This is was 800m training hurts and only a few athletes over 40 can run 2 mins or better. This was a session we used leading up to a major event. A very hard session meant to test the athlete mentally and physically. A very good lactic session to build tolerance. Unfortunately in this case the athlete run way under target times and destroyed himself. My mistake as a coach. I gave hime this session to close to competition. He didn’t recover from it and went into the comp very flat. He ran a faster time in comp a few weeks earlier. A good lesson learned.