How close to a race should you test your zones. Have an upcoming marathon and I tested my zones in week 15 using talk test (had lasted tested them 6 weeks prior) and my threshold pace jumped from 8:10 to 7:19, I began training with new zones and immediately started noticing some pains and so I scaled back to a threshold pace of 7:40 out of fear of injuring myself so close to my race. Race is on November 21st (10days) struggling to determine if I should retest zones so close to race, race at a pace dictated by the zones I achieved or the ones I have been training in? My Garmin is currently predicting a 3:30:49 race not sure if that is actually reasonable.