Whether your riding the 50 mile or 100 mile GFNY course your training should be a marathon, not a sprint. You should start training in December but start slow. If you start training all out you’ll increase your chance of injury and you’ll be mentally be burned out by May.
I’d start your training by attending as many GFNY training rides as possible to build up your endurance and familiarize yourself with the course. You’ll also meet a great group of people to help motivate you during your training.
You may be able to finish GFNY just from just the training rides. Though if you want to finish strong, before the end of race car and be able to walk the next morning you need to do some trainining on your own. I would shoot for 2-3 days of riding a week in December and January. In February add a day, riding 3-4 days a week. A few of those extra training days should be structured workouts. I recommend an Elite Trainer for your indoor structured workouts.
I’ll provide more details on setting up a training plan and training indoors in a future blog.