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Jun

Activity/Fitness Monitor Showdown

OK, I admit it. I’m a data junkie. I just totally believe that you can’t improve what you can’t measure. So, I want to measure everything. Although, it’s even better when someone or something does the measuring for me. With this in mind, I recently decided to figure out what was the best way to measure my physical activity – movement, calories, weight lifted, stairs climbed, etc. Unfortunately, some of this data remains hard to come by. While machines in the gym – treadmill, elliptical, stationary cycle, etc. all generate some types of data. This data isn’t normalized across machines and, generally, cannot be exported for tracking.

The answer seemed to lie in the new crop of activity monitors available. The small devices worn on the wrist or kept in the pocket to track the steps one has taken, the calories burned, elevation climbed and so forth. Unfortunately, the current crop of activity monitors don’t really even try to cover some of the data I was looking for. Even worse, I had heard that many of the facets of activity they claim to cover are not all that accurate. Since my interest in gathering activity data was bordering on a need rather than desire, I had to find out what my options were. So I tried several trackers out.

My pseudo-scientific test included most of today’s popular devices plus one monitor that runs on my Android phone (there are other Android apps and, of course, iOS apps as well, especially for Apple phones with the M7 processor).

Withings Pulse
Fitbit Flex (thanks Brad Feld)
Garmin Vivofit
Jawbone UP (thanks Shawn Broderick)
Moves App

There are several more, of course, but my arms are short. I wore these devices daily for about a month. It was still cold outside so I could hide this embarrassing electronic armband with the sleeves of a shirt. There are lots of features of these devices that I don’t cover here. If you’re going to make a purchase, you should hit the companies’ web sites for complete information.

I need to note that I didn’t test all types of activities that these monitors track. Since these devices are for the arm or pocket, cycling isn’t accurately tracked (nor is it claimed to be) and I am not a runner, so I didn’t even test for running. I also didn’t test the sleep functions of any of the trackers. I move around a reasonable amount each day, I frequently spend time on an elliptical trainer and in the gym lifting weights or doing body-weight exercises. I am a reasonably fit and active person. The question is, would the data reflect this.

Let me get right to the bottom line: These devices measure some activities moderately well and others either poorly or not at all. They all greatly depend on a certain type of body movement that their accelerometers (motion detectors) can pick up. A person who has a hard-pounding walking style will register more activity than one who floats over pavement, for example. If your primary activities are non-aerobic (weight lifting), these devices are useless. And even if they are aerobic, but only involve smooth movements (e.g. cycling), very little data is acquired. They are, basically, walking and running monitors. Additionally, the data gathered is best used as a comparison of the user’s activity over time because the absolute accuracy of these devices is questionable.

Here are a couple of examples that bear this out . . .

The reports below are generated by each of the devices. The first three – by the Garmin, Withings (side-by-side) and Fitbit (below), respectively – are clips from their web pages. Unfortunately, the next two – from Moves and Jawbone – don’t provide a graphical web interface. The data is only available on a computer by downloading it into a spreadsheet via the web. All the devices have phone apps that display the data graphically. While it’s nice to be able to access the data on a phone, I much prefer being able to see and manipulate the data with a computer on the web. Personal preference.

This is the data from May 10 – a randomly chosen day (I did the test on the elliptical 14 times during the month). All devices were worn throughout the day. You can see that the data on number of steps varies wildly.

Device	Steps
Garmin	4,218
Withings	9,715
Fitbit	4,548
Moves	8,786
Jawbone	7,059

All reported correctly that the primary movement started at about 7:30 pm and lasted for about an hour. During that time I was on an elliptical machine which can very accurately track the number of steps taken. The elliptical reported, roughly, 6,500 steps were taken, making the reported values of less than 5,000 for the whole day a bit suspect.

The distance covered also varies a lot between devices. It ranges from 2.09 mi (Fitbit) to 4.19 miles (Withings). Regardless of what distance I actually traveled during the day, the 2x difference in range makes me question all of the data. FWIW, the elliptical claims I ran/climbed more than 6 miles during that session.

On another day, I did a similar test on the elliptical with all devices in my pocket instead of on my wrist. The results were different – all values were higher, but the variance was just as high.

