HRM-Run Mile Dropouts

I can't shed any light on why...but I am in a similar situation. My heart rate strap is also dropping out regularly and it is only a few months old. I am therefore guessing it's the software. 

It is very frustrating. Was running intervals today and dropped out 9 times in 18 minutes. Happens every time I'm running at a quick pace. 

Was using my Forerunner 220 for 5 years and HR strap was always consistent. My new 245M drops out regularly. 

Former Member I changed the battery over last week and its kinda stopped doing it now. When it would do it on the 245, it would be during workouts plugged into the watch not off a standard run but the past few workouts its been stable. Maybe try changing the battery.

Thanks very much, I will definitely try that. Mine was the exact same. It holds up well on slower runs...but was dropping out regularly on workouts. 

The strap is relatively new so I would have thought the battery was ok..but I will try changing it anyway.

Thank you for the advice. 

Former Member This was from yesterday. The first drop is off the warmup of 15 mins when I stretched and the watch was paused in the workout mode (so that was expected). The next one to occur was near the end of the workout (just after 7 miles) on the actual watch, giving me a workout ended message where I ran back home for an extra few mins. So I do believe it's all software related. I was the same as you, my HRM is not old and the batteries do last a long while. But this result with the new battery is far better than I had been getting.

Thank you very much. I will certainly try that later on. I appreciate your help. 

You can see from screenshot how many times it dropped yesterday:

Just an idea:

If you run in a t-shirt made of synthetic fabric, then electrostatic charge can accumulate on the fabric interfering with the measurements on the strap's electrodes. I experienced a similar phenomenon on two very different devices (FR310XT and FR735XT) and two very different straps (HRM-Tri and a cheap Adidas-branded hrm) and any combination of these would give me the same result. So I assumed that either my heart is doing really weird things, or there is an external reason. Once I tried working out bare-chested, and the problem was gone. Hence my hypothesis about synthetic fabric.

I know that running naked is not always a feasible solution, so you might try running in cotton clothes, or making the strap very wet (like soaking it in water just before workout).

Out of curiosity, is this happening at lap intervals. In other words, do you have auto-lap set a 1 mile and each time it ticks over, it drops out? If you change the lap interval, or manually hit the lap button, does it do the same thing? Some of the other responses makes me think it might be related. For example, if it is dropping out 9 times in 18 minutes while doing intervals, this would make sense if there were 9 intervals in that 8 minutes. And it makes sense if someone saw it when their workout was complete and the workout ended message shows, as that is recorded like a lap interval.

For me at least I don't think it's linked to the autolap. I get what you're saying though and it's a good suggestion. There doesn't seem to be a pattern but rather it drops out at random times.

For example I did a 6 mile tempo last week and it dropped out 4 times in the first 9 minutes, 4 times in the next 15 minutes...and was perfect for last 15.

My forerunner 220 didn't seem to have any issues with the same HR strap. 

Thanks for help all the same. 

This is a good point as I did notice that the auto lap in the workout mode would do this but again it was happening at other random points as well. Like last year it was all fine, I think ever since the software went above 4.0 this started to occur. I also wet the HRM strap thoroughly before use and most often using a high quality shirt or singlet so not sure it can be linked to the material before I start running naked

I have exactly the same issue (FR245M). It looks like it started appearing after the upgrade to 5.00. I have relatively new HRM (2-3 months old).
Especially, when I doing interval training, the watch is constantly dropping the connection with HRM at regular spaces. Attached screen from training.

When I connected this HR strap to old FR235 and run intervals everything was OK. I suspect a software problem.