The Difference in MPI’s Between Riding Outside and Using an Indoor Trainer

Hi, this is Saita from LEOMO. This week I’m going to talk about the differences in MPIs (Motion Performance Indicators) when riding outside versus riding on an indoor trainer (In this case, we used Kickr).

With the colder winter temperatures coming up, you’ll probably be spending more time training inside. Unfortunately, many cyclists feel that working out on an indoor trainer doesn’t match the sensation of real riding and that it’s difficult to match the feel of power output they get riding outside.

What factors affect the movement of the body on an indoor trainer compared to riding outside?

  • The bike is fixed in place. This means that riders can’t rock the bike side-to-side as they would when riding outside.
  • Torque is applied continuously on all 360 degrees of the pedal motion.
  • You won’t be riding into the wind, which makes it harder to regulate body temperature.

Now I’d like to show you a data comparison I made between riding outside versus riding on an indoor trainer.

The interval that I used in this test was 2-minutes long at a power output of 110–120% FTP, all conducted in my normal bike position. Let’s look at the data from 3 rides each on the indoor trainer and outside (Fig. 1).

Indoor Outdoor LEOMO TYPE-R

Differences in MPI between the indoor trainer and riding outside.

Now we compare the average values of the activity data from 3 rides each on the indoor trainer and outside.

LEOMO TYPE-R Indoor / Outdoor Motion Analysis

Key Takeaways:

  • DSS distribution: On the indoor trainer, only the right gets larger near the bottom dead point, whereas riding outside, both the left and right show a wider range, although the values are small.
  • Q1 and size of Leg AR: larger on the indoor trainer.
  • Pelvic Rot. and Pelvic Rock (On the indoor trainer: Rot > Rock, riding outside: Rot < Rock).

Summary

Until now it’s often been said that the movement of the body and the bike on an indoor trainer is different than riding outside, but here we can see the difference in numbers from the TYPE-R MPI’s that we evaluated. When you work out on an indoor trainer, bear in mind that the movement of your body will be different than riding outside, and it’s important to keep this in mind during your indoor training this winter.


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