John was the first to leave, running towards the Kame House, followed by Yamcha and Krilin, who were led by Master Roshi.
However, this method of running was not very effective for their current strength levels, and it would be more efficient to fly back to West City and have Bulma quickly prepare the gravity chamber for training.
So, John said to Bulma, "They're running for training, but you don't need to. Let's fly back to West City, and you should focus on getting the gravity chamber ready as soon as possible."
Bulma asked, "Is the gravity chamber really that effective for training?"
"Of course," John replied. "With adjustable gravity from 1 to 100 times Earth's gravity, imagine how much stronger you'll become if you can fully adapt to 100 times Earth's gravity. Even at 10 times Earth's gravity, your physical abilities and bone strength will significantly improve."
"In martial arts tournaments, when skill levels are similar, what matters most is who has greater strength and speed," John added.
After hearing John's words, Bulma muttered to herself, "If that's the case, I should indeed hurry up and get the gravity chamber ready. I'll also give one to Yamcha later."
John was speechless at her response, but he couldn't stop her. After all, they were all friends, and it would be unreasonable to feel jealous of their friends' strength increasing.
It was a pity for Tenshinhan, as by the 22nd World Martial Arts Tournament three years later, he would likely not be able to defeat Yamcha as overwhelmingly as depicted in the manga.
After bidding farewell to Master Roshi and the others, Bulma piloted the plane with John, Oolong, and Launch, heading back to West City.
Upon returning home, Bulma immediately immersed herself in her laboratory, working on the final touches for the gravity control room.
However, the first version of the gravity control room couldn't achieve 1 to 100 times Earth's gravity; it could only adjust up to 1 to 10 times Earth's gravity due to material limitations. (1 times Earth's gravity is the standard gravity on Earth.)
But Bulma had already begun testing new materials for the next version, aiming to create a gravity control room capable of adjusting gravity from 1 to 20 times Earth's gravity in the near future. She planned to gradually upgrade it until she could manufacture the 1 to 100 times Earth's gravity control room.
More than a month after returning to West City, the first gravity control room was finally set up in Bulma's garden.
John was thrilled to test the gravity control room, and he found that at 4 times Earth's gravity, he already felt the pressure. However, with some training, he could fully adapt to it.
John believed that once he completely adjusted to 10 times Earth's gravity, his strength would significantly increase.
Currently, without a power detector, John wasn't sure of his exact power level, but he estimated it to be around 300, while Goku's power level was around 250.
With this strength, defeating a single Piccolo Daimao was not a problem. But who was Piccolo Daimao? The real challenge lay ahead with Frieza. Therefore, John was determined to become a Super Saiyan before facing Frieza.
If he couldn't transform into a Super Saiyan, he would have to focus on improving his base power level. Deep down, John wasn't sure if he could transform into a Super Saiyan in time.
However, thinking alone wouldn't help, so John began his training in the gravity chamber.
Initially, John had planned to bring the gravity chamber back to his home for training, but he soon realized that the power consumption of the gravity chamber was too high. With his limited financial resources, he couldn't afford to power the gravity chamber for long, so he shamelessly decided to train at Bulma's house.
Four times Earth's gravity...
Five times Earth's gravity...
...
Ten times Earth's gravity...
By the end of the second year, John had already adapted to ten times Earth's gravity in the gravity control room. Why was his progress so slow compared to Son Goku, who quickly adapted to 100 times Earth's gravity?
The reason was that John hadn't utilized the Saiyan ability to recover and increase strength after being severely injured. While this method could significantly improve his strength, it had limitations, and it was best to use it only when necessary.
John moved swiftly in the ten times Earth's gravity environment, surrounded by countless floating attack weapons firing lasers at him.
The lasers bounced off various emitters, attacking John from all directions. He constantly dodged and weaved through the laser beams.
Finally, drenched in sweat and exhausted, John fired a ki blast to neutralize the laser beams and completed his training.
Turning off the gravity switch, John took a deep breath and stepped out of the gravity control room. With less than a year left until the 22nd World Martial Arts Tournament, John decided to take a break from gravity chamber training for the time being. Instead, he planned to spend some time mastering the art of flying.
John estimated that his current power level was around 1,000, but he felt embarrassed that he couldn't even fly.
As John exited the gravity chamber, Bulma happened to be in the garden, preparing to take off in her plane. She was surprised to see John and exclaimed, "Wow, the sun must be rising in the west! The training maniac is actually taking a break from training!"
John replied, "I have no choice. The gravity chamber you made can only adjust up to ten times Earth's gravity, and I've already fully adapted to it. I've been training like this for two years, and the mental pressure is too much. I need a short break."
"Then, do you want to come with me to Kame House? I'm planning to visit Yamcha," Bulma suggested.
John thought about it and agreed, "Sure, no problem. It's been over two years since I last saw them. It'll be a good opportunity to catch up and see how their training is going."
"By the way, have they been using the gravity control room you made?" John asked as he climbed into the plane.
"Yes, they've been using it for the past two years, and they say their strength has improved a lot. They're looking forward to surprising you and Goku at the next World Martial Arts Tournament," Bulma said happily, pleased that her creation was helping her friends' training.
"Okay, let's go then," John replied, piloting the plane with Bulma towards Kame House.