Perhaps the most misleading guide an athlete can use for training pace is perceived exertion. Why can the signals our body gives us about how hard we are going be incorrect? Here is the answer. Most athletes are extremely motivated to get in top shape. However, if someone starts training wanting to push and progress as hard and fast as they can, effort outpaces fitness, and that level of intensity can set up a few things in the body that don’t serve long-term racing and fitness gains. One of these is that most likely this person will develop their anaerobic system at the sacrifice of never utilizing the aerobic system.
This sets up a few things that will make transitioning into a more sensible approach actually pretty tough. The first physiological negative that gets set up has to do with what happens to heart rate and pace by training too fast too often. Anaerobic training accesses carbs for fuel, and this happens at higher heart rates. If you are watching Super Bowl on the couch very little energy is needed and most will be provided through fat metabolism. If you are training fast and pushing the limits there is high demand for high-octane fuel (carbohydrate) that is well beyond the capability of our huge fuel storehouse of fat in the body. This is not necessarily a bad thing if done at the right times of your season (your speed phase of training). But a daily diet of fast training is like eating only one type of food. It does not balance the body in fitness terms.
Many things will happen in an athlete who trains like this. First, their heart rate will tend to elevate very quickly even at paces that feel moderate, conversational and are certainly sustainable. However, the pace that the heart rate jump happens at is not necessarily going to be fast. The end result is an athlete who trains at a relatively high heart rate in relation to pace. And even though perceived exertion may be in line with their pace it certainly will not match what is going on with their heart rate (moderate perceived exertion with high heart rate).
What happens when you strap a heart rate monitor on this person and ask them to drop their heart rate from say 180 to 140? They will have to crawl to keep their heart rate below the lower number, and their perceived exertion will plummet to a feeling like the workout is not a workout at all. However, if they do not do this and continue to train by perceived exertion their body will be kept in an out-of-balance state, one that has almost no aerobic metabolic capacity. Aerobic fitness is the cornerstone of endurance athletics, of good health, and of sustainable improvement over time without risking injury, illness or burnout.
Another thing will happen with the chronic high heart rate athlete. Their max heart rate will rise well above what one would predict based on their age. If a training zone is set as a percentage of this out-of-balance high heart rate, all training will be too high and keep them in a chronic state of imbalance.
I was this type of athlete in the early days of my career. Coming from a swimming background I was programmed to push my limits in every single workout. My comfortable training pace, although not blisteringly fast, was at a heart rate that was about 30 beats above what would help me develop my real base of aerobic fitness. In addition, my max heart rate was about 215, which was almost 20 beats higher than it should have been based on my age. (Predicted max heart rate is 220 minus your age).
The first session I used heart rate rather than perceived exertion to set my effort level was shocking. I had to slow down over three minutes per mile from my normal training pace just to keep my heart rate from skyrocketing over what was my aerobic max at the time of 155 beats per minute. The pace I was running would not have been fast enough to beat guys twice my age. But I stuck with it. Over time with lots of base and just the right amount of high intensity training my aerobic pace dropped to just under a 5:30 mile at 155 beats per minute. My max heart rate also plummeted to about 178 beats per minute, yet I was going significantly faster at that lower max than I was at 215 beats per minute when I was in a state that was out of balance.
Take Away Wisdom:Perceived exertion is not a good determinant for maximizing your training. High heart rate training leads to high max heart rates and high training heart rate that can feel comfortable, but this doesn’t translate into actually GOING faster at those high heart rates. Only by developing your aerobic base can one maximize the potential of doing intensity training.
Utilizing Pace and Watts.These two tools can become important feedback while using heart rate to regulate overall speed in a workout. Pace used while running will give you instantaneous feedback on how your fitness is progressing. If you run a specific training loop faster than the week before, great! If you are slower, it is feedback that you either need to alter the type of training you are doing (maybe adding in speedwork), or that your body is under some form of stress that is inhibiting your fitness improvements. More often than not, going in the wrong direction with your fitness is linked to the second reason. Stress works opposite to aerobic development and can cause your pace to get slower rather than faster
Watts will tell you similar things and a whole lot more while cycling. On the bike there are some key factors that influence how fast you go. Of course fitness is the main one. But in addition your cadence rate and position on the bike will also play an important role. Looking at your watts, cadence and heart rate all at the same time can help give you that sweet spot that maximizes your speed.
Pick a heart rate that you want to hold, and then alter your cadence rate to see how that affects your watts. Do this in slightly different positions on your seat as well as changing different muscle groups you focus on while generating your power for the pedal stroke until you find the one that optimizes your power output for your speed on the road at a specific heart rate. Experiment with relaxing yourself at different points in the pedal stroke to up the power output without upping the heart rate. It will take some time, but it is worth the feedback that these three factors give you to help maximize speed.