Sit Ups.php

Your abs are important in so many ways: one way or the other, they're involved in almost any activity that doesn't isolate a specific muscle group. In other words: you ride your bike, you use you abs. You row, you use your abs. You run, you use your abs. You run an obstacle race, you use your abs big time: jumping, crawling, climbing, lifting and carrying heavy objects, running, etc. Come finish time, your abs will know what you've put them through!

So...it only makes sense to make 'm strong. Strong abs allow you to run more efficiently, lift and carry with better technique (and help prevent back injuries!), crawl faster and climb smoother.

So many options
There are a lot of ways to strengthen your abs. For now, we're just going to focus on the basic sit up though. We're going for a full range of motion, so no crunches. Crunches definitely have their place in a workout regime - especially if for some reason you can't do sit ups (yet) - but an obstacle race hardly ever calls for an isolated muscle contraction, so we need to prepare for that in training.

The basic sit up
Lie down and pull up your knees so your legs make a 90 degree angle, keeping your feet on the ground. Now place your hands near your ears (entangling your fingers behind your head is an option, but be sure never to pull your head), and raise your upper body, using your hips as the pivoting point. After reaching your highest point, lie back down on the floor in a controlled manner (so don't just relax your muscles and drop your upper body). Repeat.

How to (not) mess up your sit ups
Keep your back straight. Don't jerk your head up. Don't clench your fists, as this will probably lead you to create some sort of incorrect momentum in the upward movement, whereas a sit up is supposed to train your abs, hips and back muscles - not your arms or shoulders.

Don't let your upper body get in front of your hips. As a matter of fact, it shouldn't even get above your hips. At its highest point, your upper body should still be leaning back - albeit slightly. Don't fixate your feet (nor allow someone else to hold them down for you), as this will basically reduce your sit up to a hip flexor exercise.

Your back is sacred
If there's one exercise you never want to perform without proper control, it's the sit up. Sure, your muscles will (and should!) feel the burn. But you must discipline yourself not to drag / pull / whatever your upper body off the ground when your abs are starting to have a hard time. Keep focusing on your abs and the other muscles involved will follow. Lose the abs, lose your form, hurt your back - it's that simple.

Crunches
And that's where crunches come in: if your abs are a serious bottle neck in your sit ups, you may want to add some crunches to the mix (or just stick to crunches until you've built up enough ab strength to switch to sit ups). The difference between a sit up and a crunch is that with a sit up, your whole upper body comes off the ground and with a crunch, it's just your head and shoulders. So if you're looking for a way to strengthen your abs without running the risk of hurting your back, do crunches.

That is not to say sit ups will hurt your back. Sit ups are awesome, as long as proper form is maintained. Injuries don't stem from exercies. Injuries stem from ill performance.

Other ab exercices
Flutter Kicks
Hanging Leg Raises
Leg Raises
Medicine Ball Sit Ups
Russian Twists
Scissor Kicks