Athletes finding they lose time in the downhills, around corners and during mounts or dismounts can use mountain biking to improve these bike handling skills. Riding off road is a great way to gain confidence and skills that translate onto the road. Suspension and fat tires on a mountain bike make descending and cornering easier. Learning to ride at higher speeds offroad builds confidence for cornering and descending on the road. There are weight transfer skills that are easy to learn riding on gravel, which translate to better handling on a wet or rough road surface.
Mountain bike shoes are easy to run in, and mountain bike pedals have dual-sided entry, so flying mounts and dismounts are easier to learn on a mountain bike. This is a great way to improve mounts and dismounts at transition.
Draft-legal athletes learning to ride aggressively in the pack, or Ironman athletes trying to take the fastest line through the turns, can use off-road riding to create better road riding skills.