I recently purchased an Elite Direto XR smart trainer to which I attached my old Specialized Roubaix road bike. The results have been fabulous and provide a useful alternative to road riding when the weather is foul or injuries keep you off a regular bike. There are many types of trainers on the market ranging from roller type trainers which involve you placing your bike on rollers to simulate being on the road through to devices that allow you to attach your bike's rear wheel onto a hub that can be set to provide various levels of resistance and right up to smart trainers that can connect to apps like FulGaz or Swift so that the app controls the ride based on the terrain being ridden across as seen on a computer or TV screen.
The Direto XR comes with a Shimano Ultegra rear cassette so you simply remove your rear wheel from the trainer bike and connect the bike to the cassette via the rear derailleur. You then power up the Direto and make a blue tooth connection to your App of choice (FulGaz in my case - see review in Bikes and Accessories) and get ready to ride. In some ways its just like being on the road, while in others its a whole lot tougher. You select your ride route having regard to trip length and the amount of climbing and start pedalling. You are inside so no wind, rain or swooping magpies, but on the down side, there is no wind so it can get very hot, you don't get to coast along on flat or downhill stretches which can be tiring and boy does the seat start to feel hard the longer you ride.
With a smart trainer you can use your gears and you find yourself constantly referring to your bike computer as depicted on the screen so that you can see when climbs are coming and ensure you are in an appropriate gear. The smart trainer will probably allow you to set resistance rates so that climbs are manageable. As an e-road bike rider I have become used to climbing with some assistance, so I have set my Direto so that the gradients being attempted are effectively halved. That is when the app says its a 15% climb, my smart trainer sets the resistance to about 7% meaning that I can still pedal without having to stress my knees. However, even with this change I have struggled from time to time with some rides set in Germany and Italy having gradients of 23%.
About the time I received my Direto I was involved in a slowish, head on bike to bike crash (other rider on the wrong side of the path) and I was able to get on the trainer after a few days of recovery. The Direto was instrumental in helping with a quick recovery and getting me to a level of fitness I hadn't experienced in many years. Each day I was riding 30-50 kms in countries all round the world using actually recorded rides that had been converted into rides available from my app, including the Olympic Time Trial route from the recent Tokyo Olympics, a ride along Ocean Road in Melbourne, and rides throughout Germany, France, Italy, Scotland, ect, To top it off I discovered that a rider had recorded a route that combined several rides I often do around my home city of Canberra and I was able to complete a 53km ride that was very familiar and dealt with my feelings of sadness at not being able to get out on the road.
I would therefore highly recommend using a trainer bike as a way to maintain or improve fitness and a way to see the world fro a bike. Today its late spring in Canberra, but as with the whole south east of Australia, its raining and expected to get worse. So it was great to get on my trainer and do a 45km ride round a bike path loop in Dubai. The route was interesting - a single 45km loop on a bike path which looked like a new road made of bitumen and with road markings dividing the path into a two way path. The only downside was it was flat with only 100m of climbing and the scenery was sand, an occasional tree and cars on the adjacent road plus the occasional rest stop consisting of a tent like roof covering bench seats and bike racks. These facilities lloked good, but while I saw lots of cyclists riding in the opposite directions, the rest stops were all empty. Perhaps it was too hot to stop?