Im not a sprinter, but I've learned that sometimes less is more. Intensity is more important than volume in most cases. Sleeping 5-6 hours a night doesn't make you cool or badass, it makes you an idiot. Operating at 70% just to get a few more hours of unproductive work is silly.
Super long training sessions have their place when trying to increase capacity, but my typical workout is about 45-60 minutes when in the gym. Running and cardio sessions are even shorter.