Sleep Cycles

Flipping through the top selling apps on the iPhone, I ran across an app named “Sleep Cycle”. I checked it out. This app uses the phone’s accelerometer (motion-sensor) to monitor the degree of movement while you sleep. You set an alarm time and, based on what stage of sleep you are in, it will wake you within 30 minutes of that alarm. The idea is you aren’t woken during a deep stage of sleep.

As a physiology instructor, I was interested to see how well this app worked and how much of it was just novelty. So if you’ll indulge me, let me speak briefly about sleep cycles.

We alternate between “non-rapid eye movement” (NREM) and “rapid eye movement” (REM) sleep during the night. For the typical person, it takes about 45 minutes to slip through the first two stages of NREM and into the latter two, when true deep sleep occurs. (Incidentally, nightmares tend to occur in the latter two stages of NREM.) After about 90 minutes, brain activity changes dramatically, our muscles become inhibited, and our eyes start flicking around (thus the name of the sleep). Most dreaming occurs in REM; the muscle paralysis keeps us from acting out our dreams, even though the eyes are following what is being seen. The brain activity is “more awake” during REM than when we are actually awake. The typical adult will re-enter REM about every 90 minutes; each time, REM lasts a little longer. NREM is thought to help physiological processes “reboot” (if you will), while REM is thought to work through psychological needs.

So in trying this app out, the graph is a little misleading. Since no motion occurs during REM sleep, the part of the graph that says “dreaming” is a misnomer. Perhaps a better term would be “wakefulness”. However, “deep sleep” works okay for the lower portion, but keep in mind that REM is when we are dreaming the most, and true “deep sleep” occurs in the latter two stages of NREM. More motion likely means you are not in REM, but for deep sleep you could easily be moving or not. Being woken from deep sleep is what makes for the groggy feeling, so motion is not the best indicator. The app builds on ideas that actigraphy utilizes–where sleep technologist monitor motion–but should be used for novelty purposes only and to get a GENERAL idea of how you tend to sleep. The fact is, you could lay still during NREM just as you do in REM, so motion is not a true test of sleep cycling; only a brain monitor can do that. However, if you are really having sleep issues, a true sleep study is the way to go.

My first night with the app did show fairly consistent time frames for the typical sleeper that I described above. I entered a state of no-motion (which is REM) about every 90 minutes. I apparently had two such stages during my 7 hours of sleep, which by the way is arguably not enough cycles through REM, and the second was longer than the first. (I started to enter a third, but about that time my pet woke me up. Ha ha.)

Sleep Cycles

2010 Winter Olympics

If you are as big a fan of the Olympics as me, you’ll find yourself glued to the TV for the next two weeks. Well that may not be so easy, so I went searching for a complete TV schedule and found this. Maybe it’ll help you pick out what and when to watch. TIMES ARE IN EASTERN.

NBC Universal’s 2010 Winter Olympics Schedule
This is the NBC Universal Olympics Schedule from Day 1, February 12 until Day 17 on February 28. I have omitted overnight programming on MSNBC which starts at 3 a.m.

DAY 1 – FRIDAY, FEBRUARY 12
NBC, 7:30 p.m. – midnight: Opening Ceremony, Ski Jumping: Qualification

DAY 2 – SATURDAY, FEBRUARY 13
NBC, 2 p.m. – 6 p.m.: Ski Jumping: normal hill, Speed Skating: men’s 5000m and Biathlon: women’s sprint.
CNBC, 3 p.m. – 5:30 p.m.: Women’s Hockey: Sweden vs. Switzerland
CNBC, 8 p.m. – 10:30 p.m.: Women’s Hockey: Canada vs. Slovakia
NBC, 8 p.m. – 11:30 p.m.: Short Track: men’s 1500m (live ET/CT). Alpine Skiing: men’s downhill — and women’s moguls.
NBC, midnight – 1 a.m.: Luge: Men’s Singles, Women’s Short Track prelims: 500m, relay and medal ceremonies.

DAY 3 – SUNDAY, FEBRUARY 14
NBC, 1 p.m. – 6 p.m.: Nordic Combined (live ET/CT), Speed Skating, Luge and Biathlon.
USA, 3 p.m. – 5:30 p.m.: Women’s Hockey: USA vs. China
NBC, 7 p.m. – 11 p.m.: Alpine Skiing: Women’s Combined. Figure Skating: Pairs Short Program. Luge: Men’s Singles Gold Medal Final
NBC, 11:35 p.m. – 12:05 a.m.: Recap and analysis from Figure Skating’s opening act: the pairs short program. Plus, medal ceremonies from Speed Skating and more.

