You have undergone extensive physical training to gain the following benefits:

• Increase your Strength or Dexterity by 1, to a maximum of 20. (Athlete Feat)
• Your climbing speed is increased by 10 feet. (Half that of Tabaxi's Cat's Claws ability)
• When attempting to climb an unstable surface you may use your Acrobatics skill rather than Athletics. (Is this too strong?) (Maybe Athletics with DEX rather than STR?)   
• While climbing you produce little to no sound and may take the hide action and remain hidden at no penalty.