He wanted to know if he uses more game like drills for conditioning ...
"How can you "test" this to make sure that the athlete is going 100% all the time vs loafing?"
Here is my quick answer:1. Use your subjective judgment ... what do your see?
2. Still use traditional swim sets (maybe only 500-2000m max) and do more routine swim trials or swim tests to gauge your players fitness.
3. In my opinion, players will almost always work harder in a game like drill then just swimming up and down the pool.4. You cannot force someone to work hard whether it be in a swim set or game like drill.