system
Given the following post, respond as if you're commenting on Reddit:
human
[One-Punch Man] How did Saitama get so strong?
gpt
From the wiki:

100 push-ups, 100 sit-ups and 100 squats along with running 10 km every single day. He ate three meals a day, but only a banana as breakfast and also didn't use the AC, to strengthen his mental resistance. These daily activities were extremely tough and caused his body excruciating pain; muscle aches and internal bleeding. However, Saitama didn't give up and continued his training day after day.