A good cross training strength program is an important part of racing better in triathlon. But Crossfit may not be the best place to get what you need. Each Crossfit Box (that's what they call their gyms) is a bit different and some offer programs specifically geared towards endurance athletes looking to incorporate some Crossfit style workouts into their programs but their primary focus is not Crossfit. Our Box in Hood River offers these and I think they work well for some people. I would not recommend the generic WOD, workout of the day. As other people have mentioned above, those workouts make you better at Crossfit, not triathlon, and the injury rate is fairly high in the general Crossfit population. Something like 16% of new people to Crossfit sustain an injury (please realize I don't know how the research defined "injury") within the first several months of participating. So you have to be careful, self monitor well and be willing to put your competitive self aside to practice Crossfit safely.

I had a successful AG triathlete as a patient who went to CrossFit. She was familiar with it but hadn't been for several months. Her first day back she got overly competitive and did a ton of box jumps. Partially tore a muscle in her buttock and it was about 3 months before she could run again. Injuries happen in every sport but the highly competitive environment at Crossfit seems to lead to problems for many people.