Sleep & body.

Sleep score

Each night gets a score out of 100 from four parts: how long you slept, how you felt, how close you went to bed to your usual time, and how close you went to bed to your target bedtime.

85 and up is Excellent, 70–84 Good, 55–69 Fair and under 55 Poor. With an 8-hour goal, duration is worth 24 points at 5 hours, 32 at 6, 40 at 7 and the full 50 from 8 to 10 hours.

Sleep week and debt

Your sleep week covers the last 7 mornings you woke up. A night belongs to the day you woke, and if two sleeps end the same day, the longer one counts.

7-day average = mean hours of the nights logged
sleep debt    = Σ max(0, goal − hours)   (nights not logged add nothing)
consistency   = 100 − 1.1 × spread of bedtimes in minutes   (standard deviation, needs 3 nights)

Your sleep goal is 8 hours by default (7–10), with bedtime 10:30 PM and wake-up 6:30 AM. Insights unlock after 3 nights, such as how a tag like caffeine or a late meal changes your sleep.

Logging sleep and XP

• Tap Going to bed at night and I'm awake in the morning, log a night by hand, or let your watch or ring send it through Health Connect, with sleep stages.
• Health Connect nights from the last 14 days are read. Stretches of sleep less than an hour apart join into one night, and anything under 2 hours is skipped.

A logged night is also one of the things that keep your activity streak going, and some Trials ask for more sleep.

Readiness

Each morning Body › Today gives you a readiness score from last night's sleep, your resting heart rate and your training over the last two days.

readiness = 0.5 × sleep score + 0.3 × heart + 0.2 × training

heart    = 94 − 9 × (bpm above usual) + 2 × (bpm below usual)   (0 to 100)
training = 100 − 0.7 × (minutes in the last 48 h − 30)          (25 to 100)

If a part is missing, the others are averaged with their own weights. It needs sleep or resting heart rate; training alone gives no score. 75 and up is "Ready to go", 50–74 "Take it steady" and under 50 "Recover today".

Heart rate

• Your usual resting heart rate is the average of your readings from the 14 days before today. It needs at least 3.
• Today's reading is today's, or yesterday's if there's none yet. A reading you type in beats one from your watch.
• Labels: under 60 low (common in fit people), 60–80 typical, 81–100 the higher end, over 100 above the usual range.
• Heart rate zones use a maximum of 220 − your age (at least 140), in bands of 50–60, 60–70, 70–80, 80–90 and 90–100%.

Weight, BMI and body fat

• Weigh-ins come from you or from a smart scale through Health Connect, one a day. The chart's thick line is the average of your last 7 weigh-ins.
• Change compares today with your latest weigh-in at least 7 days ago, and at least 30 days ago.
• BMI = kg ÷ m². It's a rough guide: 18.5–24.9 is the usual healthy range, but it doesn't account for muscle.
• Body fat on the Weight card is always a real reading. When you have no reading from the last 60 days, your avatar's body uses an estimate instead:

body fat % = 1.2 × BMI + 0.23 × age − 10.8 × sex − 5.4
sex: 1 men · 0 women · kept between 6% (men) or 12% (women) and 55%

A 30-year-old woman at 5 ft 5 in and 140 lb has a BMI of 23.3 and an estimated 29.5%.

Goal weight

• Goal weights go with Lose weight (below your latest weigh-in) or Build muscle (above it). Maintain and Endurance have none.
• The goal has to be at least 2 lb (1 kg) away. A weight-loss goal can't go below a BMI of 18.5 for your height. A muscle goal can't be more than 20% above your current weight.
• Goal body fat has to be at least 1% below your latest reading, and no lower than 6% for men or 14% for women.

Body XP

Progress toward your goal pays in steps of 1 lb (or 0.5 kg), counted from your best weigh-in. Losing or gaining too fast pays half, because slow and steady wins.

toward your goal, healthy pace   +120
toward your goal, too fast       +60   (over 1% of your weight a week losing, 0.5% gaining)
moving away from your goal       −60   (won back when you return)

When you reach your goal weight, your goal switches to Maintain. Keep losing or Keep building puts the old goal back.

Health Connect

Levelwell only reads, and never writes, these seven types: