GCN has a new vid out today on torque training so I decided I’d write a post on something I’ve been doing for the last two months or so: moderate cadence torque training. Note that I am not referring to low cadence work, for which there are all sorts of articles, studies, arguments, posts, etc., generally referring to 5 minute grinding efforts at 50 or 60 rpm.
In a nutshell, I noticed that on the trainer that for any given ride, I tend to be around 100 rpm because it feels easier on my leg muscles, but easier doesn’t mean more effective or better training. To improve you need to be uncomfortable. Back in “the day” I always rode at 90 rpm while sitting on the mag trainer, so for all endurance/Z2 rides I increased the resistance on my kickr and dropped the cadence to 90; note that power stays within zone (I’m changing torque, not overall watts). I have also been doing two sweet spot rides at even higher resistance with cadence 80-85; again, though the torque is higher, I am staying in zone. If I were to pedal that resistance at 100 rpm I’d be well above threshold.
Despite being in the proper zones for Z2 and SS efforts, my legs are doing more work and they feel it. There is a significant difference in perceived exertion, effort, and focus. I haven’t seen much that analyzes torque physiology, but here is my theory: 1) increased torque means increased muscle fiber recruitment, which is a neurological effort; 2) the neurological recruitment of these additional muscle fibers, which don’t normally do this much (or any?) work during endurance/SS training, forces the cells to adapt to a) increased mechanical stress on the actin/myosin myofilaments, thus stimulating the production of actin/myosin for structural improvement, and b) increased ATP demand, which means increased respiration, energy production, and metabolism, which leads to development of related organelles, including but not limited to everyone’s favorite - mitochondria. In other words, while the first step of higher torque is neurological, that is merely a stepping stone that leads to increased cellular structural and metabolic adaptations for a given period of time in zone. Of course, there are limits regarding torque and cadence - if you’re doing a SS effort and you can only pedal at a given resistance for 5-10 minutes @ 60 rpm, you’re missing the point of the workout and need to increase your cadence and decrease the resistance so you can do repeats of 20+ minutes in zone.
Additional thought regarding endurance rides: many coaches point out the need for the long ride in order to get to the point where your slow twitch fibers are so tired that Type 2A contribute to the work, thus increasing their fatigue resistance. My zone 2 rides are 2.5 hours and I just don’t have it in me to sit on the trainer for 4+ hours. Maybe I don’t need to, if 2.5 hours with higher torque and thus increased muscle fiber recruitment brings in the additional fibers earlier than does longer, lower torque pedaling. I’m not performing muscle biopsies on my legs, but they are definitely more fatigued staying in zone at 90 rpm/higher torque than they are at 100 rpm/lower torque for 2.5 hours.
