Here's what the beginner 5 minute ab workout looks like:
Plank (1 minute)
This is a great warm-up to engage all the muscles in your core. If you're not accustomed to planking and feel like you're losing your posture (butt going up in the air or back starts sagging) drop to your knees.
Scissor Kick (30 seconds)
Roll over on your back, hands by your sides or under your butt and start kicking your legs back and forth. Keep them as straight as possible and never let them hit the ground.
Figure 8 (30 seconds)
Stay on your back, keep your feet together, hover them above the ground, and start making a figure 8 with your legs and feet. The key is to keep your butt glued to the ground.
Plank (30 seconds)
Side Plank (15 seconds each side)
From your plank position, roll to one side and keep your weight on one forearm and stack your feet. Keep your hips from sagging and you'll feel it in your obliques.
Briefcases (15 reps)
Start out in low boat and lift your chest and knees until they meet each other. Keep your arms straight and begin wrapping them around your legs as you lift up, without holding on to your legs. Lower yourself back down without your upper back or feet hitting the ground...that's one. If you've done Ab Ripper X (part of P90X), Tony Horton refers to these as crunchy frogs. To make it harder, do as many as you can in 30 seconds.
Leg Up Pelvic Thrusts (15 reps)
Lay on your back, feet together, lift them straight up to the sky and then pulse up so your pelvis hops of the ground. Lower your feet down without hitting the ground...that's one. Make it harder and do as many, controlled, as you can in 30 seconds.
Plank (30 seconds)
Mountain Climbers (30 seconds)
These can be done from your plank position or high push up position. I prefer going straight from plank into mountain climbers. Bring your left knee to your left side and touch your elbow with your knee, if you can, and then set your foot back down by your right foot. Repeat that motion on your right side and continue to alternate that same motion for 30 seconds.
That's it; you just got a great core workout in 5 minutes! Next time a commercial comes on or there's a timeout during the game, bypass the trip to the pantry/refrigerator and get a solid core workout.