The data from April 21 is below in the same order as previously reported. Unfortunately, there is no Jawbone data for this day. This was a moderately active day with a concentrated weight lifting session from 2:30-3:30 pm. Note that none of the apps register much activity during this time. For most of the day, I was just moving around, doing whatever I needed and wanted to do without actually “exercising.” For this, most of the trackers were more aligned, however, there is still almost a 2x difference between the lowest (Moves) and highest (Garmin) in step count.

Clearly, the lack of activity reported during a very active weight lifting session shows that these trackers are not a reliable way of tracking this type of activity data.

Some thoughts about each of the trackers . . .

Withings Pulse:

Pros –

Device fits in pocket nicely or on the wrist with a watch-like band
Great display of all data, scrollable to see results from other days
Touch sensitive screen for scrolling through data
Micro-USB port on device for charging (this is a pro because as an Android user, I always have a micro-USB charger with me)

Cons –

Hard to read display in sunlight
Not water resistant

Garmin Vivofit

Pros –

Replaceable battery lasts for a year (others need recharging after 10-14 days)
Bright display easily readable in sunlight
Red reminder indicator to get your ass off the couch
Water resistant
Data is combined with that from other Garmin devices to give a bigger activity picture

Cons –

Bluetooth syncing failed frequently
Web site is difficult to negotiate

Fitbit Flex

Pros –

Small, easily moves from wrist band to pocket
Water resistant

Cons –

No data display – just some LEDs showing progress towards the day’s goals
I found the wrist band hard to put on even after a couple of month’s usage
Requires USB dongle for recharging

Moves

Pros –

Runs on phone so has optional access to GPS data – knows how fast your moving and where you are
Runs on phone so it’s almost always with you

Cons –

Runs on phone so it consumes battery power
No graphical data available on the web

Jawbone UP

Pros –

Looks the most like jewelry
Water resistant

Cons –

No data display – just a colored light to tell you when you’ve achieved your goal
No graphical data on the web
No wireless communication – must connect to computer to download data (newer version of hardware apparently has Bluetooth)
Requires USB dongle for recharging

Where do I go from here . . .

None of these devices are perfect or, for that matter, even very good in an absolute sense. As I said earlier, they do a decent job indicating your relative activity from day to day and in that way, they can disclose and track some valuable metrics. Many of these devices have other features that may increase their value to the user as well. The Withings Pulse can also track your pulse and blood oxygen levels and the Garmin Vivofit always shows the current time, for example.

For me, I think I’m going to move to a combination of devices. Perhaps Moves on my phone because it’s so transparent for daily activity (I’m carrying it anyway) and either the Garmin Vivofit or Withings Pulse for when I’m purposefully exercising. I’m then going to use the HumanAPI to combine the data so that I can track my overall activity in one place. Or, perhaps I’ll get some help with my OCD-ish need for collecting data and drop the whole thing altogether.

June 1st, 2014

Will

5 Comments

Mar

Knee Surgery . . . Finally

After whining about a deteriorating knee that has slowly eroded my capability to ride my bike over the last few years, I finally found a sports medicine physician who diagnosed my problem and performed surgery to fix it. I had the surgery yesterday and start my too long recovery period today. Officially, the diagnoses was Chondromaliacia Patellae caused by Patellar Tilt (see diagram at right).

It turns out that amount of cycling I was doing caused the patella (kneecap) to be pulled laterally towards the outside of the knee. Basically, my lone focus on cycling caused certain muscles to develop while others remained weak, pulling things in one direction only. Since the patella was pulled outside the groove it normally sits in, it rubbed the cartilage between the kneecap and femur where it’s not designed to – over the sharper part of the femur. After about 10 million cycles, it rubbed right through so that there is no longer any cushion between the kneecap and femur. Bone rubs on bone. Ouch.

Funny, though, I had no trouble walking. The hole was low on the knee so it only affected me when I bent it by over about 30 degrees. Stairs were hard, ladders were almost impossible and cycling . . . well I had to stop riding last August.

