Can doing ab workouts help you?

Yes, ab workouts can help you in your training. By doing abs, you're working out your core muscles which can prevent cramps. You'll also become more fit and you'll see that you can go on longer. In your spare time, if you're not able to run that day or even after your run,  do an ab workout. A good workout would be 30 crunches, 25 sit-ups, 30 bicycle crunches, lift your legs 6 inches off the ground for 30 seconds, and bridges for 45 seconds which is holding yourself up on your elbows. Keep doing these and you will see a difference.