This is a tried and true classic given to me by one of my military buddies. This core workout is short, sweet, and to the point. You can throw it in however you want to, but it was designed with the end of a workout in mind. I do not recommend this to anyone who is not adept at core workouts. You can seriously injure yourself if you are not prepared and I do not take any responsibility for the actions of others. This is all just advice and you can choose to follow it if you desire.
At the end of every upper body workout, I throw this core workout in that really works my abs. You'll want to include in upper body days instead of leg days and running days. There isn't a significant danger or anything, but when you use your legs, you activate your hip flexors, which get torched in this workout if you do it right. Here is the workout in an itemized list:
1. Find an incline bench and set it to 45 degrees (or it's highest setting) and get an 8 to 12 pound medicine ball. For this part, you need a partner to catch the medicine ball. You start in the up position and hold the ball over your head. Control your movement back all the way down until you are flat on the bench. Then you sit back up with the medicine ball still over head and toss it to your partner. They then toss it back to you and you go back down and come back up. This time, when you are back up, you twist to one side, return the ball over head and go back down, then up, and toss. Every other time you come back up, you toss the medicine ball to your partner. On the times in between, you twist side to side. Every twist counts as one and the workout consists of 10 twist sets. On the first set, you do one twist. On the second set, you do two twists, then three, then four and all the way to ten, making sure you toss and catch the medicine ball in between each twist set. It sounds really complicated, but once you break it down. it's pretty easy to do. This entire exercise is repeated twice.
2. The next core workout is done on an ab crunch machine and is really basic. There are three sets that have subsets in them. First set you do twenty five reps in the normal crunch position. Then you cross your legs at the ankles (right over left) and hook them under the left shin cushion and do twenty five more reps. Last subset you cross your legs (left over right) and hook them under the right shin cushion and do twenty five reps. This completes one set. You repeat the same exercise, but on three different increasing weights. For example, your first set would be done on 50 lbs, then 60lbs, then 70 lbs. You don't want to over do it, but you also don't want to cheat yourself, so make it hard, but don't be stupid.
3. The last workout is basically a V sit with an added bonus. Find a light to medium weight dumbbell and hold with with both hands. Sit in a V sit and touch the dumbbell on the ground on your side and go from side to side. Make sure the dumbbell touches the ground on each side and go to 50 reps. Obviously, you don't want a super high weight, because that will get pretty ridiculous, so be reasonable. Once you have completed the first set, rest for a minute or so, then repeat it two more times with or without a rest in between. If you want to make it harder, up the weight slightly each time you do a set.
That sums up my micro core workout. Do not go overboard with it. Every muscle group needs rest to repair. Stay tuned for more workouts! I come up with new ones every week...