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Is there an optimal time of day to exercise?
Two new studies say yes. Unfortunately, each claims a different time.
- Research at the Weizmann Institute of Sciences declares evening to be the best time for an exercise session.
- Not so fast, says a new study at UC Irvine, which replies that late morning is the optimal workout time.
- Both studies involved mice on treadmills and measured different markers to produce their results.
We know timing is everything, but does everything rely on timing? When it comes to when you exercise, the answer might be yes.
Two complementary studies were recently published in the journal Cell Metabolism, detailing the relevance of circadian rhythm on exercise. Both studies relied on mice huffing it on treadmills (along with a dozen human counterparts in one of the studies). Both presented an optimal time of day to exercise. The problem is, each study claims a different time.
In the first, mice were put on varying cardio protocols at different times of day. "Mouse evening" is different than "human evening" since rodents are nocturnal. According to this research, evening appears to be the best time of day for exercise efficiency.
The team, led by Dr. Gad Asher in the Department of Biomolecular Sciences at the Weizmann Institute of Sciences, focused on skeletal muscle. They discovered higher levels of post-workout ZMP during mouse evening, affording the rodents an increased exercise ability. When 12 humans were tested in a similar manner the result was the same. As the team writes,
"The distinct daytime and exercise-type transcriptomic and metabolic signature in skeletal muscle point toward a difference in nutrient utilization and metabolic pathway activation, in particular, fatty acid oxidation and glycolysis."
Asher believes this offers a leg-up on those that hit the treadmill in the evening, noting that ZMP is "an endogenous analog of AICAR [aminoimidazole carboxamide riboside], a compound that some athletes use for doping." Apparently, our internal alarm clock offers access to our inner pharmacy at different times.
Morning vs Evening | Best Time of Day to Workout
Not so fast, says Dr. Paolo Sassone-Corsi at the Center for Egpigenetics and Metabolism at UC Irvine. His team also investigated the effects of circadian regulation on metabolism. He says that by the end of the study his team looked out a much different time window.
"Using mice, we compared the impact of exercise on the skeletal muscle metabolism at different times of day. We discovered that exercising at the correct time of day — around mid-morning — results in more oxygen in the cells and a more rejuvenating effect on the body."
Sassone-Corsi measured changes in muscle tissue as they related to glycolysis and lipid oxidation. The key component was a transcription factor, HIF-1α, and its role in exercise efficiency. Homing in on this particular process offered another perspective.
Specifically, Sassone-Corsi says that our bodies utilize carbohydrates and ketone bodies better during a late morning workout; we also break down fats and amino acids more efficiently during this phase.
While both studies involve circadian rhythms, Sassone-Corsi admits that mice living in a laboratory experience reality differently than humans. Physiological differences between an early rising human and a night owl signify varying optimal times of day for pretty much everything, workouts included. If you're not accustomed to hitting the gym at the break of dawn, it is unlikely that a 6 a.m. session will be better when compared to your normal evening regimen.
Nathaniel Clyne attends the gym session during the AFC Bournemouth warm weather training session at NAS Sports Complex on March 21, 2019 in Dubai, United Arab Emirates. Photo credit: AFC Bournemouth / AFC Bournemouth via Getty Images
In my experiences, there are advantages to both. In the morning (my personal preference, being an early riser), exercise wakes you up and prepares you for the day ahead. I notice a qualitative difference between getting on my laptop on days when I work out first compared to when I do not.
Other benefits of a morning routing include:
- More efficient weight loss
- REM sleep aids in motor control
- Early birds are more consistent (likely because willpower is a limited resource)
Yet evening exercise also has advantages. For example, your body is more limber, having moved around all day; hitting the yoga mat first thing in the morning can be torturous. The wash of chemicals after an evening session sets you up for a restful sleep. Other research suggests that evening workouts allow you to blow off steam from your day while also increasing the intensity of your session. Strength and flexibility are highest in evening.
