction with overload is progression, which states that adaptation to the stress of training is optimal when the stress is applied gradually. Pacing is key: apply overload too slowly and you won’t see improvement, but apply it too quickly and you’ll suffer injuries. Moderating your training with rest and recovery will also improve your progression and help your body adapt to stress faster.
This is essentially the opposite of overload. It’s what you see when someone has a cast removed. A limb that’s been in a cast will be atrophied after prolonged inactivity, so it will need more exercise to recover. You’ll lose your progress if you don’t train, so stay consistent. It takes less time to lose what you earned than it took to gain it!
Bringing It All Together
The human body is extremely adaptable; anything different you do will change it in some way. That’s why “everything works once”, at least until your body adapts and you plateau.
The point of the five laws of fitness is to fully consider your training goals. Not everyone wants to lift the heaviest weights, but some people need more than a brisk walk outside to get fit.
If you easily suffer injuries, need more from your fitness routine, or just want to understand how the body adapts to stress, then consider these five laws of fitness the next time you exercise. Combined, they will help you reach your goals to become strong and healthy!
Do you follow these laws of fitness? How have they affected your training? Share your thoughts and questions in the comments below, and be sure to share this article with your friends!