Do... check out the route
Do... check out the route
Distance is only half the battle. A 100-mile ride (or any distance, for that matter) in the flatlands of Cambridgeshire will be a very different experience to a century ride with an endless succession of climbs (and sportive organisers like to make riders suffer) in the Peak District or south Wales.
If you have the chance to recce some of the route then great, but more that likely you’re preparation will involve looking at the route profile provide by the sportive’s organisers.
Consider the profile when choosing an event (and distance) to enter and then use it to guide your training and preparation. If it’s a particularly hilly event and you’re not a great climber, then pencil in a series of hilly training rides into your schedule.
By paying attention to the profile you can also plan how you are going to pace a ride and there shouldn’t be any nasty surprised when yet another of the short, steep climbs that litter the UK appears from behind a bend in the road. You can also use Strava to get a gauge of the severity of the climbs and if you know where the big climbs are on the route, plan your nutrition around that and pace your ride accordingly.