Multisport Training Protocols

Hi all,
Just wondering what the state of the art recommendations are for developing general endurance across a number of sports. I presume it still:

  1. Develop an L2 Base across any sport. Aim for 2-4 hours (or longer) training sessions.
    2.Let your body adapt to specific event requirements. If you are biking 100 miles then you’re sitting in place so some L2 should focus on that. If you are kayaking for 50 miles same deal.
  2. V02 Intervals are still recommended for shorter workouts.
  3. Add some other intervals for variety cause endurance training isn’t always fun.