Recumbent bikes don't require you to engage your abs.
The recumbent bike is a valuable piece of equipment for cardio exercise. It's useful for cross training to keep your workout fresh and comes in handy if you have a back injury. The way a recumbent bike positions your body takes stress off your back and provides support for it. If you're interested in performing cardio exercise that works your stomach muscles, you're probably wondering if riding the recumbent bike will strengthen your abs.
Won't Target Abs
Bikes in general don't target your tummy, but you're abs will get the least amount of work when you pedal a recumbent bike. With a backrest to support your back, you won't have to engage any core muscles to hold yourself upright. When you use a recumbent bike, the muscles that do work are essentially all in the lower part of your body. Your glute muscles in particular will get a challenging workout on a recumbent.
Recumbents Plus Weak Abs Equal Injury
If you have weak abs, work on strengthening them before you use a recumbent bike. In her article for IDEA Health and Fitness Association, personal trainer and physical therapist Catherine Logan points to weak abs as a contributing factor in hip abductor injury. For those who have suffered such an injury, Logan recommends the recumbent bike only after completing rehab, which includes ab strengthening exercises. The ironic issue is that you need strong back muscles to support your abs and vice versa, but having back problems is a common reason people choose the recumbent bike over a traditional upright stationary bike. If you have weakness in both areas, it's wise to choose a form of cardio exercise that won't cause pain or injury, and work on building ab and back strength separately from your aerobic workout.
Engaging Your Abs
To engage your ab muscles while on a cardio machine, hold your back straight and keep good posture. Pull your stomach in, holding the muscles taut. Don't lean forward or slouch. Hold your shoulders back and your chin up. This is most effective on machines that don't have a backrest for you to lean on. You can give it a shot on the recumbent bike, but you'll have to sit up and away from the backrest. This can make it harder to pedal; also, not using the backrest defeats one purpose of using the recumbent bike.
Effective Ab-Strengthening Exercises
To work on strengthening your abs, include a variety of crunches, such as twisting, seated and push crunches. Do leg raises and situps, too. Alternatively, if working your abs while doing aerobic exercise is priority, look for activities that engage your core. Idaho gym owner Matt Siaperas steers clients toward kick boxing, martial arts and dance exercise classes for challenging cardio workouts that also strengthen the abs.