Training should never be easy, but for those who strive indoors and outdoors there is often a common observation: indoor training is harder and invariably requires greater commitment and greater energy production.
The question is: why?
One of the main factors contributing to increased perceived exertion indoors and outdoors is heat. However, wind speed, body position, and attention also play a role in creating unique differences between indoor and outdoor exercise performance.
First, though, let’s look at the benefits of indoor training.
Why we train indoors
Most cyclists complete indoor and outdoor training sessions throughout a season. The decision to train indoors or outdoors may depend on the weather or personal preference.
Related: The Best Indoor Workout Apps
Even in the best conditions, indoor cycling creates a better environment for the most intense effort without fear of losing focus on handling the bike or your surroundings. Anyone who has tried to complete an outdoor FTP Review will know how tricky it can be to find a stretch of road where you can actually empty the tank without inhibiting traffic, undulations and technical corners where the gas
Add to that the endless variables surrounding outdoor training and sensors: power meters are affected by atmospheric pressure and outdoor temperature, which can reduce their fidelity. Inside, controllables can be easily controlled.
However, the fact that indoor training can be much more difficult is also a reflection of the fact that conditions are often far from optimal.
So let’s look at why indoor training is more difficult and how we mitigate the effects.
A major factor that makes indoor training more demanding is wind speed. When training indoors, it’s a good idea to install a fan or two that can replicate the constant air circulation that occurs when you’re riding on the road.
However, no matter how good your indoor training setup is, artificial air circulation is ultimately inferior to the wind created by a moving bike and prevailing weather conditions.
Read more: How do pro riders use Zwift in the off-season?
Natural air circulation surrounds the entire body and has been shown to reduce skin temperature more effectively than similar conditions in a laboratory. Male cyclists riding at 60% VO2max for 1 hour in the wind (outdoors) have been reported to have skin temperatures that were reduced by 0.68 degrees compared to indoor testing.
Indoors, convective cooling is lower and can cause an increase in sweat rate which creates some dehydration and subsequent cardiac drift (a higher heart rate). All this causes sensations of greater effort when driving indoors.
One of the most overlooked factors in higher perceived exertion indoors is body position.
When riding outdoors, a cyclist is constantly making micro-adjustments to their position on the bike. The course’s undulations, short or long climbs followed by fast, winding descents require balance and a well-developed sense of proprioception.
Proprioception is knowing where the arms, legs and torso are in three-dimensional space. The world champions of proprioception are cats. In the unlikely event that a cat falls from a fence or tree, it will always land on its feet. For cyclists, proprioceptive skills are more rudimentary compared to cats, but we use our neural network in the same way to maintain balance every second of an outdoor ride. However, inside it is a different story.
Here we are locked into a narrower range of body positions. The options are to ride on the hoods or go down to the drops. This restricted range of motion leads to a faster onset of fatigue in the motor and postural muscles because the same muscle fibers are subjected to a constant load. Outside, it’s easier to spread that load across a wider muscle mass, while the bike’s lateral movements create leverage that can also aid forward propulsion.
Attention is also an important factor in the perception of difficulty within an indoor training session.
Psychological awareness of physical exertion is commonly measured with the Borg RPE score. This is a 6-20 scale that correlates well with physiological measures of heart rate, power output, and blood lactate levels.
Tammen’s Focus of Attention Scale has also been used in research to examine cyclists’ focus during indoor and outdoor exercise. It is a 10-point scale ranging from 0 (complete dissociation) to 10 (complete association).
Dissociative thoughts are a disconnection from the task at hand and for cyclists include daydreaming, observing the environment or listening to music. Associative thoughts include paying close attention to breathing, pedaling technique, or the head unit of the power meter.
Research using Tammen’s attentional focus scale has found mixed results as to whether associative or dissociative thoughts are best for performance. However, there appears to be a higher tendency for associative thinking during indoor cycling.
This increased awareness of the environment or the details of the training session can lead to a greater sense of perceived exertion (RPE) when riding indoors. It’s also one of the reasons online cycling platforms are so attractive, because they encourage dissociative thoughts that lead to feelings of inferior effort.
The +/-20 watt rule
It’s a well-known rule of thumb in training circles that for any indoor training session, you should subtract +/-20 watts from your outdoor training goals.
This number was not conjured up by some mystical combined wisdom of the global coaching community. Instead, there is very good research that indicates that +/-20w is a solid starting point for setting your indoor training zones.
The golden thread that runs through this field of research is that most riders are able to produce more power in the open air than inside the lab with a minimum increase of 11% and some of that. being 70%. In terms of power, reports have shown that after a series of repeated 40km tests, competitive cyclists can produce from 11w to 23w more when train out.
Tips to make indoor cycling easier:
So, if you find indoor cycling a bit more difficult than riding on the road, you’re not imagining it. Indoor cycling is more difficult. But if you follow these tips, you’ll be fully equipped to make your next indoor session more productive and much more enjoyable.
- Accept that training indoors is hot, but understand that there are ways to help with training in the heat.
- Make sure you have good air flow in your training room.
- Pay close attention to your body position. Try moving in the chair after each set of intervals, or alternate from hoods to drops every five minutes. Changes in cadence can also help redistribute the load across a larger range of muscle fibers.
- Set up your training room for dissociative thinking. This can be accomplished by watching a movie, a group trip to your favorite online workout app, or by playing music.
- The +/-20 Watt Rule: Take 20 watts out of your outdoor training areas. For some intense intervals, you may need to subtract more than 20w.