Creatine is not generally recommended for aerobic athletes although there is some new research around using it for glycogen replenishment, recovery and favorable substrate utilization (less reliance on glycogen at certain crossover junctions in energy systems.) Therefore if you’re thinking about using it, you should experiment in the off-season. Obviously you don’t want to gain weight so make sure you monitor properly. If you chose to use, I would still use the 5g/day only because it takes a while to load at this dose for anyone. After 1 month, you could probably drop to 3g/day.