Be your own competition.
If you're into dance, try new routines regularly. If you like to run, try interval training today, running up a hill tomorrow, still cardio the next day. Challenge yourself. Keep it fun, renew your playlist frequently.
Do not ruin your workouts by stuffing yourself with junk. Do not starve yourself either. Slowly introduce healthier meals and eliminate junk. Control your portions, snack on fruits and have one of two cheat meals a week as a treat.
Love the Body you're in
..because when you love yourself you want what's best for you and you're more likely to do good.. eat clean, workout regularly, speak positively to yourself, and just anything that would lead to positive results.