The machine allows the user to train under Earth's gravity multiplied by a certain number. The increased gravity increases a persons body weight, which they must build up their muscles to deal with, lest they have a hard time moving. Once the user returns to normal gravity, they enjoy the increased muscle they built up, and they feel much lighter and faster compared to how much they weighed in the increased gravity.
The first gravity machine Dr. Brief created was able to go anywhere between 1 and 100 times Earth's gravity. He later created an upgraded version of the machine at the request of Vegeta, which could go up to 300 times the Earth's gravity. After that machine was destroyed during Vegeta's training, it was rebuilt and upgraded to go up to over 400 times the Earth's gravity.
After a Gravity Chamber was built into Capsule Corp as a training room, it was once again upgraded to increase the room's gravity up to 500 times Earth's gravity.
The gravity machine is also complimented by training drones that target Vegeta with lasers, which he has to dodge in the enhanced gravity.
The first machine is used to help Goku train in his spaceship for the battle on Planet Namek. The machine goes haywire at one point while Goku is training under 50 times Earth's gravity, causing it to jump up to 100 times Earth's gravity by itself, forcing Goku to master it to the point where he does not even feel it. This remarkable coincidence helps Goku greatly while battling the Ginyu Force. It, along with the ship, are destroyed when Namek explodes.
In the Trunks Saga, an upgraded version of the machine is created to help train Vegeta. According to the Daizenshuu, this more powerful version can go up to 300 times Earth's gravity. It is destroyed in the same Saga, during training. However, it is subsequently rebuilt and Vegeta later increases the forces to over 400 times Earth's gravity.
Vegeta's original Gravity Machine was originally located inside his Capsule corporation spaceship which was demolished during his training, though a new one was built which he used until acquiring the Super Saiyan form. At one point, Yamcha uses Vegeta's gravity machine in a jealous attempt to emulate his training but he is overwhelmed by the level of gravity and is amazed Vegeta could actually endure such high gravity.
After marrying Bulma, a Gravity Chamber was installed within the Capsule Corporation as a training room for Vegeta though Trunks would also train there with Vegeta during the Great Saiyaman Saga for the World Martial Arts Tournament. Trunks at first struggled with the high Gravity in his base form, causing him to transform into a Super Saiyan to move around more easily to Vegeta's amazement that his young son had acquired the form much earlier and far easier than either his counterpart or Vegeta himself. The Gravity Chamber replaces the old Spaceship-based Gravity Machines.
During his battle with Pui Pui, Vegeta reveals that he used his Gravity Chamber to train under even higher gravity (in Dragon Ball Z: Buu's Fury, it is said that he trained under exactly 450 times Earth's gravity) and states that Pui Pui is foolish to think that his home planet of Zoon, which had 10 times gravity, could help him win, however Vegeta had trained under 500 times normal gravity (additionally Vegeta was born on Planet Vegeta which had the same level of gravity as Zoon).
In Dragon Ball Z: Battle of Gods and the God of Destruction Beerus Saga, Vegeta uses the Gravity Machine for training. Vegeta trains under 150 times gravity normally. In Dragon Ball Super, Vegeta gets interrupted by a staff member of Capsule Corporation and gives him a call from Bulma to go to her birthday party though it is strongly implied the gravity was turned off before she entered the chamber as a safety measure installed by Bulma or her father to protect Capsule Corp. employees and members of the Brief family unaccustomed to high gravity training.
In the anime during the Universe 6 Saga, Vegeta notes the super-heavy outfits provided to him and Goku by Whis were so heavy that the strain it caused him was even greater than the intense Gravity produced by Bulma's latest Gravity Chamber, indicting that she is responsible for developing the Gravity Chamber used by Vegeta in Dragon Ball Super.
Vegeta is also shown using the room to train during the "Future" Trunks Saga and briefly stands in front of the door to the chamber while swearing he will never forgive Goku Black for murdering his wife's future counterpart.
During the anime Universe Survival Saga, Bulma and the Pilaf Gang utilizes the Gravity Chamber as a simple exercise room, with Bulma having taken up exercising while pregnant with her and Vegeta's unborn daughter as she heard it was healthier for the baby if the mother took up exercising while pregnant (presumably this would apply even more for her hybrid Saiyan daughter, given the warrior race's aptitude for physical exertion).
During the Galactic Patrol Prisoner Saga, Goku and Vegeta both use Vegeta's Gravity Chamber for sparring. However their training is interrupted by the Galactic Patrol attempts to take Good Buu leading to their abduction and recruitment by Merus to deal with the escaped criminal Moro.
Video Game Appearances
Goku uses the Gravity Machine inside his spaceship to train during his journey to Namek in Dragon Ball Z II: Gekishin Freeza, Dragon Ball Z: Super Saiya Densetsu, and Dragon Ball Z: Goku Gekitōden. He must train under 20, 50, and 100 times Earth's gravity in Gekishin Freeza and under 10, 20, 30, 40, 50, and 100 times Earth's gravity in Legend of the Super Saiyan.
The Gravity Chamber appears as a training room in Super Dragon Ball Z.
It also appears as a Support Card in Dragon Ball Z: Legendary Super Warriors, where it can be used to reduce an opponent's speed.
In Dragon Ball Legends, the Gravity Chamber appears as a Training Location Items that boost success in Training. The Training Locations include Gravity Chamber (50G) represented by the Gravity Machine on Goku's Capsule Corporation spaceship, Gravity Chamber (150G) represented by Vegeta's Gravity Chamber within the Capsule Corporation, and Gravity Chamber (300G) represented by the Gravity Machine on the Capsule Corporation spaceship used by Vegeta during his training to become a Super Saiyan.
"The other day I went into Vegeta's training room on accident. I was totally squished by all the gravity and came out looking like a pancake! Yikes!"
— Bentora in Dragon Ball Xenoverse 2
In Dragon Ball Xenoverse 2 while investigating the Capsule Corp. time rift, Male Majin Time Patroller Bentora reveals to the Future Warrior that one day he accidentally went into Vegeta's gravity chamber by mistake and was totally squished by the intense gravity and came out looking like a pancake (it is implied he only survived due to his Body Manipulation, allowing him to endure his body being squished in such a manner). Bentora refers to the Gravity Chamber as Vegeta's training room.
Additionally, while working as an Instructor, Vegeta notes Conton City's gravity is weaker than Planet Vegeta's and wonders if he and other Saiyan instructors such require their students to train under ten times Conton City's gravity to compensate for them being accustomed to a place with such weak gravity though it is unclear whether this would involve artificial gravity generated by a Gravity Machine or simply having them train in an area with ten times the Earth's gravity such as Planet Tuffle.