Both are good to do abs exercises before and after cycling cardio. You can do them at the same time or you can break the workout into two to three days depending on level of intensity, time commitments, and workout fatigue levels.
Ideally, you should do abs exercise before cycling cardio. This will allow the muscles to burn more calories and replenish the glycogen that is used up during the activity. You can do this by cycling at high intensity (greater than your lactate threshold) for 30 minutes or so, followed by lower intensity biking (below your lactate threshold).
You need to do your abs exercise before you exercise the cardio. So after doing both the ab exercises and cardio workout, then you can take a rest for about 30 minutes
Cycling is a low-impact exercise, so it’s better to start your ab exercises a few minutes before starting cardio. However, once you start doing cardio workouts, you’ll want to incorporate abs exercises as well. All in all, it depends on what your goals are and how quickly you can commit to training 30 minutes per day.
In my experience, the best time to do abs exercises before cycling cardio is when you first wake up in the morning or right after your morning workout. When you’re tired, your body wants to rest, but by exercising before cycling cardio, you can give your body a super effective final push just before you head out for a ride.
While abs are exercised both before and after cycling cardio, doing them first is recommended. It will give you more of a workout than if you do it at the end of your cardio session.
A routine before cycling cardio is best for the abs. The reason being riding on a stationary bike deactivates certain muscle groups more than running does, so you need extra work for those muscles which are engaged during cycling.
Abs exercises before cycling help to warm-up and contract the fascia, which improves body alignment and coordination. To avoid damage to your muscles you should complete your abs exercises before cycling. After completing these abs exercises, you can then do cardio or another type of fat burning exercise