The surgery is arthroscopic and isn’t major, relatively speaking. The surgeon cleans up the crappy hole in the cartilage and does a lateral release – cutting part of the connective tissue that holds the kneecap in place (the lateral retinaculum) allowing it to slide into its normal resting place. Finally, and this is the gross part, the surgeon drills or digs a small hole in the femur (a process called microfracturing) to release cells that help the cartilage heal more completely.

About four weeks after surgery, I’ll be getting four weekly injections of Orthovisc, which is made from naturally occurring lubricants found in joints. Apparently, this is injected with a needle the size of an oil well drill bit, but it’s worth manning up because it helps the cartilage heal, adds some lubrication to the beaten up joint and speeds up all-around recovery a good deal.

The prognosis is that it will take me about 4 months to recover enough to get back on my bike for any serious riding – why didn’t I do this in September? One of the advantages in working with a sports medicine specialist is that they are very sensitive to their patient’s addiction to their activities and work to get them back in action faster. Given that, I’m hoping my doc works with me to cut some time off the textbook recovery period.

Update(s): when I searched the web for information about this surgery and, more importantly, the recovery from it, there was very little to be found. So, for those of you have stumbled across this as a result of a search for information, I’m going to keep a brief digest of what my recovery was like. As usual, your mileage may vary.

One day after surgery – Ouch! Anesthesia and anesthetic are all gone and being very much missed. Like an idiot, I didn’t take the pain medicine (percocet, in my case) soon enough or frequently enough. This is the only day I had to take any though. 24 hours after surgery, the pain was manageable. I’m a wimp, too.
Two days after surgery – Still a lot of swelling and very stiff. Moving around on crutches a bit. Started using a CPM machine to exercise the knee. Doesn’t seem like it would help, but it does. Start doing basic exercises with short range of motion. Painful.
One week after surgery – I still can’t bend my leg much. After using crutches for about 4 days, I moved onto a cane. Doctor says I don’t need it, nurse and physical therapist insist I do. So, I compromise. I overuse it and the knee remains really swollen. Sleeping is hard, every move causes me to wake up.
Ten days after surgery – See the surgeon. Have the stitches removed (no bleeding at any time – the holes are very small). He says my knee is abnormally swollen. I probably used it too much. Gave me a few more exercises and tells me that I can do the PT work myself if I like, which I do. He tells me “full” recovery will take 4-6 months. Longer than his original estimate. I start walking without any support (cane/crutches) all the time. I crank the CPM machine to 80-degrees of motion.
Two weeks after surgery – Still discouragingly stiff and swollen. Doing loads of basic leg lifts and such and spending >2hrs/day in the CPM machine. I’m getting around better and can even climb (not descend) stairs a little. Interesting how the basic act of releasing my leg in the backswing of a stride is stiff and painful. I can walk, but with a stiff leg. Sleeping remains difficult since I toss and turn, waking up each time.
Three weeks after surgery – Remains stiff and swollen. The swelling is certainly less severe than right after surgery, although it’s hard to tell if it’s better than a week ago. Spending >2hrs/day in the CPM machine and another hour/day “exercising” and icing. Also, added a 20 minute session/day on the elliptical – almost no resistance. Like last week, releasing my leg on the backswing of my stride is stiff and painful. Getting little sleep because every toss and turn wakes me up with some pain.
Four weeks after surgery – I could feel enough improvement that I abused it. I ended up standing and walking a lot this week. At times, I could walk with almost no limp, but ended up paying for that in the last couple of days. No real pain, just a bit stiff on the backswing of the leg, I can go up small flights of stairs with almost no pain, but can only go down stairs one at a time – always leading with my bad leg. Still using the CPM machine, now at 100-degrees and I’ve turned up the resistance on the elliptical, although not the time. Sleeping is no longer a huge problem, although I still end up waking up because I bump or twist something during the night.
Five weeks after surgery – I still have a lump on the outside of my knee that is completely numb to the touch, but doesn’t disturb me otherwise. I think this is swelling around where the muscle holding the patella was cut. That’s also where I feel the tightness in the backswing of my leg, which continues. Once I get loose, I can walk without much of a limp. Climbing stairs has gotten a bot easier and I can even gingerly descend stairs with both legs. I’ve increased both my time and resistance on the elliptical and have even gone for a couple of mile walk. The knee makes a lot of crunchy noises, though, which is freaking me out a bit.
Nine weeks after surgery – Fast forward . . . another appointment with the surgeon, only my second one since the surgery. He’s pretty casual. I called a couple of weeks ago because of the crunching sounds coming from my knee when I bent it. He said, “nothing to worry about.” That didn’t help. They did, however, mostly go away over the following weeks. I still have the tightness where the band was cut, although it’s not as bad. I stopped using the CPM machine at the 6-week mark, per doctor’s orders. I don’t think it was doing too much for me anyway. Going up many stairs brings about a little pain. If I hadn’t had surgery, it might not even register too much. Going downstairs is quite a bit different, although I can do it much better and with less pain than just a couple of weeks ago. At this visit to the doctor, he told me to start physical therapy, which I will this week. He told me it will be another four weeks until I should even sit on a bike. I’ve upped both time and resistance on the elliptical and am on it five times per week. I’ve also restarted weight training – upper body only, of course. Things are getting better, although much more slowly than forecasted by me or the surgeon. My biggest concern is that there is no indication yet that the surgery actually fixed the original problem. There are other pains and stiffness that mask the pain from the injury.
Sixteen weeks after surgery – well, I’ve officially blown off the cycling season, there’s no way I can ride a bike . . . at all. Things are better, I guess, but they’re not very good. Stairs remain a problem, especially down. I’ve been doing physical therapy now for almost 6 full weeks. I’m stronger, for sure, but not in much less pain. The pain is different most of the time and I still feel a lot of numbness on the outside of my knee – the other side from the injury. I have to think it’s surgically related. Probably from the band that was cut holding down the patella. Stretching like a maniac helps, but disappointingly little. I can’t squat down and if I do work my way to the floor, I can’t get up. While supporting my weight, even half of it, I can’t bend my knee more than about 50-degrees. Without weight, I can bend it all the way. Very discouraging.

