Sunday, July 24, 2011

Heart Rate Training Zones

A Zephyr heart rate sensor can be connected to the My Tracks  Android smart phone training data application.

Once you get past the novelty of seeing a heart rate during exercise you'll want to use it for selecting a  target rate or at least characterising your exercise effort. There are simpler methods, but using the more accurate Karvonen method,  the target rate is determined by the maximum rate, resting rate and desired training zone. Training zones can vary in number and definition with five being a common number as shown in Table 1.
Zone 1 Zone 2 Zone 3 Zone 4 Zone 5
Fitness Training Zone 50-60% 60-70% 70-80% 80-90% 90-100%
Light Easy Aerobic Anaerobic VO2 Max
Walking Jogging Running Hard All Out
3-Fitness & Wellness 60-70% 70-75% 75-80% 80-90% 90 - 100%
Overdistance, strength Endurance, strength Endurance, strength Intervals, hills, race/pace Racing, speed

Table 1. - Training zone definitions from Fitness Training Zone and 3-Fitness & Wellness. The Fitness Training Zone website provides a good explanation of each of the zones.

Maximum rate can be determined by methods involving heart rate measurement at sub maximal exercise levels then adding a margin or a variety of related methods which ultimately aim to get heart rate to the maximum possible for a short period. The one tried here is  the 2-4 Minute Test . The results are shown in figures 1 and 2.

Figure 1 Determining maximum heart rate for a male age 50

Figure 2 Determining maximum heart rate for a female aged 16

To generate these graphs export data from My Tracks in TCX format then open in Microsoft Excel 2007. TCX is an XML format and XML tables can be directly imported into an Excel spreadsheet.

The resting heart rate averaged over 4 minutes for the 50 year male was 55 bpm and for the 16 year old female 81 bpm. Applying the Karvonen method leads to the heart rate zones in table 2.

Zone 1 Zone 2 Zone 3 Zone 4 Zone 5
Male 50 124-138 139 - 152 152 -166 167 - 180 181 - 194
Female 16 129 - 139 140 148 149 - 157 158 - 168 168 - 177
Light Easy Aerobic Anaerobic VO2 Max
Walking Jogging Running Hard All Out
 Table 2. - Training zones for a male aged 50 and female aged 16.

At 159 bpm driving a Go Kart takes the 50 year old male into the aerobic running zone, at 126 bpm walking up a mountain takes the 50 year old into the light walking zone and riding a bike for transport to 136 bpm which is also in the light walking zone.