I read a research yesterday done on 30 athletes, all were challenged in a rowing competition where they performed alone. 15 were told they performed beyond average and 15 were told they underperformed.
The athletes who were told they were better than average had an average testosterone increase of 7.3% while the athletes who were told they didn’t do well show a testosterone level drop of 10-15%.
That’s the importance of positive reinforcement. You need to feel like a winner to be a winner.