As a bonus, here are three exercises triathletes (or any athlete for that matter) should never do again:

Crunches - The movement of crunching puts the spine into flexion. The spine does not want this load. The function of the spine is meant to remain stable. Repetitive movement at the lower spine will cause pain or even worse a blown disc. Read any of Dr. Stuart Mcgill’s, a low back specialist, research and you will see why spinal flexion, extension and rotation are a recipe for a blown low back disc. Want a healthy and strong back? Build stability and stiffness and stay away from crunching.

Leg Curl Machine – This machine is a very non-functional “strength training” exercise. First of all it is a machine. Machines do not build function. Your movement is constricted on an exercise machine. Secondly, this exercise will work the hamstrings without engaging the hips and the glutes. When you do that it will lead to over dominant hamstrings, thus leading to imbalanced glutes and hips, which can lead to injury. These two muscle groups need to work together. Try the stability ball leg curl instead. This will allow your hips to work with your hamstrings and this will create balance and a strong posterior lower body.

Low Back Hyperextension – Have you ever done the “Superman” exercise? Just like crunching this is another recipe for low back pain. Again the low spine is meant to remain stable. When you put unwanted load on the spine it will cause serious back issues. It might not happen the 1st, 3rd or 50th time you perform this exercise but every time you perform spinal flexion, extension or rotation you are setting yourself up for disaster. Stay away from this exercise.

Resources:
Mike Boyle, “A Joint by Joint Approach”, www.strengthcoach.com
Mark Verstegen, “Core Performance”, www.coreperformance.com
Dewey Nielsen, Impact Performance Training, www.impact-pt.com
Triathlete Magazine