The answer to the optimal workout time appears to be: it depends. Like diet, exercise programs are individual. Experience and habitual patterns must be factored in. The most important takeaway from these studies is the fact that exercising at any time of the day is better than not exercising at all. Whatever your movement protocol, that you have one is the most important factor.
A Mercury-bound spacecraft's noisy flyby of our home planet.
- There is no sound in space, but if there was, this is what it might sound like passing by Earth.
- A spacecraft bound for Mercury recorded data while swinging around our planet, and that data was converted into sound.
- Yes, in space no one can hear you scream, but this is still some chill stuff.
First off, let's be clear what we mean by "hear" here. (Here, here!)
Sound, as we know it, requires air. What our ears capture is actually oscillating waves of fluctuating air pressure. Cilia, fibers in our ears, respond to these fluctuations by firing off corresponding clusters of tones at different pitches to our brains. This is what we perceive as sound.
All of which is to say, sound requires air, and space is notoriously void of that. So, in terms of human-perceivable sound, it's silent out there. Nonetheless, there can be cyclical events in space — such as oscillating values in streams of captured data — that can be mapped to pitches, and thus made audible.
Image source: European Space Agency
The European Space Agency's BepiColombo spacecraft took off from Kourou, French Guyana on October 20, 2019, on its way to Mercury. To reduce its speed for the proper trajectory to Mercury, BepiColombo executed a "gravity-assist flyby," slinging itself around the Earth before leaving home. Over the course of its 34-minute flyby, its two data recorders captured five data sets that Italy's National Institute for Astrophysics (INAF) enhanced and converted into sound waves.
Into and out of Earth's shadow
In April, BepiColombo began its closest approach to Earth, ranging from 256,393 kilometers (159,315 miles) to 129,488 kilometers (80,460 miles) away. The audio above starts as BepiColombo begins to sneak into the Earth's shadow facing away from the sun.
The data was captured by BepiColombo's Italian Spring Accelerometer (ISA) instrument. Says Carmelo Magnafico of the ISA team, "When the spacecraft enters the shadow and the force of the Sun disappears, we can hear a slight vibration. The solar panels, previously flexed by the Sun, then find a new balance. Upon exiting the shadow, we can hear the effect again."
In addition to making for some cool sounds, the phenomenon allowed the ISA team to confirm just how sensitive their instrument is. "This is an extraordinary situation," says Carmelo. "Since we started the cruise, we have only been in direct sunshine, so we did not have the possibility to check effectively whether our instrument is measuring the variations of the force of the sunlight."
When the craft arrives at Mercury, the ISA will be tasked with studying the planets gravity.
The second clip is derived from data captured by BepiColombo's MPO-MAG magnetometer, AKA MERMAG, as the craft traveled through Earth's magnetosphere, the area surrounding the planet that's determined by the its magnetic field.
BepiColombo eventually entered the hellish mangentosheath, the region battered by cosmic plasma from the sun before the craft passed into the relatively peaceful magentopause that marks the transition between the magnetosphere and Earth's own magnetic field.
MERMAG will map Mercury's magnetosphere, as well as the magnetic state of the planet's interior. As a secondary objective, it will assess the interaction of the solar wind, Mercury's magnetic field, and the planet, analyzing the dynamics of the magnetosphere and its interaction with Mercury.
Recording session over, BepiColombo is now slipping through space silently with its arrival at Mercury planned for 2025.
Research suggests that aging affects a brain circuit critical for learning and decision-making.
As people age, they often lose their motivation to learn new things or engage in everyday activities. In a study of mice, MIT neuroscientists have now identified a brain circuit that is critical for maintaining this kind of motivation.
Researchers find a key clue to the evolution of bony fish and tetrapods.
- A new study says solar and lunar tide impacts led to the evolution of bony fish and tetrapods.
- The scientists show that tides created tidal pools, stranding fish and forcing them to get out of the water.
- The researchers ran computer simulations to get their results.
Neil deGrasse Tyson Explains the Tides<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9913a65f847775722d7c23d40d78938b"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/dBwNadry-TU?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
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