Sleep Hacking on the Rocks

Tuesday, October 18, 2011

Since my first night with Zeo, I've learned a few things. My first week of data was confusingly all over the place, until I realized that I probably had the headband too loose. I ended up discarding that data and starting over again, so I've only got two weeks worth of information so far. Still, it's enough to infer a few things.

First up, I'm learning a bit about the device itself. I think as an overall trend, it provides reliable information; however, it does seem to make the occasional mistake. A couple of times I've put on the headband and it's shown me in deep sleep within five minutes, which is unlikely unless I secretly have undiagnosed narcolepsy. Similarly, I'll sometimes wake up in the morning and it will show me in deep sleep for a period of time that I thought I was awake. These weird readings were intermittent, and it took me a while to figure out what was causing them.

Alcohol is supposed to reduce your amount of REM and deep sleep. However, Zeo's cause and effect graph shows me something apparently atypical:

That's right... apparently alcohol drastically increases my amount of deep sleep. My first thought was perhaps I just sleep longer after drinking, but another graph dispels that notion:

So, despite getting roughly the same amount of sleep with and without alcohol, I'm apparently spending a much higher percentage of time in deep sleep. Zeo's support centre says that deep sleep is "important for growth, restoring muscle and building immunity". Does this mean that I'd have stronger muscles and a better immune system if I got tanked every night? Somehow, this doesn't seem quite right. I'm more inclined to think that Zeo misinterprets my "drunk" brainwaves as "deep sleep", especially given the times I've been awake (and tipsy) and it's told me that I'm in deep sleep.

Does this mean that Zeo is completely inaccurate and useless for tracking trends associated with alcohol consumption? Not quite. The other portion of restorative sleep, the one stage that everyone's heard about, is REM. REM is when the crazy dreams happen, and it's also apparently responsible for organizing memory to better apply what you learn. Essentially, REM sleep is for mental improvement, and deep sleep is for physical. Now, let's look at what happens to my REM sleep when I drink:

Quite the opposite! I suppose it is possible that Zeo is misrecording REM sleep as deep when alcohol is involved, but I'd prefer to see it as a true negative impact. Certainly, my brain doesn't feel quite as limber and organized the next day after I've had a few, so perhaps there's something to these results. Then again, I can't say my muscles and immune system feel particularly improved either.

One thing I think I can accurately take from these results is that having 1-2 drinks has no statistically significant impact on my sleep quality. This is rather interesting, and something I will continue to pay attention to. It's possible that the results may level out over time, as there are far more nights of 1-2 drinks than there are 5+ (which, I believe, is a good thing!).

As an aside, I'm a dreaming machine. Without alcohol (or with only 1-2 drinks), I'm averaging 150 minutes, or about 38 minutes above average for 17-29 year old women. This makes sense to me, as I can't think of a night in the recent past that I haven't had memorable dreams. On the flip side, my deep sleep is a little bit below average for my age group, but not by much. In fact, for all my complaints about not sleeping well, I'm actually pretty average, since my schedule allows me to stay up as late as I need and then sleep in a fair bit. If I had to regularly get up early, I'm guessing my scores would drop significantly. One day, I will put that to the test, but not until I absolutely have to.

Sadly, I won't be able to collect the next 3 weeks of data... I'll be in Europe! Conferences are the best thing about grad student life. Or is it the flexible schedule?

MAF 2: Slowly Getting Faster!

Wednesday, October 12, 2011

4 weeks in to my low heartrate training, I did another Maximum Aerobic Fitness (MAF) test to figure out if all this slow jogging is actually doing anything. Despite my inconsistent schedule and up to a week between runs, my MAF pace definitely seems to be increasing.

The first time I did an MAF test was also the first time I tried to run at a heart rate of 149 bpm. While I reported 14:36 minutes per mile, I technically should have taken the average of my two mile test, which would be 14:39 per mile (every second counts, right?). That's extremely slow - a whole 9:10 minutes per kilometre, or an hour and a half 10K! I was a little unsure how I'd go about doing any kind of useful training at that pace, as it took forever to get any sort of reasonable distance. As a reminder, here's my previous MAF pace and heart rate plot:

First MAF Test

Fast forward 4 weeks to Thanksgiving weekend, and things are looking up. My average pace over a 3 mile run has come down to 13 minutes per mile, or 8:08 minutes per kilometre. A full minute faster, after only 60 kilometres of running and a couple of bike rides, is really quite encouraging. I finally feel like I'm actually running a little bit, as I'm definitely passing all the walkers on the path, but it's still an easy, comfortable pace that I feel I could sustain for quite some time.

