Training theory is rapidly evolving. What we know today dwarves what we knew 20 years ago! Understanding the history of training is an undeniable advantage. In the 1950's, Roger Bannister ran incredibly little while doing a massive amount of intense speed work. That approach was flipped on its head in the 1970's as American runners focused on lower intensity but very high mileage running.
Two years ago, when I discovered there wasn't a Guinness World Record for the longest time spent playing a trumpet, something clicked. I emailed Guinness and applied to be a record-breaker. At first, I was terrified. The rules alone were overwhelming: I couldn't repeat a song, so I needed a very long set list. Improvisation wasn't allowed — no soloing or jamming, only strict melodies. I could only take a five-minute break each hour, but I decided to play nonstop for hours to accumulate a longer break.