"Su Yu... I feel like I'm gonna die... Whew..."
In a clearing in the forest, Naruto performed basic movements, but sweat poured off him, his face filled with pain and strain.
A close look would reveal that even light bent slightly as it passed through this space.
This was a gravitational field Su Yu had specially created for Naruto, with gravity ten times its normal strength. Increasing gravity was the most classic way to train the body, and the very reason it was a classic was that it worked.
And Su Yu's "torment" of Naruto did not stop there. He had "thoughtfully" added weights to Naruto's wrists and ankles, and had even prepared a training shirt specially for him-also a weighted version. The combined effects of these weights and the gravity produced results greater than the sum of their parts. Of course, the pain was multiplied right along with them.
It was precisely because of this painful ordeal that Naruto had no attention left to spare for marveling at this miraculous gravitational field.
Under normal circumstances, putting someone who had only just begun training through this would actually do more harm than good. However, people in the Naruto World naturally had relatively strong constitutions, and Naruto's was so powerful it was practically cheating (to be precise, Naruto really did seem to have cheats). Most importantly, Su Yu was right beside him to provide guidance, assistance, and nutritional replenishment, ensuring that Naruto would never cause himself irreversible damage.
As a result, this training was extraordinarily effective. Naruto's constitution improved practically every minute and second. Of course, the other side of that was the considerable pain Naruto himself endured, just like right now...
Su Yu: "Naruto! Training only started ten minutes ago. Do you already want to give up? Is this your