I tried my first 'cross event last year and barely made it around one lap. Falling and mashing my hip and the first run-up didn't help matters, but mostly I ran out of gas. The intensity of going from stop to all-out and maintaining it was unlike any riding I normally do.

I'm looking for a few actionable (useful and practical for someone who works full time all week and then has family responsibilities) steps to take to increase my endurance so I don't run out of gas on the first lap. I have no delusions about being competitive, just want to stay on the course and have fun.

Should I, for example, limit my longer club rides and focus on going all out for a defined period of time? Should I hit the running track a couple of nights to build endurance on foot?

I know volumes are written about this and I'm not looking for a CTS consultation, just some practical tips that have served you well.