What does the blue line indicate at the end of this HR graph?

[LZH]

I've seen this blue line on other days.  My HR at the end of the graph was 53, 6 beats lower than RHR.

My HR at the end of the graph was 53, 6 beats lower than RHR.

[LZH]

This photo is clearer

[Dominique]

I would say the blue line is the visual representation of your lowest HR zone (not in any zone) in the iOS app. This is based on my observation of the same graph on my Android phone and on my iPad. In Android, the colour of the line varies from yellow (lowest HR) to red (highest HR), with various shades of oranges in between.

Just have a look at a full day and you should see blue not only at the end of the graph (as on your snapshot), but also during the night. Here is a sample graph of mine (from the iOS app):

See: blue line across the day, when HR was lowish.

[LZH]

Your graph surprises me. I can go a month or more without seeing blue on my graph.  When I do, it's for very short periods of time, usually during the day.

I'm also on Android.

[Dominique]

Weird, I don’t see any blue line on any of my HR graphs on Android. I only see gray dashes when I’m recharging my tracker (it’s a Surge, and I need to recharge it often when I use GPS, which drains the battery like crazy). Maybe it’s something specific to the Charge HR? 

[MarciM]

The colors much OS specific. I'm looking at mine on iOS and I have a lot of blue everyday, which indicates anytime you aren't in a fat burning or above heartrate zones.

[JohnnyRow]

I agree the colors and gradations are quite different on iOS and Android.

My Android colors look just the same as the fitbit.com dashboard. On Android, the lowest I get is bright yellow, not that blue or even green, including nights when my heart rate gets 5-10 below RHR.

[LZH]

After reading all of your replies, I understand what's going on.  I usually spend all of my day in fat burn, cardio or peak zones. No blue should show on my graph. The majority of the day  is in cardio.  My peak is only 80, so my zones are very tight. I've looked through my graphs for the past 6 weeks. 1 day out of 10 has some blue, but only an hour or two. I would greatly appreciate if you would read the rest of this post.

This means my level of exertion is way too high for my body to handle.  I will try to spend most of the day in bed until this gets more reasonable. Obviously lying back in a recliner requires too much effort for me at this time. This type of graph is typical of most of the 3 Million people in the US with ME/CFS. Due to crippled mitochondria, our bodies are constantly in a state of severe overtraining.  While physical therapists are no help for us, exercise physiologists can give us appropriate advice, and help us improve. They actually understand some data that indicates what's happening in our bodies.

The majority of people have no clue of the severity of this disease, nor how widespread it is. 3 million is a conservative estimate. CDC estimates have been as high as 6 million in the US alone.  Yet there is almost no federal research funding available for this disease. There is far more funding available for diseases that affect far fewer people.  Even a minor thing like male pattern baldness receives more government funding.

I hope that someday there is such a thing as a Race for ME/CFS. This is the reason I mention this disease when I ask questions here.  ME stands for Myalgic Encephalomyelitis.  CFS stands for Chronic Fatigue Syndrome.  Unfortunately CFS just sounds like many people's busy lives.  Once ME/CFS hits, we can go from busy and athletic lives to bedridden almost overnight.  Most people with this start out feeling bad, but try to maintain as much of their former life as possible. This causes more damage, leading to ever more severe illness. If newly ill people understood the necessity of deep rest at onset, they will be able to improve a great deal, instead of spiraling downward. 

40 years ago, when I got sick, this was not understood at all. As a formerly active 19 year old, I did as much as I possibly could, interspersed with barely being able to drag myself to work.  I couldn't do anything else like cooking or laundry, and wasn't as sharp as I should be at work. Other times I was extremely fatigued, but could function a lot better.  When I felt somewhat better I added every activity I could, though not things like tennis or long walks.  I continued this cycle of push/crash until I was bedridden 10 years later. For 30 years, I've alternated between bedridden and housebound.  I tell you this because it breaks my heart to see this happening to so many people today.  A few will be severely ill immediately.  But most people who develop ME/CFS can have much better lives than I've had. They don't because neither they or their doctors know any better.

[LZH]

Ugh.  I just looked at my graph for the month of August.