There are many ultra runners that do triathlons for variety in their lives, and many triathletes that run ultras for the same reason.
Understandably, you will not find an online program that builds switching from ultra to tri and back – you will need to work with your coach for that. One thing that I have picked up is the trend line of cardio fitness levels that matches what is needed for various ultra distances to a corresponding triathlon distance.
What have your experiences been as an ultra / tri crossover athlete? Share below.