DAY 4 – MONDAY, FEBRUARY 15
NBC, 1 p.m. – 5 p.m.: Women’s Cross Country, Men’s Snowboarding and Men’s Cross Country
MSNBC, 5:30 p.m. – 8 p.m.: Women’s Hockey: Canada vs. Switzerland
NBC, 8 p.m. – midnight: Figure Skating: Pairs Free Skate, Snowboarding: Men’s SBX, Speed Skating: Men’s 500 meters
NBC, 12:35 a.m. – 2 a.m.: Women’s luge, Medal ceremonies

DAY 5 – TUESDAY, FEBRUARY 16
USA, noon – 3 p.m.: Men’s Curling: USA vs. Germany
NBC, 3 p.m. – 5 p.m.: Biathlon: men’s 12.5K, women’s 10K
USA, 3 p.m. – 5:30 p.m.: Men’s Hockey: USA vs. Switzerland
CNBC, 5 p.m. – 8 p.m.: Women’s Curling: USA vs. Japan
MSNBC, 5:30 p.m. – 8 p.m.: Women’s Hockey: USA vs. Russia
CNBC, 8 p.m. – 10 p.m.: Men’s Hockey: Canada vs. Norway
NBC, 8 p.m. – midnight: Figure Skating: men’s short program, Snowboarding, Speed Skating: Women’s 500 meters
CNBC, 10 p.m. – 12:30 a.m.: Women’s Hockey: Finland vs. China
CNBC, 12:30 a.m. – 2:30 a.m.: Men’s Hockey: Russia vs. Latvia
NBC, 12:35 a.m. – 2 a.m.: Women’s Luge

DAY 6 – WEDNESDAY, FEBRUARY 17
USA, noon – 3 p.m.: Women’s Curling: USA vs. Germany
NBC, 3 p.m. – 5 p.m.: Women’s Cross Country Skiing
MSNBC, 3 p.m. – 5:30 p.m.: Men’s Hockey: Finland vs. Belarus
CNBC, 5 p.m. – 8 p.m.: Men’s Curling: USA vs. Switzerland
MSNBC, 5:30 p.m. – 8 p.m.: Women’s Hockey: Canada vs. Sweden
CNBC, 8 p.m. – 10 p.m.: Men’s Hockey: Sweden vs. Germany
NBC, 8 p.m. – 11:30 p.m.: Speed Skating: men’s 1,000 meters, Alpine Skiing: women’s downhill, Snowboarding: men’s halfpipe, Short Track: men’s 5,000 meter relay & 1,000 meters.
CNBC, 10 p.m. – 12:30 a.m.: Women’s Hockey: Switzerland vs. Slovakia
NBC, 12:05 a.m. – 1:30 a.m.: Short Track: men’s 1,000 meters, doubles luge, medal ceremonies.
CNBC, 12:30 a.m. – 2:30 a.m.: Men’s Hockey: Czech Republic vs. Slovakia

DAY 7 – THURSDAY, FEBRUARY 18
USA, noon – 3 p.m.: Men’s Curling: USA vs. Denmark
NBC, 3 p.m. – 5 p.m.: Women’s Biathlon: 15K, Women’s Snowboarding: Halfpipe
USA, 3 p.m. – 5:30 p.m.: Men’s Hockey: USA vs. Norway
CNBC, 5 p.m. – 8 p.m.: Women’s Curling: USA vs. Denmark
MSNBC, 5:30 p.m. – 8 p.m.: Women’s Hockey: USA vs. Finland
CNBC, 8 p.m. – 10 p.m.: Men’s Hockey: Canada vs. Norway
NBC, 8 p.m. – midnight: Figure Skating: Men’s Free Skate, Women’s Snowboarding, Speed Skating: women’s 1,000 meters
CNBC, 10 p.m. – 12:30 a.m.: Women’s Hockey: Russia vs. China
CNBC, 12:30 a.m. – 2:30 a.m.: Men’s Hockey: Russia vs. Slovakia
NBC, 12:35 a.m. – 2 a.m.: Skeleton: Men’s and women’s 1st and 2nd runs, Biathlon: men’s 20K, medal ceremonies.

