Fatigue and How it Impacts Range of Motion in the Foot

Hello, this is Hunter Allen from Peaks Coaching Group! This past month, PCG hosted our 21st annual cycling camp in the breathtaking Blue Ridge Mountains. I was fortunate enough to have the opportunity to utilize the LEOMO TYPE-R to capture motion data from a majority of our attendees. The main goal was to identify when a rider fatigues based on a change in their motion. This could be the motion in their foot angular range (how far their foot moves up and down) or in their torso movement, which includes rotation, angle and rock. Fatigue and movement are fickle and sometimes hard to identify. Some riders will change the way their feet move when they become tired and others might move their upper body more. The calf muscles (gastrocnemius) hold the foot in place when pedaling and for many riders, when they fatigue, they are no longer able to hold the foot within the same range of motion. For some riders this means reducing their range of motion and for others, it means increasing it. Many riders will also change their upper body movements when they become fatigued. They tend to increase their torso rotation and/or rock and even make changes to their torso angle. With this in mind, we used a LEOMO TYPE-R to see if we can identify fatigue from a big picture view.

Our first rider completed the “long” day at camp which included a 95 mile ride with two mountain climbs, each lasting about 35 minutes. This rider had no change in his foot angular range throughout the entire ride, but when I compared the ride after the first climb (while he was still fresh) to the time after the second climb, there were some big changes in his torso data. First off, he lowered his torso angle near the end of the ride in order to become more aerodynamic and secondly, he rotated his torso more in the second half of the ride versus the first half which is a well-known indicator that a rider is fatigued and needs to use their upper body more to help with the pedaling motion. See figure 1.

Figure 1

In our second rider, we see an increase in the FAR or foot angular range near the end of the ride as he fatigued. This rider’s feet moved more once he became fatigued . I believe the reason for this is that his calf muscles were so tired that he could no longer hold his foot in it’s normal position . Have a look at Figure 2.

Figure 2

Our next example is yours truly. In our long ride, we have two mountains that we must climb up and over. On the first climb, I was relatively fresh and felt good the entire way up the climb, but from Figure 3, you’ll notice that my FAR became larger and larger near the end of the climb . I attribute this change to accumulated muscular fatigue over the week of riding. For the second climb, you’ll notice in figure 3 that the opposite happens and my FAR becomes smaller over the climb. While I was more fatigued on this climb, it also becomes less steep the closer you get to the top, and I believe that I was climbing very steadily during this time and that reduced my FAR. Overall, though you can see the trend that my FAR did increase in both feet throughout the ride, again, showing fatigue and how it impacts motion.

Figure 3

Why is it so important to identify fatigue? If we can pinpoint when fatigue sets in, we will have more insight into the endurance and stamina of the athlete. This allows the rider and/or coach to make informed decisions about the next steps in the athlete’s training plan. In future articles we will discuss how to make calculated decisions in training based off the data captured with the TYPE-R.

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