Ultramarathoner

Through relentless training for extremely long-distance running, you have unlocked a nearly superhuman level of endurance. Your abilty not only to shut off pain and shrug off tiredness, but also to have the time of your life while doing so, makes you the envy of your fellow adventurers, although few of them would be willing to travel the ungodly distances you do for the purpose of "having fun." You gain the following benefits:

• Your Constitution score increases by 1, and your maximum for this score is now 22.
• You have advantage on saving throws to resist becoming exhausted.
• When an effect would cause you to automatically gain levels of exhaustion, such as the berserker's Frenzy feature, you can make a DC 20 Constitution saving throw. On a success, you avoid suffering any exhaustion.