I think MC is overconfident about exactly what his body can handle even with the awakening and everything. It's been what, less than two months since he entered the tower? Three at most since he awakened? And it's not like he could practice in the outside world -it's not a dungeon world, and the tower isn't public knowledge.
The Galactic Navy Officer Becomes an Adventurer
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM