Increase one of your base stats (ie. Strength, Endurance, or Agility) to have a value of 50 or more.
This is hard to track due everytime you change your powerup ability the stats change. My recommendation is to just keep leveling up your Endurance, this way you will stay alive long enough to keep leveling up and hopefully keep your run for Juggernaut (Complete the game without dying) alive.
I didn't use every point on my endurance but I did focus mainly on it, the achievement popped after appling my stats to level 9.