Blog reader DanO sent me an email with a question regarding running off the bike in training:
I just read this thread on slowtwitch and I was curious why you said what you did. Is it your belief that it is not effective to run after biking in training? Only at certain times in a training cycle? Never? I always thought it was part of the sport specificity in triathlon training. I'm interested to hear your thoughts.
Here's my reply:
Running off the bike is specific to triathlon, it's just that running off the bike all the time is not specific. Running off the bike is not different from pure running, and there is even evidence to prove this. So in order to have a good running performance in triathlon, the main goal is to build fitness on the run. If you are running off the bike too much in training, you will take away some quality from your running training, thus preventing you to build your running fitness.
Certainly running off the bike is a skill that needs to be worked on, especially for those just starting the sport. But for the more experienced athletes, it is less important and running off the bike should be done maybe one time during the week. The exception to this is for time-constrained athletes or for ITU racing. In ITU racing, athletes run their fastest pace of the whole run right out of T2 and at the end. So learning to transition to run your fastest pace right off the bike is important. But again, this can be trained by doing specific workouts, not by running off the bike all the time.
As a general comment, I will remind you that specificity, as with the other training principles, is a pretty complex concept. It does not mean that training should emulate racing, it means training should reflect the needs and skills required by racing.