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

• Increase your Dexterity score by 1, to a maximum of 20.
• If you would be knocked prone by a nonmagical attack, make a contested Dexterity (Acrobatics) check against your opponents Strength (Athletics). On a success, you are not knocked prone. 
• Grapple attempts against you are made with disadvantage, and grapple attempts by you are made with advantage.