For all but the most intense interval sessions, riding outdoors will always trump the trainer. This is because cycling is about so much more than just mashing the pedals and mindlessly churning out watts.
However for highly focussed intervals it’s hard to beat an indoor trainer. You can control your efforts precisely and ensure you’re hitting exactly the right intensity. There are no distractions, no junctions to interrupt you and no other road users to worry about – you can just put your head down and give it the beans! An indoor trainer is also great for fitting in a short blast on the bike if you’re time pressed or unable to leave the house.
The workouts that you should be getting out and riding for real are your endurance and race simulation rides. Sitting on a turbo watching a boxset or plugged into Zwift for hours on end is no substitute for putting in these miles on the road, and won’t prepare you for a real race situation. Do you race a triathlon indoors? No, so don’t fool yourself into thinking that riding indoors will you prepare you for one! Here are some more reasons why the outdoors will always trump the indoors:
Cornering, descending, eating and drinking on the bike, dealing with the wind and having other riders around you are just some of the key experiences that you can only get from riding outdoors. It genuinely fills me with dread when I hear about triathletes who do all of their winter training indoors and then, come spring, rock up to race. It’s like playing Mario Karts and then having a punt at F1.
I know there are some triathletes who live in climates where indoors is genuinely the only option, but in the UK that’s just not the case. I live in the north of England and, over the last winter, there were probably only a couple of weekends when riding outside wasn’t an option at all. This isn’t a macho boast, I was wrapped head to toe in top end technical kit, but you shouldn’t use the weather as an excuse for not getting your outdoors miles in.
Getting out and riding for real is always more of a mental boost. Chances are you’re stuck indoors most of the day, so for the sake of your sanity, save the turbo for when it’s really necessary and get out there. Hit the road, get some mood enhancing fresh air and, hopefully, a hit of vitamin D to boot.