Taking a look at the Garmin data gives me a few hints as to how this improvement is possible. As much as I'd like to think it's just development of my aerobic system, it seems like I'm just getting better at sticking to the right pace. During MAF 1, my average heart rate was only 146, suggesting that I erred on the side of caution when it came to staying below 149. MAF 2 has my average heart rate at 148 for each of my three 1-mile splits, so it seems that I'm getting better at being consistent and learning just how much I can push the threshold. You can also see from the graph below that I'm getting a bit better at maintaining a consistent pace, rather than speeding up and slowing down in response to a fluctuating heart rate.

Second MAF Test

With this apparent adaptation masquerading as improvement in aerobic fitness, I'm guessing that future MAF tests won't show quite such a dramatic improvement, and I've put up a little graph on the sidebar of this blog that will probably turn into a decaying exponential before long. However, I'm planning to stick with it, as it's fun and easy, and I can do it without coughing too hard. In fact, I'd like to declare a lofty goal:

By next summer, my MAF pace will be 6 minutes per kilometre (9:36 per mile).

"Will" is perhaps too strong of a word, but there it is, published on the interwebs for all to see. 6 minutes is about my maximum 10K pace, so if I could reach that at a nice easy 149 bpm heart rate, I'd be laughing. Now, all I need to do is make the time for enough running to bring about that kind of improvement.

The Douglas Fir Trail: Urban Dirt

Tuesday, October 4, 2011

Not far upstream from downtown Calgary, you'll find a tiny piece of modified nature called the Douglas Fir Trail. This 1.5 km chunk of dirt runs parallel to the pathway on the south side of the river, and provides a nice change of pace and scenery. It's no Grouse Grind, but at 2 km from my house, it has a certain appeal.

I haven't been posting much about low HR training, despite it being the ostensible reason I started this blog. Primarily, there really isn't much to say. I've done some runs, I've kept under my target heart rate, I still cough far too frequently. I believe I'm getting better at maintaining my slow pace, and I'm looking forward to doing my second MAF test to see if there's been any true improvement. However, I do have a secondary reason for not posting about running: I got yet another cold during the second week of this venture.

<rant>As my friend kindly pointed out the other week, for someone with a fairly healthy and active lifestyle, I tend to get sick a lot. I'm still haven't quite lost the cough from a summer of bronchitis, and I come down with a cold on top of it? It's not fair! I seem to get sick at least 4-5 times a year. I exercise, I try to get plenty of sleep, I eat lots of vegetables and whole grains, I don't dri-- well, maybe it's the drinking. </rant>

Rant aside, back to the Douglas Fir trail. Yes, it's only 1.5 km, but it's full of stairs, as I've tried to depict with my blurry cell phone photo. Trying to keep my heart rate below 149 makes this 1.5 km section take an embarrassing 20 minutes! You can see on the graph below where my pace starts spiking off the chart; I think my Garmin was reporting a few divide by zero errors as I slowly put one foot in front of the other to crawl up the stairs. The total elevation gain is rather pitiful, somewhere in the neighbourhood of 60 m, but it all happens at once so it ends up being a good workout - about the equivalent of walking up a 20 story building. I started trying to count stairs, but I'm not OCD enough and I lost count after around 170.

Each time I do this trail, I break the 149 heart rate rule a little bit more, and I think in the future I might give up on it entirely. Judging by the sweaty faces I see on the trail, I'm not the only one who gets out of breath, and it's much more fun to try to race up than it is to slowly plod. Besides, there's a nice spot at the top to take a break and admire the view:

All things considered, the Douglas Fir Trail is worth checking out if you're looking for some stairs, some softer footing, and a few minutes away from the city. According to the City of Calgary, there's even some 500-year old 2-metre diameter trees along this trail, though I've yet to see anything of the sort. Technically, the trail is 2.5 km long, but a portion of it is closed right now; perhaps that's where the big trees live.