BIKE TECHNIQUE 101: HOW TO IMPROVE YOUR BIKE TIME USING CADENCE
What is CADENCE? Cadence in cycling refers to the number of revolutions of the crank per minute (RPM). Roughly speaking, this is the speed at which a cyclist is pedaling/turning the pedals. Most bicycle computers are able to measure cadence. The sensor is usually at the end of the crank, and the reading is relayed to the cyclist via an LCD display, typically mounted on the bicycle's handlebars.
Cyclists typically have a preferred cadence at which they feel most comfortable. Recreational cyclists typically cycle around 60–80 RPM; racing cyclists around 80–120 RPM and sprinters up to 170 RPM for short bursts. The professional racing cyclist and Tour de France champion Lance Armstrong is known for his technique of keeping up high cadences of around 120 RPM for hours on end; a testimony to his efficiency.
Why should you be using a higher cadence? Cadence influences the number and range of gears that are appropriate for particular cycling conditions. The recommended cadence for a triathlete is between 90 and 105 RPM’s.
Why such a high turnover rate? Well, it has a lot to do with muscle fiber type and how those fiber types are recruited during exercise. When utilizing a cadence of 90 RPM's, you are recruiting more of your Type I muscle fibers or "slow twitch" fibers. These fibers utilize aerobic (oxygen) forms of energy, which allow you to run or cycle for long periods of time without fatiguing as quickly depending on your level of conditioning. When pushing the “big gear” with a lower cadence of lets say 60 to 80 RPM's, you are likely recruiting more of your Type II or "fast twitch" fibers, which are larger and more powerful. The downside is that these fibers utilize mostly anaerobic (little to no oxygen) forms of energy, which are great for short powerful bursts of speed. Think hard track workout (Type II) vs. endurance training for a marathon (Type I).
Your body does use both fiber types during exercise, but at a higher RPM you will use a higher ratio of your Type I vs. Type II fibers because muscle fibers are recruited smallest (Type I) to largest (Type II) according to workload. Plus you don’t want to hurt your knees by overloading the joint with too much pressure.
One of the biggest reasons to utilize a cadence of 90-105 RPM's is that as a triathlete, you still have to run once you get off the bike. Running isn't going to be very easy or fun if your muscles are already extremely fatigued from pushing a heavier gear at a lower cadence. At the higher cadence, you will not be as fatigued, and your run will be much easier.
How can I improve my cadence? Using a higher cadence seems hard at first. Like a good golf swing, it takes time and practice to adapt your self to this style of riding.
Here are some training tips for those seeking to improve their cadence: • Firstly, shoot for 2-3 sessions of cycling per week, 3 being the most ideal - it will help your body to adapt faster • Make sure you are warmed up at your current RPM for 5-10 minutes before beginning an interval at a higher RPM • Start at the lower end of the range, @ 90 RPM’s • During a 1-hour workout perform 5-10 minute intervals @ 90 RPM’s mixed in with 5 minute intervals at your normal RPM to help you adapt • Focus on using proper stroke technique, driving downward with your heel • Spinning at a higher rate initially is going to be taxing on your cardiovascular system - you will most likely need several sessions to adapt • You may want to utilize a HR monitor to track your cardiovascular progression - initially your HR will most likely increase, maybe even near maximum, but as you progress and become more conditioned it will drop to a more acceptable level • As your body adapts to 90 RPM, you should find it easier to do an even higher RPM like 95 or 100 if you choose to
By following these training tips, you should feel better after your bike ride. Switching from bike to run is difficult regardless, but your run should feel better to you.
Contributors: Brought to you by VBS TriTEAM members: Wayne Brown Cory Bultman Terence Reuben, PT, CPT, CSC Joe Manning