Review of Apple Watch Nike+, Fitness Tracking, and Heart Rate Variability

Apple Watch Nike Plus Series 2 Review_
You asked … Apple Watch Nike Plus Series 2 Review_ (View on

Last year I wrote a review of the Apple Watch Series 1 as a commentary on the transition from one wearable (Google Glass) to another (see: Apple Watch Review, by a former Google Glass Explorer )

That’s all past now; this is a review and thoughts on the new Apple Watch Nike+ (Series 2) and associated ideas on fitness tracking and heart rate variability.

Huge improvement in many areas

Let me count the ways:

  • Battery life – I no longer worry about it after a day’s worth of use. I’ve turned off the battery level complication altogether. If I did any sort of workout activity on the Series 1, I would need to recharge, since the heart rate monitoring involved would drain about 20% of the charge.
  • WatchOS 3.X (pronounced similar to “Nachos” :)) – Way faster. The dock gets me to what I want quickly. With the Series 1 device, I didn’t even bother to try to open any apps. With Series 2, I am more likely to bother to open an app or two. I can actually read an email here or there.
  • Nike Run Club app – It’s pretty good, with 95% of what someone like me needs – GPS tracking, Pace voiceover, quick to start quick to stop. There other options available, this suits me fine.
  • Watch band and Watch Face – The Series 1 band was a little challenging to put on in the morning, the Nike+ watch band is easier (more perforations)
Apple Watch Nike Plus Series 2 Review_-3
Putting my biases out there. Note my choices. From Apple Watch customer survey. Apple Watch Nike Plus Series 2 Review_-3 (View on

The main benefits of the watch are still notifications, which are really handy, and fitness tracking, which is a benefit but not the primary one. In my opinion Watch is transitioning to be more of a personal computer than a fitness tracker, which seems appropriate based on what we’re learning about fitness tracking for populations (see below).

One slight annoyance, the place where the digital crown sticks out can cause Siri, the somewhat, but not really useful, personal assistant to get activated while wearing weight gloves (since this watch is designed for athletes, I thought I’d mention it).

Fitness Tracking?

In 2016, we know more about wearables and fitness than we did in 2015, and that is that only about 10% of people continue to wear a fitness tracker after 12 months, and wearable fitness trackers are not associated with weight loss or increased physical activity. (I’ve read the commentary/critique about these studies and I think this assessment is valid – see these blog posts, let me know your thoughts).

2016.10.29 Apple Watch Nike+ OOB Experience 08549
“Designed for Athletes” (and maybe not the general population) 2016.10.29 Apple Watch Nike+ OOB Experience 08549 (View on

I’m clearly one of the 10%, I know it, and I think Apple has designed the product with the 10% in mind – noticing the wording on the box – “Designed for Athletes by Apple and Nike.” To me, that’s a recognition that wearables may not work for everyone for fitness. Based on what we’re learning, this seems reasonable to me.

In my 10%-ness, I admit I try and close the rings every day. I’ve turned off the breathe app and all of the badges, I’m probably more of a 20%-er when it comes to that stuff.

Just Read: I’m in the 10% (who still wears their fitness tracker)

Being Social

New in WatchOS 3.X is the ability to share workout information with friends, and Watch does it in a very private way – without announcing it to you after you set it up. In the beginning it feels a little creepy, but after awhile the level of noise surrounding this feature is about right – you don’t need to post on a social network, and you don’t need to take a lot of steps to share. The share-ee is prompted to respond via messaging if they feel like it, or they can just smile, which I do when I see a friend’s workout.

Health tracking in general

Watch (and phone) generate a lot of data – just look at the Health app – hundreds of heart rate measurements a day. Same with measures of activity.

Apple Watch Nike Plus Series 2 Review 3504
Heart Rate Measurement (Yes, but so what…) Apple Watch Nike Plus Series 2 Review 3504 (View on

As noted last year the concept of steps is minimized and calories promoted, which makes sense. Just because you can measure something (steps) doesn’t mean  it’s useful, and with a more modern appliance that less useful measure (steps) is in the background.

Given the data about impact of wearables not being as useful for promoting health, we may find the same for the plethora of other health things Watch is measuring.

Doesn’t mean Watch is not useful, it just may grow into usefulness as a computer over time. As the wearable market begins to decline/mature, fitness is just a segue to another functional place.

Heart Rate Variability – Just Because You Can Measure Something Doesn’t Mean You Should – And Watch Can’t Really Measure it Anyway

I was re-exposed to Heart Rate Variability  (HRV) as a measure of something potentially useful in health at Health-Foo 2013. I decided not to write about what I learned then, but I did cover it about a year later in passing as more information started coming out about the usefulness of wearables.

