Rain Vs Pain Vs Gain

Sweating it out on the turbo is unavoidable over winter, but how do the fitness benefits compare to riding outdoors? Must you battle the elements to stay at your best? Jim Cotton investigates

How are you feeling at the prospect of dusting off your turbo trainer and spending less time on your local training roads this winter? Even the biggest fan of indoor training must admit it’s just not the same as riding outdoors. Yes, the apps and smart trainers available these days are awesome, but it always feels that bit harder, physically and mentally, when stuck inside. What exactly is the difference, in terms of gaining and maintaining fitness? We decided to find out.

Have you ever wondered why your heart rate goes through the roof and power tails off quicker indoors? Partly this is because the physics are different: riding on a turbo trainer demands us to move a flywheel — a weighted disc — rather than an actual wheel on a road surface. The turbo’s flywheel is designed to replicate the forces that we generate while riding outside. However, it’s impossible to exactly mimic that propulsive force or the tiny fluctuations in gradient and surface outside — and that leads to a slightly different load on our legs.

Ciaran O’Grady is a Team Dimension Data coach who is working towards a PhD in human performance, focussing on data collected from turbo trainers.

“The lack of true momentum and inertial changes that you would produce outdoors means there’s biomechanical differences when you ride inside,” he explains. “You have to generate a different type of inertial load on a turbo trainer, and that changes your pedal stroke. You become a lot more quad-dominant on the trainer, whereas on the road you use a more balanced combination of quad, hamstring, calf and glute.”