eli5: what is the science behind a hypothetical workout?


If one were doing 3 sets of 20 push-ups per minute(with a minute or so break between them), that would do more to build strength/muscle than doing 100 push-ups over the course of a few hours, just at a comfortable pace, right? Even though you’re actually doing less? Or am I wrong? Either way, why?

In: 8

Let’s start with a question. Why does working out grow muscles at all? When you workout you’re actually causing your muscle fibers to become damaged on the microscopic level. As you rest, your body naturally repairs these damaged muscles fibers causing you to become stronger as a result. So, there is a correlation (to a certain extent at least) that causing more microscopic damages to your muscles will have a better result. Now, just doing more of something means nothing, the time in which it is done is also important when you look at putting stress or strain on something. For example, eating 3,000 calories in a day is not that bad, but eating 2,000 calories in one sitting is almost unbearable for most people. So, in short, doing 60 pushups in 3 minutes will cause more microscopic damages to the muscle than doing 100 over the course of 2-3 hours, resulting in more muscles growth (assuming that your body is given adequate rest).

It’s complicated, because there are a few different ways that exercise causes strength and muscle gains. First, there is just putting your muscles under tension with a load. Second, there is causing muscle damage that gets repaired. Third, there is metabolic stress that causes a build up of waste products. Each of these things causes somewhat different responses that all help you get stronger.

So, comparing your two hypothetical workouts. The 100 push ups would be more total tension on your muscles than the 60 push ups. But the overall lower intensity means less metabolic stress. And both seem like they would cause muscle damage. In short, they’re both probably going to give you the same results, at least initially.

That really depends, but when it comes to weight lifting and muscle growth it’s microtrauma that causes muscle hypertrophy. I.e. you hurt your muscle fibers, and as a response they heal and grow back stronger than before

Bottom line is you need to get at least somewhat close to your limits to actually force your body to adapt. Doing 1 pushup every couple of minutes is not going to challenge anything other than your patience.

The type of adaptation your body makes will depend on what limits you’re pushing. If you’re pushing the limits of your endurance, your endurance will get better. If you’re pushing the limits of your strength, your strength will get better (assuming your nutrition and recovery are also adequate).