Day 21 - Corn Cob Pull-ups

Difficulty - Advanced
Muscle Groups Addressed - Delts, Lats, Pecs, Biceps, Back

Had to throw another P90X favorite your way. The corn cob pullup is a juiced up version of the timeless classic. Before we dive in, perhaps a little basics tutorial on the multiple variations of grips you can use for a pull-up. Based on your grip, you can target multiple different muscle groups and adjust the intensity of the exercise.

Supinated (palms up) grip = Chin-up (more biceps, easier)

• Chin-up with narrow grip - 4-6 inches apart; engages forearms more
• Chin-up with neutral grip - ~12 inches apart; overloads elbows, heavy use of biceps
• Chin-up with wide grip - 12-24 inches apart; engages

Pronated (palms down) grip = Pull-up (more back, harder)

• Pull-up with narrow grip - Emphasizes lower lats and works biceps due to ineffective angle
• Pull-up with neutral grip - Overloads forearms and shoulder stabilizers, heavy use of the back
• Pull-up with wide grip - Emphasizes upper lats and upper pectorals

If you're not at the stage where you can do a full pull-up, put a chair underneath and support yourself with one or both feet.

Just make sure no matter which variation you're performing, you come all the way to the bottom and fully extend your arms. If you don't, you're not getting the most out of the exercise and you're neglecting all your synergist and dynamic stabilizer muscle groups. Also, try not to "kip", or use a jerking motion (momentum) to get yourself over the bar. Nice, slow, controlled movements will maximize the benefit of this exercise.

For corn-cobs, choose your grip and hang down with your arms fully extended. Slowly raise yourself up until your head is over the bar. Once you reach the top, in an isometric hold, shift your body to the left, then shift your body to the right, then come back to the center. Now, slowly release and lower your body down to a full hanging position. Repeat as many reps as you can. Again, the home/work version is exactly the same, you just have to find a doorframe or a pipe to hang from (careful to make sure it's not a heated pipe...)

Day 3 - Isometric Bicep Curls

Difficulty - Easy
Muscle Groups Addressed - Biceps

Isometric exercises do not require concentric (shortening) or eccentric (lengthening) muscle movements. In other words, recall the last time you were forcefully tugging on a wine cork and it wouldn't budge... or trying to force off a stubborn lug nut while changing a car tire. These were exertions of force that did not contract your muscles either way, but instead worked them while in a static position. This makes them particularly effective in our mission for incidental wellness, because you can generate static force against any and all immovable surfaces you find out in the world.

For the gym variation, a preacher curl bench is the best way to ensure proper form. Otherwise, just stand up straight with one foot slightly in front of the other for balance. Starting at a lowered position, one arm at a time, bring a moderate weight (50%-75% of your traditional 8-repetition bicep curl -- if you don't know what your "usual" is, go find out!) up to where your bicep and forearm form a 90 degree angle. Hold this position for 30 seconds. Switch arms and repeat. Keep your upper body and legs relaxed. If you have an exercise buddy, a fun spin is to have them grab a towel, drape it from your open palm, and then apply resistance with the towel as you keep your arm locked in its isometric position.

<-- At work or at home, this exercise can be easily performed by applying upward pressure against the underside of your desk. Make sure to check for gum before you do.

--> Another fun variation involves getting a little undressed. Sit on the floor in a hamstring stretch position, with one foot tucked into the inner thigh of the other leg (shown to the right). Create a loop out of your belt and strap one end around your extended foot. Plant the elbow of your arm against your quad and pull the belt towards you, creating an isometric bicep curl. This variation is great because you'll also engage and stretch the hamstring that's providing counter-force for your curl.