By PCG Master Coach Hunter Allen
This past month, I was able to gather motion data on many of
the cyclists that came to our 21st annual cycling camp here in the
beautiful Blue Ridge Mountains. The main goal was to be able 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 the foot moves up and down), or in their
torso movement, which includes rotation, angle, and rock. Fatigue and movement
are fickle things, and sometimes hard to identify. Some riders will change the
way their feet move when they become tired in a ride, and others will move
their upper body more. The calf muscles
(gastrocnemius) hold their foot in place when pedaling, and for many riders,
when they fatigue, they are no longer able to hold the foot within the previous
range of motion. For some riders, this
means reducing their range of motion, for others, it means increasing it. Many
riders will also change their upper body movements when they become fatigued,
and 99% of the time, they will increase their torso rotation, or rock, and even
change the angle of their torso. With this in mind, we looked at all of the
riders using a LEOMO TYPE-R at the camp to see if we could identify fatigue
from a big picture view.
Our first rider completed the “long” day at camp, which is
95 miles over two mountains, each mountain stretch being about 35 minutes long.
He had no change in his foot angular range throughout the entire ride. However,
when I compared the ride after the first climb (while he was still fresh) to
the ride after the second climb, then there were some big changes in his torso
data. First off, he was no longer able (or willing) to keep his upper body as
low as he could when fresh, so he was less aerodynamic at the end of the ride
than at the beginning. Second, he rotated his body 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.
In our second rider, we see an increase in the FAR, 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,
and could no longer hold his foot stable.
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 to accumulated muscular fatigue over the week of riding. For the
second climb, you’ll notice, also in figure 3, that the opposite happens, and
my FAR becomes smaller over the climb. Even though I was more fatigued on this
second climb, the climb itself also becomes less steep the closer you get to
the top. I believe that I was climbing very steadily during this time, and that
reduced my FAR. The two long green dashed lines in Figure 3 show that the
overall FAR continued to increase throughout the entire ride, which demonstrates
increasing fatigue and how it impacts motion.
Why is this so important to be able to see fatigue? If we
can see where fatigue occurs, then that gives us more insight into the
endurance and stamina of the athlete. This will allow the rider or coach to
make important decisions about the upcoming type of training needed for the
athlete. (More on how and what decisions to make will come later in another
article.)
