MONDAY'S MOST CLICKED WORKOUT
The Norwegian 4x4
The cardio session in Monday's 2-hour week: 4 rounds of 4 hard minutes, with 3 easy minutes between.
It's past midnight. Work's done, the house is finally quiet, and you're getting into bed while everyone you know has been asleep for hours.
And every sleep article you read seems to assume you're up at 6am.
That's life for a reader who works until 2 or 3am and sleeps until 10am. Same times, every day. She asked us whether that schedule is hurting her, and it's today's main question.
Short answer: keeping the same times every day matters more than when you go to bed. The time still counts, though, so it helps to give your body clock a hand.
Below is what the research says, plus how to find a trainer who'll take you from rehab to real strength work. If you want more on the habits around sleep, our check out all the guides are in the library.
What The Research Actually Says
Most of us grew up hearing that late nights are bad for you. The research is a bit more interesting than that.
Keeping the same times counts for a lot. A study of 60,977 women and men in the journal Sleep used wrist trackers to see how consistent people's sleep was from one day to the next. Compared with the least regular fifth, everyone else had a 20 to 48% lower risk of dying over about 6 years. Regularity also predicted that risk better than how many hours people slept.
Going to bed late isn't completely off the hook. Researchers at Stanford tracked the bedtimes of 73,888 adults with wrist sensors. Late sleepers had more depression and anxiety (Psychiatry Research) and more diabetes, obesity and high blood pressure (European Journal of Internal Medicine), even after accounting for how regular their sleep was. That was true for night owls and early risers alike. Their suggestion is to be asleep before 1am if you can.
Habits explain some of it. A Finnish study that followed 23,854 adults for 37 years found evening types had a 9% higher risk of death, mostly because of smoking and alcohol. Non-smokers who drank lightly had no extra risk.
Light is your best tool. Your body clock resets every day from the light that hits your eyes, a bit like setting a watch each morning. In 88,905 adults who wore light sensors, in PNAS, people who got the most daylight had up to 34% lower risk of dying over 8 years. People with the brightest nights had up to 34% higher risk. So if you sleep late, bright mornings and properly dark nights are the parts you can actually control.
The Bottom Line
So, back to our reader. Keeping the same times matters most, and she's already doing it. Here's what we'd add, and it works for anyone who sleeps late.
Keep the same times every day. Bed and wake within about an hour of your usual time, weekends included. Your body clock runs on routine, so a steady schedule tells it when to wind down and when to wake up. It's also the habit the Sleep study linked most closely to a longer life.
Get outside soon after you wake. 10 to 15 minutes of daylight, within the first hour. Light is the biggest signal your body clock uses to reset each day, and in the PNAS study, people with the brightest days had up to 34% lower risk of dying.
Keep the night dark. Dim the lights when you get home, use blackout blinds, and charge your phone outside the bedroom. Light at night tells your brain it's still daytime and holds back melatonin, the hormone that makes you sleepy. In the same study, the brightest nights came with up to 34% higher risk.
One honest caveat: these are observational studies, and most of the people in them were in their 50s to 70s, so they show links rather than proof. If work sets your hours, a steady late routine is still a solid place to start, and the light habits are the easiest to change.
A daily reminder makes the morning light easier to stick with. Set it for just after you usually wake up.
One more of your questions
Another reader is seeing a physio for a tailbone problem and wants to start strength training. Every time she asks about it, she gets a vague answer. How does she find the right trainer?
A physio's main job is getting you out of pain, so the next step is often a different professional. Ask your physio for a short note on what to avoid and what to build on. Then look for a trainer with an accredited qualification who has worked with women after menopause. In the US, try ACSM's ProFinder or Find an ACE Pro. In the UK, there's the CIMSPA directory. In Australia, ESSA lists accredited exercise physiologists, who often work with people coming back from injury.
FROM OUR INSTAGRAM
The longevity habits you do before 9am
Monday's post: four morning habits, including a walk in morning light and a phone that charges in the kitchen.
Worth Your Time
Are you a night owl or an early bird? Hit reply and tell us. We read every one.
Friday Preview
On Friday, a reader who loves baking wants to know how to keep it in their life without giving up on their health goals. We've got the swaps that change a recipe the least.
Until Friday.
Longevity Daily / The Building Decades
P.S. If you do one thing today, set the daylight reminder for just after you wake. Set it now.