DAY 8 – FRIDAY, FEBRUARY 19
USA, noon – 3 p.m.: Women’s Curling: USA vs. Russia
MSNBC, 3 p.m. – 5:30 p.m.: Men’s Hockey: Sweden vs. Belarus
NBC, 3 p.m. – 5 p.m.: Women’s Cross Country Skiing
CNBC, 5 p.m. – 8 p.m.: Men’s Curling: USA vs. France
CNBC, 8 p.m. – 10 p.m.: Men’s Hockey: Czech Republic vs. Latvia
NBC, 8 p.m. – 11:30 p.m.: Figure Skating: Ice Dancing, Women’s Skeleton
CNBC, 10 p.m. – 1 a.m.: Women’s Curling: Canada vs. Denmark
MSNBC, midnight – 3 a.m.: Men’s Hockey: Finland vs. Germany
NBC, 12:05 a.m. – 1:30 a.m.: Medal ceremonies

DAY 9 – SATURDAY, FEBRUARY 20
MSNBC, noon – 3 p.m.: Men’s Curling: USA vs. Sweden
NBC, 1 p.m. – 6 p.m.: Freestyle Skiing: Women’s, Ski Jumping: Large Hill, Cross Country Skiing: Men’s 30K Pursuit
MSNBC, 3 p.m. – 5:30 p.m.: Men’s Hockey: Norway vs. Switzerland
CNBC, 5 p.m. – 8 p.m.: Women’s Curling: USA vs. Great Britain
MSNBC, 7:30 p.m. – 10 p.m.: Men’s Hockey: Slovakia vs. Latvia
NBC, 8 p.m. – 11:30 p.m.: Alpine Skiing: Women’s Super G, Bobsled: Two man, Short Track: men’s
CNBC, 10 p.m. – 1 a.m.: Men’s Curling: Canada vs. Great Britain
MSNBC, midnight – 3 a.m.: Men’s Hockey: Belarus vs. Germany
NBC, midnight – 1 a.m.: Short Track: Women’s 1,500 meters and medal ceremonies.

DAY 10 – SUNDAY, FEBRUARY 21
MSNBC, noon – 3 p.m.: Women’s Curling: USA vs. Canada
NBC, noon – 6 p.m.: Freestyle Skiing: Ski Cross, Biathlon: Men’s 15K, Men’s Hockey: Czech Republic vs. Russia
CNBC, 5 p.m. – 8 p.m.: Men’s Curling: USA vs. Great Britain
MSNBC, 7 p.m. – 10 p.m: Men’s Hockey: USA vs. Canada
NBC, 7 p.m. – 11 p.m.: Figure Skating: Ice Dancing (Original Dance), Alpine Skiing: Men’s Giant Slalom
CNBC, 10 p.m. – 1 a.m.: Women’s Curling: USA vs. Sweden
NBC, 11:35 p.m. – 12:30 a.m.: Biathlon: Women’s 12.5K, Medal Ceremonies
MSNBC, midnight – 3 a.m.: Men’s Hockey: Sweden vs. Finland

DAY 11 – MONDAY, FEBRUARY 22
USA, noon – 3 p.m: Men’s Curling: USA vs. Canada
NBC, 3 p.m. – 5 p.m.: Cross Country Skiing: Men’s and Women’s team sprints
USA, 3 p.m – 6 p.m.: Women’s Hockey: Semifinals
CNBC, 5 p.m. – 8 p.m.: Women’s Curling: Canada vs. Sweden
CNBC, 8 p.m. – 10:30 p.m.: Women’s Hockey: Semifinals
NBC, 8 p.m. – midnight: Figure Skating: Ice Dancing (Free Skate), Freestyle Skiing, Ski Jumping
CNBC, 10:30 – 1 a.m.: Men’s Curling: USA vs. China
NBC, 12:35 a.m. – 2 a.m.; Men’s Hockey: Elimination Round, Medal Ceremonies

