8a.m. to 10a.m.
Weighing Oneself: “The best time of day to weigh yourself is first thing in the morning, immediately after getting out of bed,” said Prof. David Levitsky, nutrition. Stepping on the scale at this time after using the bathroom, but before eating breakfast can provide the most accurate reading of your weight.
“But don’t do it only once, but repeatedly over several days” Levitsky said. “Each weight will have error because of differences in body water content and GI content. If you take your weight over a period of at least a weight, you will see if you are gaining or losing weight.”
10a.m. to 12p.m., 12p.m.-2p.m., 3:p.m.
Mental Tasks: It may be best to get demanding mental tasks done between the hours of 10 a.m. and noon because this is when the brain is at its pinnacle of mental acuity, according to a 2008 paper published in the journal Mind, Brain and Education. The human mind tends to be sharpest in the morning, dwindle during the afternoon, and bounce back a little after 3p.m. Tasks that are not so mentally draining may be best to get done during the afternoon period and the tougher tasks can be picked back up around 3p.m.
2p.m. to 3p.m.
Power Naps: “The best time for a power nap is during the mid-day dip on alertness, usually around 2 p.m.,” said Prof. James Maas, psychology, a world expert on sleep. Between the hours of 1 p.m. and 3 p.m. factors in a person’s circadian rhythm cause the body to take a “post-lunch dip,” which is the cause for that drowsy feeling that many people get in mid-afternoon. A person’s body temperature also starts to dip at this time, just as it does at the time before a person goes to bed at night. To combat the fatigue, instead of grabbing a power drink or breaking for coffee, taking a quick power nap should be enough to recharge a person’s cognitive and physical performance.
“Naps should be either 15 to 20 minutes or 90 minutes to achieve a complete REM cycle,” Maas said.
5p.m. to 6p.m.
Drinking Alcohol: Although drinking alcohol will interfere with any kind of cognitive processing that one may be doing during the day, there are health benefits associated with drinking an occasional glass of red wine.
“The best time to drink alcohol like red wine is just before dinner,” said David Levitsky, nutrition. Research has shown that the liver metabolizes and detoxifies alcohol most efficiently and quickest between the hours of 5 and 6 pm. “Drinking at this time will also help relax you just before you begin the digestion of the meal.”
6p.m. to 7p.m.
Working Out: According to a person’s circadian rhythm, the best time to work out is during late afternoon. At Northwestern University, Prof. Phyllis Zee, associate director of the Center for Sleep & Circadian Biology, recommended working out between the hours of 2 and 4 p.m. because this is the time when a person’s body temperature is at its peak. The body’s temperature is about one to two degrees warmer than it is in the morning around this time she said. Increased body temperature is ideal for participating in strength, speed and power activities because it makes the muscles more flexible and less prone to injuries. Then again, researchers like Prof. Levitsky recommend that anytime is the best time to exercise. “The body is amazingly adaptive,” he said. “As soon as you begin to exercise, the demands for the exercise by your muscles will dominate over any other modulating influence such as time of day or whether you have just eaten.”
9p.m./11p.m. to 6a.m./8a.m.
Sleeping: For most people normal circadian rhythms are set make them to fall asleep around 9 or 10 and wake up around 6 or 7 a.m. For most college students though, “the teenage brain is maximally set to fall asleep at 3am and wake up at 11am, but alas, that's not when classes are scheduled,” said Maas. “Keeping a regular sleep and rising time will help you overcome the delayed circadian rhythm,” he says. To obtain optimal amounts of rest, he suggested that students “go to bed 8 to 9 hours before you have to get up for classes.”
Scheduling Medical Appointments: In an episode of his show, Dr. Oz explained that doctor’s appointments are best scheduled first thing in the morning to avoid the long waiting room times that come when the doctor falls behind schedule. Studies show one of the problems that cause doctor’s offices to get backed up is that many doctors schedule their appointments in 15-minute blocks while a lot of appointments end up taking 20 to 30 minutes.
Surgeries are best scheduled before noon. A study at Duke University analyzed over 90,000 operations and found that problems in surgery came most often during 3 p.m. and 4 p.m. and were at a low between 9 a.m. to 12 p.m.
The difference in adverse effect rates from surgery may be linked to the surgeons’ own circadian rhythm which dips late afternoon, but is at its peak during the late morning.
When scheduling a dentist appoint for a procedure like a root canal, it is best to have it done during the early afternoon. European studies have found that during the afternoon local anesthesia lasts three times longer because epinephrine levels in the body are higher than at any other point in the day. Epinephrine, which is also called adrenaline, is a hormone that can constrict the local anesthesia, making it last more effectively producing less pain.