Lisa Sabin’s - Running And Being

As I’ve began to run again after taking time off to recover from plantar fasciitis, I have noticed that my HR has been fairly high during most of my runs.  I thought that maybe it’s because I’ve been training in lower zones, i.e. my HR is usually around 160 if I am out on my bike, and 150 indoors.  Swimming doesn’t get my HR above 150. 

I’ve been curious about my heart rate being lower on cooler days vs. hot afternoons.  I know that heat contributes to dehydration and training is more difficult in warmer temperatures. 

Heart rate increases at high temperatures. Your heart rate is higher when running on a hot day. As the temperature increases from 60 degrees to 75 degrees, a runner?s heart rate at a given speed increases by about 2 to 4 beats per minute. When the temperature increases from 75 degrees to 90 degrees, you can expect your heart rate running at a given speed to increase by approximately 10 beats per minute. High humidity magnifies the effect of high temperatures on heart rate.

To gain the same benefits as on a cool day, you should increase your heart rate zones by 2 to 4 beats per minute when the temperature is in the 70?s and the humidity is low. On a high humidity day in the 70?s or a low humidity day in the 80?s, you should increase your zones by approximately 5 to 8 beats per minute to correct for the heat factor. In more extreme conditions, such as a high humidity day over 80 degrees, you cannot accurately adjust your heart rate zones for the conditions. On the most brutal summer days, it is wise to adjust your training schedule to avoid high intensity training.

http://www.pfitzinger.com/labreports/heartrate.shtml

Running is more intense for me than cycling.  I know what my personal training zones are and  I always have a higher HR when I’m running vs. cycling.  I’ve noticed now that I am about 3 weeks into running again that my HR is still fairly high (most of my runs have been on hot days in the afternoon) but my pace is beginning to gradually increase.  I think there are two things happening here,  I am running in conditions that make it harder, so I will naturally have a higher HR,  and I am beginning to see a training effect.  I am becoming conditioned to running again. 

Workout:

• Type: Cycle
• Date: 08/30/2007
• Time: 17:30:00
• Total Time: 00:00:30.00
• Calories: 200