Copyright New York Post
A new study reveals that the foundation of solid sleep may rest on four core habits. Over 31 days, roughly 39,000 healthy adults participated in what a team of international researchers dubbed the “Core Four Challenge.” The objective of the study was to determine the combined impact of four circadian-aligning behaviors on sleep quality and overall health. Participants were monitored with a WHOOP wrist device that tracked their sleep and cardiorespiratory metrics. Members of the research team, who work in the Department of Performance Science for WHOOP, collected data over three months to establish a baseline and measure results during and after the four interventions. They found that these changes improved sleep consistency, resting heart rate and heart rate variability (HRV). “Integrating four simple behaviors into daily life may offer a practical, evidence-based approach to improving sleep regularity and overall health,” the study authors wrote in the journal Sleep. “This study reinforces the growing body of research supporting circadian alignment as a cornerstone of human performance and wellness.” Light exposure Morning sunlight exposure has long been considered key to optimizing circadian rhythm. Our bodies wake up because our internal clock, or circadian rhythm, responds to light exposure in the morning. Morning light helps the body release the hormone cortisol, which signals that it’s time to wake up. In darkness, the brain produces melatonin, which tells the body to sleep. In addition to morning sunlight, experts also noted that it’s important to shut off blue light-emitting screens 30 to 60 minutes before bedtime. Time-restricted eating Sleep and eating are intimately linked due to their shared involvement in metabolic signaling and circadian rhythm. Experts agree it’s best to finish dinner at least two to four hours before falling asleep to allow the body to fully metabolize food and store excess energy that could disrupt sleep. These evening meals should include foods with a low glycemic impact and slow-digesting properties — like lean proteins, healthy nuts or non-starchy vegetables — to avoid blood sugar spikes. It’s also best to avoid the traditional “midnight munchie” snacks like junk food, cookies, ice cream and pizza — especially alcohol, as it has been shown to have particularly adverse effects on sleep quality. Breathwork Deep breathing exercises can physiologically calm the body by lowering heart rate, releasing muscle tension and changing skin conductance, all of which help send us to slumberland. The efficacy of breathwork relies on the connection between breath and the parasympathetic nervous system, which regulates rest and digestion. Activating the parasympathetic nervous system sends the body into a more relaxed state by reducing blood pressure and slowing heart rate. This increase in parasympathetic activity also quells the sympathetic nervous system, which is responsible for our fight-or-flight response, thereby setting the stage — or bed — for restorative rest. Zone 2 cardiovascular training Training zones are used in fitness to categorize the intensity of a workout. Zone 2 is exercising at about 60% to 70% of someone’s maximum heart rate. In Zone 2, you should be able to hold a “light” conversation, though you may be breathing slightly harder than normal. This is sometimes referred to as the “talk test.” In the end, researchers are hopeful their findings will encourage people to adopt and implement these four strategies to improve their sleep and overall health. “The findings demonstrate that engaging in consistent, simple routines that support circadian health — such as exposure to morning light and mindful timing of meals — can yield measurable improvements in both recovery and cardiovascular performance,” the study authors concluded. The National Sleep Foundation suggests adults get seven to nine hours of sleep every night, with 57% of Americans recently admitting they’re not hitting the mark. Inadequate sleep can raise the risk of chronic health problems like heart disease, high blood pressure, diabetes and obesity.