I call it “re-exposure” because I learned about HRV in obstetrics. As the quote goes:

Variability is the law of life… (Osler)

In a fetus, sustained loss of heart rate variability is ominous and predictive of neonatal death. These neuro-endocrine pathways exist and mature into our adulthood and may also predict unhealthy outcomes.

The can be extracted to all of humanity – a species with no variability is an ominous sign. Diversity allows humanity to survive.

I did a preliminary literature review in 2013 and I felt there was promise in using this newish physiologic measure that wasn’t really available in medicine because it wasn’t easy to measure.

That plus the fact that Apple, Inc. has been hiring well known experts in biometric measurement made me believe that they were working to make HRV a part of Watch and by extension our lives.

I did a re-review this year (list of papers below) and now I’m not so convinced.

Measuring the beat to beat and longer term fluctuations in the speed of one’s heart has been studied since the advent of the ECG (1895) (well probably longer than that – see this timeline) and with more modern devices that can measure it easily, more intensively. If you have a hammer everything is a nail.

A heart beat with less variability is one that’s probably under the influence of the sympathetic nervous (“fight or flight”) nervous system and therefore a marker of stress. Or maybe a marker of the overall functioning of the autonomic nervous system balance. As discussed in the research, this has implications for people with diabetes and especially with myocardial infarctions.

The challenge is

  • HRV probably is not as conveniently measurable as people would like. It requires electrical signal measurement, and Watch uses light pulses. People are trying though. In the meantime, a device that measures electrical activity is needed and those are typically not worn on the wrist.
  • Its not clear, except in specific situations, how knowing your HRV would change (hopefully improve) your health. For a population, that is. As it is now, I can review my heart rate which is nice, but, so what. My heart rate goes up when I exercise, not a new revelation.
  • Medicine is riddled with the disasters of over measurement of things. More data is not always better, and it can be counter productive, even harmful, even deadly. Doesn’t mean people shouldn’t measure and use data, it means that it shouldn’t always  be mandated for a population. The recent wearable studies bear that out.
Apple Watch Nike Plus Series 2 Review 1220
Heart rate during strength training workout called “Fishing” (keeping it humorous for the social network) Apple Watch Nike Plus Series 2 Review 1220 (View on
Apple Watch Nike Plus Series 2 Review 101
Heart rate over the course of a day – workout in the morning. Great. But so what. (Note: This tracing does not measure variability) Apple Watch Nike Plus Series 2 Review 101 (View on

I’ll write a review of what I learned about HRV in more detail in a future post.

Some next frontiers

  • Watch could develop more into a computer. Imagine Siri becoming functional and apps evolving that provide non-health data to help make decisions. One of the features I love, by the way, is time travel. It’s turned off by default so turn it on (in the Clock setting on your phone) and it allows a quick look at weather in the immediate future. Something a computer is good at.
  • Watch as a research tool or clinical care tool. There’s this recent study on this and again, suffering from the 10% problem, but this was in a voluntary sample. I am not a researcher so I look forward to seeing what the possibilities are.


Comparing this to the beginning of the journey (Google Glass) this is a good evolution and I feel Apple is proceeding well on a path in an uncertain space around wearables.

The device is actually a good watch, with some computing, with some fitness, a nice integrated package. I think that works better for a population and allows growth of functionality than a device aimed at the 10% who persist in tracking after 12 months.
Here’s a list of the HRV papers I reviewed. Happy to dialogue with others on their thoughts on the future of this measurement.

Also, a gallery of the OOB (out of box experience) which is often the best part of a new anything.

Heart Rate Variability

papers and articles (feel free to suggest others)

The OOB Experience (link to gallery at

Apple Watch Nike Plus Series 2 Review_-4
You’re welcome. Apple Watch Nike Plus Series 2 Review_-4 (View on


I’m watching all of this with interest, not sure what to think or say about my own experience. I’m one of what you call the 10% … but how did that happen?? I have NEVER been athletic in any way ever, until I took the YMCA / CDC Diabetes Prevention Program in 2015 and became an altered being. How did that happen?

This doesn’t deny anything you’ve said, of course. Your posts methodically document what usually happens. I’m hoping someone will methodically document how to replicate what happened with me. A separate, not contradictory, question.

Watching, learning.

Hey Dave,

There’s nothing wrong with being unique/diverse and sometimes who you are and what you do can be replicated. Sometimes it can’t. Always important to remember the mantra “The User is Not Like me,” especially when thinking about a group of people and their health needs 🙂 .


Ted Eytan, MD