Running ability builds when you are always workout-ready-that is, able to fully meet the challenges on the day’s schedule. This obviously means from day-to-day your intensity will change, as a recovery day follows an intense day of speed-work, for example. As we’ve discussed in the past, if you are not running within a specific day’s goal intensity-wise, your gains will be
compromised, or worse, you will become injured.
One of the most effective ways to stay within your desired running intensity is to monitor your heart rate. By knowing at what percentage of maximal heart rate you are running, you are empowering yourself to adjust exertion in more subtle ways throughout the run. Common exertion goals correspond to specific heart rates.
For example, since the purpose of interval training is to increase VO2max, there are no gains to be made running intervals at a pace above your anaerobic threshold; the following table illustrates that your target heart rate for this type of workout, then, would be 80 to 89 percent MHR (max heart rate). (In the case of interval workouts, rather than running faster, optimize the time spent at this heart rate by adjusting the distances or the recovery times between intervals.)
For these heart rate percentages to have meaning, you must gain an accurate sense of what your MHR in fact is. To do this, you will need either to accurately take your own pulse, or wear a heart rate monitor. The usual formulas (for men, 220 – age = MHR bpm; for women, 226 – age = MHR bpm) are not acceptable estimates for MHR in trained runners. Using 205-1/2 your age is a more accurate calculation for those that are fit. Studies of very fit athletes reveal an even wider gap between the general public’s typical decreases in MHR with age and these elite runners, some of whom show no decrease at all in MHR for up to two decades. As Earl Fee writes in The Complete Guide to Running, “My own experience with a heart rate monitor indicates my MHR is of the order of 195 bpm but the formula above would predict only 150 bpm at age 70.”
Fee offers several methods for determining MHR. Here is one:
When in good shape, do fast intervals after a thorough warm-up. Run 4 x 200 m or 3 x 300 m at 95 percent effort with 5 or 6 minutes of rest in between. Immediately after the last interval, measure the heart rate.
Without a monitor, you can check your pulse to determine heart rate. Place the fingers of your left hand on the artery at the top inside of your right wrist. When a pulse coincides with one of the seconds on your running watch, call this zero. Count all beats for 15 seconds, and multiply by 4 for bpm.
While regular, daily pulse-keeping offers benefits such as indicating if you are sick or unrecovered from a severe workout, the main advantage to pulse-keeping is to keep each workout in the optimal range of effort. By carefully monitoring whether, say, you are just inside the anaerobic threshold, over time you will notice that at the same heart rate, your pace becomes faster. This is adaptation at work; its mechanism is achieving optimal training effort on a daily basis.
Having a target heart rate allows you to establish purposeful training. It is always good to ask, what is the purpose of this workout? It might be to establish a particular racing ability, provide stamina training, or simply to recover from a prior, hard workout to get you ready for the next one. Every training purpose will have a target heart rate associated with it.
As Olympian and exercise physiologist Pete Pfitzinger has written, “The greatest value of using a heart rate monitor is preventing yourself from accidentally training too hard on your recovery runs.” He feels that keeping your heart rate below 75 percent MHR lets your body recover so you can enjoy higher-quality workouts on hard days.
Once you set up a workout with a specific ability-building purpose, run the workout wearing a heart rate monitor. Your goal is to establish a set of target heart rate zones, and the advantage to using a monitor is that you can track your heart rate during the run. Monitors with a memory function are best; you can record and analyze your exertion patterns at home after the run.
Use a heart rate monitor to also gauge your exertion during cross-training activities. Many runners are not sure how hard, say, cycling is supposed to seem-their quads may tire easily, for example. Shoot for 70 to 80 percent MHR during your cross-training to ensure the workout is worth your time.
Most models of heart rate monitor involve wearing a band around your chest that transmits data to the display on your wrist. Newer models are without the heart strap and have a band that fits around the wrist. A basic heart rate monitor can cost less than $50, while countless additional features, from monitoring the temperature, altitude, or calories burned, can drive the cost upwards of $500. Monitors that can download data onto your computer tend to be the most expensive. You also may want to check if the monitor’s memory is large enough to store more than one workout.