My foot has started giving me a bit of problems so I have decided to try reducing my heart rate from 133 to 125. 133 is Maf for me so 125 is almost Maf-10. My typical run would be about 12 km with an average pace of about 4:42/km and an average heart rate of 133. Today I ran my usual 12 km run, typical time and weather conditions and my heart rate averaged 123. My pace only dropped to 4:48, only 6 seconds/km different. Is this typical or does it suggest I should really be reducing my MAF heartrate target?
Maybe it was just an anomoly? In general, I look for trends. With HR, so many things can affect it on a particular day. So, I would not be that concerned with a single reading. Other than that, I have no advice. It does seem strange that your HR is so much lower for the pace on that day.
I don't think it really suggests anything. On this day, your pace was 4:48 at 123 bpm, which is slower than the pace you run at 133 bpm. It is what it is---might be different tomorrow. Hope your foot heals quickly.
Log PRs Crusted Salt comics #192 (NSFW)