DAY 12 – TUESDAY, FEBRUARY 23
USA, noon – 3 p.m.: Women’s Curling: USA vs. China
NBC, 3 p.m. – 5 p.m.: Biathlon: Women’s 4 x 6K Relay, Speed Skating: Men’s 10,000 meters
USA, 3 p.m. – 6 p.m.: Men’s Hockey: Elimination Round
CNBC, 5 p.m – 8 p.m.: Men’s Curling: Canada vs. China
CNBC, 8 p.m. – 10 p.m.: Men’s Hockey: Elimination Round
NBC, 8 p.m. – midnight: Figure Skating: women’s short program, Freestyle Skiing: Women’s Ski Cross Final, Bobsled: Women’s, Alpine Skiing: Nordic Combined
CNBC, 10 p.m. – 12:30 a.m.: Men’s Hockey: Elimination Round
MSNBC, 10 p.m. – 1 a.m.: Women’s Curling: USA vs. Switzerland
CNBC, 12:30 a.m. – 2:30 a.m.: Men’s Hockey: Elimination Round
NBC, 12:35 a.m. – 2 a.m.: Figure Skating recap plus medal ceremonies

DAY 13 – WEDNESDAY, FEBRUARY 24
NBC, 3 p.m. – 5 p.m.: Men’s Hockey: Quarterfinal Round
MSNBC, 5 p.m. – 8 p.m.: Curling: Tiebreaker Round
CNBC, 7 p.m. – 10 p.m.: Men’s Hockey: Quarterfinal Round
NBC, 8 p.m. – 11:30 p.m.: Alpine Skiing: Women’s Giant Slalom, Bobsled, Short Track Speed Skating: Men’s 500 meters and Women’s 3,000 meters relay
CNBC, 10 p.m. – 12:30 a.m.: Men’s Hockey: Quarterfinal Round
NBC, 12:05 a.m. – 1:30 a.m.: Short Track Speed Skating: Women’s 1,000 meters and Medal Ceremonies
CNBC, 12:30 a.m. – 2:30 a.m.: Men’s Hockey: Quarterfinal Round

DAY 14 – THURSDAY, FEBRUARY 25
USA, noon – 3 p.m.: Women’s Curling: Semifinal
MSNBC, 2 p.m. – 4:30 p.m.: Women’s Hockey: Bronze Medal Game
NBC, 3 p.m. – 5 p.m.: Cross Country Skiing: Women’s 4 x 5K relay
CNBC, 5 p.m. – 8 p.m.: Men’s Curling: Semifinal
MSNBC, 6 p.m. – 9 p.m.: Women’s Hockey: Gold Medal Game
NBC, 8 p.m. – midnight: Figure Skating: Women’s Free Skate, Freestyle Skiing
NBC, 12:35 a.m. – 2 a.m.: Figure Skating wrap up plus Medal Ceremonies

DAY 15 – FRIDAY, FEBRUARY 26
USA, noon – 3 p.m.: Women’s Curling: Bronze Medal Match
NBC, 3 p.m. – 5 p.m.: Men’s Hockey: Semifinal
MSNBC, 3:30 p.m. – 5:30 p.m.: Speed Skating: Men’s and Women’s Pursuit
CNBC, 6 p.m. – 9 p.m.: Women’s Curling: Gold Medal Match
NBC, 8 p.m. – 11:30 p.m.: Alpine Skiing: Women’s Slalom, Short Track Speed Skating: Men’s and Women’s 1,000 meters
CNBC, 9 p.m. – midnight: Men’s Hockey: Semifinal
NBC, 12:05 a.m. – 1:30 a.m.: Snowboarding: Women’s PGS Gold Medal Final plus Medal Ceremonies

DAY 16 – SATURDAY, FEBRUARY 27
USA, noon – 3 p.m.: Men’s Curling: Bronze Medal Match
NBC, 1 p.m. – 6 p.m.: Snowboarding: Men’s PGS Gold Medal Final, Speed Skating: Pursuit
CNBC, 6 p.m. – 9 p.m.: Men’s Curling: Gold Medal Match
NBC, 8 p.m. – 11 p.m.: Alpine Skiing: Men’s Slalom, Bobsled: Four Man, Figure Skating: Champions Gala, Snowboarding: Men’s Parallel
MSNBC, 10 p.m. – 12:30 a.m.: Men’s Hockey: Bronze Medal Game

DAY 17 – SUNDAY, FEBRUARY 28
MSNBC, 6 a.m. – noon – Figure Skating: Champions Gala
NBC, noon – 3 p.m.: Cross Country Skiing
NBC, 3 p.m. – 6 p.m.: Men’s Hockey: Gold Medal Game
NBC, 7 p.m. – 11 p.m.: Closing Ceremony
NBC, 11:35 p.m. – 12:35 a.m.: Wrap Up

2010 Winter Olympics