This year marks the 10th year. I have not made a formal count, but conservatively, I spent an average of 12 race days a year consisting of road and track time trials and team events and road hill climbing. For the first few years of the race, I did a mass start race on both road and track to upgrade to Cat4. After that, I quit the mass start race.
Last year, I decided to focus on sprinting. Sprinting is about strength/weight and CdA/power. One faster can accelerate and go while one stronger and lighter is aero. The ballistic nature of sprinting was very tired of my muscles and other systems. I usually get sick. However, getting sick after a hard sprint or watt bike workout is normal for elite sprinters. I was also able to pull muscles/tendons on my buttocks that plagued most of the season. It has now taken one or three years to heal.
Since sprint does not burn many calories, weight control is more difficult, but the equation in the paragraph above does not disappear. However, many sprinters believe that weight gain is okay and that more power/strength leads to weight gain. I am not sure of it and he is in perfect shape, especially when I see Jason Kenny 5 '10 "176 pounds. IMO, Sprinting is much more difficult to body, mind and life than a classic endurance race. Also, simply sprinting was not so much fun. I would be on the track for three hours and get warm-up, including a windup in the mood like jumping and four efforts are probably lasting for two minutes and waiting for my ATP-PC system hanging around the pit.
I succeeded in doing it and improved my 500 meters time at the age we are supposed to slow down. Which BTW, I simply do not buy to state the classical doctrine.
This year, I decided to return to the road time trial and the pursuit that seems to be quite frankly more free to hill climbing. My ass got better and I prefer the durability side of the lace on the pure sprint. And I know how to train for sprint and throw with some sprint work that I think will help in my 2k pursuit. I believe that having more power is probably a game changer for players, except for world tour grand tour racers.
As for fatigue, I found that about six months is a cycle for me. If it started racing in February and started training in October the previous year, training for the track of the World Championship will be very difficult. When the race starts in February, regardless of region or nationality peaking in July, it will be late as it approaches October if the training continues. In 2011, I talked with one of the British coaches about how the British handled the long season. They take a mid-season break and rebuild for the track world.