heart rate and running

Question
Hi. I'm 44 YO and have been running for about eight months now. I've done 2 half ironmans, 2-21k, 1-42k. When I run, I notice that my heart rate hovers at 144 at about 6-7 min/km pace. If i try to raise my heart rate, I can only go 154 bpm, before I give up due to lactate build-up. But when I bike, I notice that I can maintain 165 bpm no problem. I wonder if my inability to raise my running heart rate is keeping me from improving my run time. How can I raise my HR to run faster? Or should I even try to?  

Answer
Hi Pax
Since your quite new to running your cardiovascular system and arterial network and muscular skeleton is not fully developed and over time your performance will increase.Don't worry about your heart rate,just focus on your training program.Your max heart rate is aprox 176 so running at a pace heart rate is about 80% at 144 and your red line just before lactate build up is between 85% to 88% 149 to 154.Over time with good training your vascular system will be able to work harder and faster while still maintaining your 85% to 88% lactate threshold to new PR,s.If you have other questions just get in touch Pax.


All the best

John