March 5th, 2011

Will

13 Comments

Feb

Gadget Review – Fitbit

Image via CrunchBase

What’s a FitBit? It’s a tiny device that you clip to your clothing or carry in your pocket that measures the number of steps you take (really, the movement of your torso), and estimates the number of calories you burn during the day. When plugged into its little base station which is connected to your computer, the data is uploaded to a web site for storage, display, comparison and to be combined with manually entered data about your non-measured activities and what you ate. It only costs $99 and is an incredibly nice piece of engineering and packaging. While the company has sold a load of them, it seems that the early adopters are, not surprisingly, geeks, data junkies and fitness-o-philes. I think I may reside in all three camps and as such, was a relatively early adopter.

I’ve been carrying a FitBit with me for the last 8 months. It is so small and light and the battery lasts so long, that I often forget I have it with me (as I did this week when I went through one of those airport x-ray vision machines used to see if you’ve recently changed your underwear with it on me). Usually, I’m disappointed in the calorie consumption it reports at the end of the day through it’s small display, but that’s the point. It kicks me in the ass so I do less sitting on it. It’s not a FitBit issue, it’s a personal one.

As with many such measuring devices, the absolute data is less important than the relative data. If I consistently burn 2,500 calories per day, I know that a lard-retaining 1,900 calories expended in a day is going to get me in trouble. Especially if I have several of those back-to-back.

When I ordered my FitBit, it was DOA. Well, it wasn’t entirely dead, there was a bunch of garbage on the little on-board display. Resetting (by sticking a paperclip into the tiny hole in the bottom of the base station, FWIW) didn’t help. I sent an email to support which, after sending me a long email asking me to try everything I had already tried, RMA’d the device and sent me a new one. Pretty easy and the right way of doing it.

The only downside to the device is in what it can’t do – measure the activity that doesn’t involve moving my torso. You can do bench presses all day long and register nothing north of the number of calories you would be burning if sleeping. What I’m really waiting for is something that does real time blood testing and can capture all muscle movement and extent. Non-invasively, of course. Until then, though, the FitBit tells me an awful lot about what I’ve been doing and sets the stage for thinking more about healthy living.

February 25th, 2011

Will

Health and Fitness

5 Comments