In Dragon Ball stories, it is common to see the main characters train in their quest to become the most powerful, and although most of the plot is fantasy, there are also elements that have some scientific basis. With this in mind, the training that Goku and Vegeta undergo is not entirely possible, but the principles are legitimate.
Goku and Vegeta are Super Sayajines who face great threats and participate in fighting tournaments, so getting stronger is a key part of their lives. That is why they spend a good part of the series in training, and a closer look at this activity reveals that the tools they use have some scientific support even when their intensity levels are well above what can be achieved (via ScreenRant).
According to Dragon Ball official site, higher gravity and the Spirit and Time Room would be beneficial as a training method. And it is that an article is shown on the site where Masayuki Sato, professor of science and specialized writer of biology, interviewed professor Yutaka Hirata who is a specialist in systems neuroscience and bioinformatics engineering, and affirmed that what he is really training in a high gravity is the mind.
He noted that increasing gravity optimizes neural networks and therefore improves the acquisition of motor skills, so the key to improvement is not in gravity, but rather the key is in increasing the synaptic transmission rate to minimize the movement errors.
The series also shows training in the Room of Spirit and Time, which is an empty and immense dimension on an isolated existential plane that is known and is shown as a completely white room with a bright environment. According to Professor Hirata, intense light also has a positive impact on the acquisition of motor skills in scientific experiments.
In this way, the place and methods of the actions in training in the Dragon Ball series are not as far-fetched as it might seem, this despite the fact that humans would not withstand seriousness like those shown in Dragon Ball, which are 100G and 300G.
And well, whatever is a fact is that Dragon Ball has inspired many fans to have a healthier life and exercise more with characters like Goku and Vegeta always striving to give their best.