Polar RS800CX Fitness Electronics User Manual


 
HRV indicates the fluctuations of heart rate around an average heart rate. An average heart rate of 60
beats per minute (bpm) does not mean that the interval between successive heartbeats would be exactly
1.0 sec, instead they may fluctuate/vary from 0.5 sec up to 2.0 sec.
HRV is affected by aerobic fitness. HRV of a well-conditioned heart is generally large at rest. Other factors
that affect HRV are age, genetics, body position, time of day, and health status. During exercise, HRV
decreases as heart rate and exercise intensity increase. HRV also decreases during periods of mental
stress.
HRV is regulated by the autonomic nervous system. Parasympathetic activity decreases heart rate and
increases HRV, whereas sympathetic activity increases heart rate and decreases HRV.
HRV is used in the Ownzone, OwnIndex, and in OwnOptimizer features. It can also be monitored on its
own using the training computer. If your HRV changes at a given pace and heart rate, this may indicate a
change in your training load and stress.
Running Cadence and Stride Length
Cadence* is the number of times the foot with the stride sensor* hits the ground per minute.
Stride length* is the average length of one step. That is the distance between your right and left foot
contacting the ground.
Running speed = 2 * stride length * cadence
There are two ways to run faster: moving your legs at a higher cadence or taking longer steps.
Elite long distance runners typically run with a high cadence of 85-95. On uphills, typical cadence values
are lower. On downhills they are higher. Runners adjust stride length to gather speed: stride length
increases as speed increases.
Yet one of the most common mistakes novice runners make is over-striding. The most efficient stride
length is the natural one – the one that feels most comfortable. You will run faster in races by
strengthening your leg muscles so they take you forward with a longer stride.
You should also work on maximizing cadence efficiency. Cadence does not progress easily, but if properly
trained, you will be able to sustain it throughout your runs and maximize your performance. To develop
cadence, the nerve-muscle connection needs to be trained - and reasonably frequently. A session of
cadence training a week is a good start. Incorporate some cadence work into the rest of your week. During
long easy runs, you could include some faster cadence every now and then.
When training for longer running events (½ Marathon, Marathon or longer), it may be helpful to monitor
cadence. A low cadence at expected race pace can cause problems later in the event, as your legs tire.
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56 Background Information