Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used. Jeffrey Kluger
Willpower is the key to success. Successful people strive no matter what they feel by applying their will to overcome apathy, doubt or fear. Dan Millman
With but few exceptions, it is always the underdog who wins through sheer willpower. Johnny Weissmuller
I get Tweets every day from people telling me that 'Hey, I'm going to overcome my injury or my illness. Cancer. Different diseases. I can beat it because Adrian Peterson showed me the determination and the willpower to be able to prosper and get through adversity whenever it comes.' Adrian Peterson
When people have a willpower failure, it's because they haven't anticipated a situation that's going to come along. Charles Duhigg