I’ve had my forerunner 955 watch now since January and in that time I’ve worn it for almost every run. In training I regularly run 100+ miles a week and have been focusing on getting my 10k time down from 29:20. Recently I just ran a 10k in under 29 minutes. In training for this I regularly do tempos, double threshold workouts and intervals faster than race pace. My VO2 max on the watch does seem a little low at 67 given the times I’ve ran, but the race predictor is extremely inaccurate. For 10k the predicted time on my watch is 36:30, which is extremely far off the sub 29 10k I recently ran. They are on two different levels!