During running, all speed increases are intentional. What comes out unconsciously after training is strength.

But there is a kind of training called variable speed running. This is a rhythmic artificial speed change, which is mostly used to develop general endurance and improve aerobic metabolism and explosive power. Of course, some people use this kind of training to run to lose weight, and the effect is not bad.

Therefore, when running, you can deliberately speed up your speed, and then grasp the time to speed up according to your endurance.