Of course, this old tale has probably been embellished over the centuries. But the moral of the story is true. When you gradually introduce new challenges, your body adapts to handle the load.
Why Is Progressive Overload Important?
Once your body adapts to something new, you develop a tolerance. And when that happens, your body is resistant to change.
As an example, say you drink a cup of coffee every day for energy. After a while, you develop a tolerance for caffeine. Then you have to drink two cups of coffee to get the same energy boost.
Similarly, your body develops a tolerance for resistance training. At first, you gain muscle with little effort. But, over time, you have to increase your workload in order to continue gaining.
Progressive overload prevents your body from getting used to the stress of training. And that means you continue to grow.
Two Types of Progressive Overload
You’re reading this because your goal is to get stronger and increase muscle mass. But let’s pretend for a moment that you want to improve conditioning and burn fat. So you start a cardio program where you run a mile a day.
After a few weeks, running a mile feels easy and you’ve already lost 10 lbs. So you decide to run 2 miles a day. Then, in a few more weeks, running 2 miles feels easy. But this time you only lost 3 lbs. Eventually, you stop losing weight entirely, even though your conditioning slowly improves.
That’s because the overload is better suited to conditioning than fat burning. Therefore, you need to incorporate a second kind of overload that prioritizes fat burning over endurance. Such as an interval training program designed to burn fat.
In the same way, the goals of muscle strength and muscle growth are not always related. So if you only train for one, you eventually hit a plateau in the other. As a result, you need different types of overload to achieve ongoing gains in strength and growth.
1. Increase Load (Strength)
Like Milo and the calf, the classic example of progressive overload is a gradual increase in load. In other words, the amount of weight you lift. Most likely, this is how you’re used to training.
When you do this day after day, you see steady strength gains. However, as you reach your limits, getting stronger gets harder. So you are incentivized to change your form in order to lift more.
During a heavy squat, for instance, you tend to use a wider stance and place the bar lower on your back. This technique spreads the load to other muscle groups, allowing you to generate more power and lift more weight. Basically, you train your body to become more efficient at moving heavy weight.
Meanwhile, you take some of the load away from specific muscles like the quadriceps. Therefore your quads are no longer directly stimulated and do not continue to grow.
In this case, you get stronger without gaining muscle. And it shows that muscle strength and muscle growth are not always directly related. For that reason, you have to implement the second type of progressive overload to continuously improve.
2. Increase Intensity (Growth)
The second type of overload is about using less weight to do more work. In resistance training, the amount of energy you expend in a given time is called exercise intensity. And intensity increases when you do more work in less time.
As a simple example, consider the amount of work you do in a set of bench press. Work is equal to Force times Distance.
W = F x D
So let’s say you can bench press 250 pounds for 3 repetitions. And for simplicity’s sake, assume you move the bar a distance of 1 foot. Then the amount of work you do in that set is:
250 lbs x 3 reps x 1 ft = 750 ft-lbs
On the other hand, you can also press 200 lbs for 8 reps. So the amount of work you do in that set is:
200 lbs x 8 reps x 1 ft = 1,600 ft-lbs
As you can see, you did about twice as much work even though the weight was less. In addition, it takes less time to recover from lifting moderate weight. So you can take shorter rests between sets.
For instance, in a span of 5 minutes, you might only complete 2 sets with 250 lbs. But you can do 3 sets with 200 lbs. Therefore, the total amount of work you do in 5 minutes is:
750 ft-lbs per set x 2 sets = 1,500 ft-lbs
1,600 ft-lbs per set x 3 sets = 4,800 ft-lbs