I've been cycling for many years and just recently bought a Garmin 500 with cadence and heart sensor. I'm fascinated by all of the data but at a loss for how to use it to train. I've been reading about VO2 max, power, LT, etc. but can't make heads or tails of it. Is there a way to use the data the cycle computer to train and become stronger? I know this question is a bit vague but I'm just wondering where to start.
Thanks so much!
Sorry to take some time on this. I actually know a bit about this because I just finished renewing my USAT coaching license and had to review a bunch of material on training methods. To simplify, VO2 max is a measure of your maximum efficiency processing O2 through your lungs to your muscles. Generally, you need to have an oxygen analyzer and some serious equipment to find your true VO2 max. If it is on a watch/computer/electronic device, the machine is just estimating it. VO2 max is something you have an exercise physiology lab test you for, so it really isn't a good training parameter.
Of the systems you can actually monitor real-time, the most rudimentary is heart rate. The HR strap gives you a good readout of what your HR is, so if you can use the Garmin to run a set distance at a certain pace and your HR is lower, then you are getting more fit. HR is generally used with time for intensity level training. For instance, if you are doing a long slow distance run, you keep your HR aerobic (approx. 75% of your maximum HR (best to be supervised when you find your max HR, but you can ballpark it as the highest you have EVER seen your HR). For instance, if your max HR is 200, then aerobic is 150 HR or lower, etc. There are plenty of charts available to give you an idea of percentages of max HR for different levels of training exertion, such as lower aerobic, upper aerobic, tempo, and anaerobic. You would use HR to set up, for instance an interval day: 15 min aerobic run, then 6 x 2 min tempo/2 min aerobic, and remainder to 40min aerobic (that was my run workout today). HR has its drawbacks, though, because many factors can affect your HR rate, such as lack of nutrition, lack of rest, dehydration, sickness, caffeine. Thus, HR is not the most accurate training parameter.
With biking, you can use power. I really like that, because the power meter doesn't lie. Again, you figure out over time what your output levels are on the bike, such as 200 watts for aerobic, 220 for upper aerobic, 250 for tempo and 300 for functional threshold power (short term power). Once you get a feel for the power levels you can sustain, you can use those to build workouts. The nice thing about power is it doesn't change as a measurement. You may feel terrible one day holding 220 watts, but it still is 220 watts. If you up your average wattage over 30 minutes from 220 to 240 by the end of the year, you know you are fitter.
The general levels of effort are roughly broken down by the systems that your body uses to power your muscles. Three levels of different power systems exist: the first is aerobic, when your body can get enough oxygen and can clear the waste products fairly efficiently (up to 75% max heart rate, generally). When you cross that magic level of 75% or so, your body generally can't get enough oxygen fast enough, so it switches to an anaerobic system using stored glycogen. The point when it switches is the lactate threshold (LT). I think of anaerobic as when your body is running on limited fuel stored in the muscles and the byproducts of non-oxygen reactions begin to back up in your muscles (giving the so-called "lactic acid burn"). The final power system lasts even less time (the ATP/CP system). This is that really short supreme effort-type exertion level. That burns energy so fast that it really can't last more than a minute or two at best.
Where to start? Start by looking up muscular energy systems in Wikipedia. Then look for a book on HR training. Once you understand the levels of HR, then you can read up on training with power (wattage). The training resources really just depend on what you are trying to accomplish. If running, there are marathon books. If biking, there are a ton of online cycling books and coaching systems. Even though I am a coach, I use Training Peaks to set up my training program.
I know this is just scratching the surface, so feel free to ask questions.