Resizing is always optimal after every bet, but it's not necessarily practical. You probably should become familiar with the Kelly Criterion, although betting full Kelly will probably cause you a few grey hairs. For example, if you have an 80% chance of winning a even money bet, you'd bet 60% of your bankroll on it to maximize growth.
If my math's right, I think you'd bet 93.75% of your bankroll, for full kelly.
Edge/variance * bankroll = wager
Edge is 0.60
Variance is 0.64