Most people will say that the extra time is better spent on more swimming, biking, and running, and for many people this is probably true. However, there are other good reasons to do some strength training, like resilience/injury prevention and
(in older athletes
) preventing loss of muscle mass and bone density.
If you were to choose one area to work on, it would probably be core strength for most people. It is needed for all phases of the race
(holding proper body position and generating stroke power on the swim, holding aero on the bike, efficient run stride
) and isn't specifically developed in most tri training
(except maybe the swim, if you're doing it right, and especially if you're using a variety of strokes
). Doing some core exercises should not seriously impact your fatigue levels for swim, run, and bike training, unlike strength workouts using the arm and leg muscles.
Swimming is really technique-heavy, and strength is not a limiter for most triathletes' performance on that leg. My understanding is that leg strength is also not typically a limiter for most people, except maybe for smaller, lightweight women
(i.e. people like me--I do do some cycling specific leg strength exercises in the off-season
) on the bike. And if you look at elite distance runners, clearly many have not spent much, if any, time in the weight room, except maybe for injury prevention or rehab purposes. That being said, both biking and running work the glutes heavily, and they are tight and weak in many people, especially those who come to tri with a run background and/or sit for much of the work day. So if you had extra time in addition to doing some core work, I would work on glute strength and glute/hamstring flexibility. A 15-30 minute routine three times a week should be plenty. Probably the biggest bang for your buck.
Edited by Hot Runner 2018-07-19 8:46 AM