Indoor cycling is no longer a second-rate alternative to riding outside; it’s become a full-fledged cycling discipline on its own, and a primary method of cycling training for athletes who participate in both indoor and outdoor events. With cutting-edge technology available from numerous indoor cycling apps and a wide range of smart trainers and smart bikes, indoor cycling is an appealing year-round option. As more cyclists spend more hours riding indoors, it’s important to avoid some key errors that can hurt performance and limit your enjoyment of cycling.
Overheating is perhaps the most common and most detrimental mistake athletes make with indoor cycling. At best, cyclists are about 20-25% efficient, meaning 20-25% of the energy you expend is used for propulsion and a whopping 75-80% is lost as heat. Much of that heat must be dissipated so your core temperature doesn’t rise to dangerous levels. To keep core temperature within a relatively narrow range (97 – 101 degrees Fahrenheit), your body has five mechanisms for dissipating heat: evaporation, conduction, radiation, convection, and respiration. They are all affected by environmental factors, the most important of which is a temperature gradient.
Heat moves from an area of higher temperature to an area of lower temperature, and the transfer of heat works best with big temperature gradients, like hot skin to cold air. When you are cycling outdoors there is airflow over your entire body. This facilitates convective cooling and evaporative cooling as sweat evaporates off your skin, as well as conduction as warm sweat is carried away from your body by moisture-wicking fabric. When ambient temperatures are below body temperature, you radiate heat effectively, too.
Indoor cycling presents challenges for heat management because it is difficult to fully replicate the airflow you achieve outdoors, which means convective and evaporative cooling are less effective. And with insufficient airflow you can heat the air immediately surrounding your body, reducing the temperature gradient even further.
Why does all of this matter? Well, that pool of sweat under your indoor trainer is really a lost opportunity. It would have dissipated much more heat by evaporating off your skin rather than dripping onto the floor. Higher sweat rates contribute to faster dehydration, which reduces power output and performance. And as skin and core temperature rise, thermal strain increases, which shortens time to exhaustion and reduces an athlete’s motivation to continue training.
The primary solution to overheating is obvious: fans. One is good, two are better, and you’ll love it with three. Aim one at your head; cooling your face plays a big role in reducing perception of thermal strain. Aim one for broad coverage of your torso, and if you have a third aim it at your back. You can also set up your trainer in a cooler environment, like the garage or basement, rather than a heated room within your home.
Whether it is pre-programmed interval workouts on a smart trainer, e-races available around the clock on virtual cycling apps, or virtual group rides that often exceed the pre-determined pace (by watts/kilogram), there are many appealing ways to ride indoors at high intensity. But indoors or outdoors, the majority of endurance training should be completed at low to moderate intensity levels, with only a small percentage of training time devoted to purposeful, high-intensity efforts. Although training needs to be personalized to each athlete’s goals and physiology, one popular protocol recommends an 80/20 percent split between easy aerobic endurance intensity and hard interval intensities.
When athletes get sucked into riding hard every time they get on the bike, the end result over the span of weeks and months is that their training is neither easy enough to maximize aerobic endurance nor hard enough to develop speed and power for events. They accumulate a lot of fatigue, but fitness and performance plateau somewhere in the middle.
The solution is to track your training, either through data analysis software like TrainingPeaks or an old-school paper training log. Be sure to record subjective feedback on individual rides and workouts, too. How you feel provides important context to the numbers in your training data. As you track your training – either with the help of a USA Cycling Coach or one your own – patterns will emerge, and you’ll be able to see and adjust the distribution of intensity across your training.
Training indoors without structure is a contributing factor for riding too hard too often. To train effectively, each ride should have a specific objective – whether that’s a hard interval set, a steady aerobic pace, or just “go have fun”. The 24-hour availability of virtual group rides, group workouts, and e-races on indoor cycling apps encourages some athletes to jump into group activities any time they get on the trainer.
On one hand, if the social aspect of group activities gets you on the bike more frequently or creates accountability to keep you training, then it might be better for you than a structured training plan you don’t stick to. But if you are working toward a goal event or trying to maximize your performance on the bike, following a structured training plan is essential because it schedules appropriate amounts of work and rest, necessary time-at-intensity within specific training zones, as well as the duration of recovery time between bouts of intensity. “Just riding” or randomly deciding when to go hard or easy will improve fitness and performance for a beginner, but experienced cyclists will see their fitness and performance stagnate or decline.
For the best of both worlds, create a structured plan that incorporates your favorite indoor cycling group activities (like group workouts, e-races, and virtual group rides with USA Cycling partners Fulgaz and VidFitness) alongside solo rides and workouts such that the whole plan addresses your performance and event goals.
