a. For time:
Bike 50 calories
Sled push 50m (80/50)
Run 1k (backwards)
-Take off/start in pairs early on. Have the sleds already loaded and ready, the sled push is one way (50m out) your buddies will re-set / bring those sleds back for the next pair. The backwards run is nothing new, just uncommon. It's good for teaching you to stay on the toes while running ie. Good technique. As well as challenging your balance and awareness.
Use the driveway (5 laps @ 200m) if you're a bit weary of obstacles or take on the 1k loop.
Scale: Lighten the load of the sled and / or reduce the run distance to 600m
-Do this in your spare time at some stage within the session.