The workout below, created by Jess Sims, NASM-certified personal trainer and instructor at Classpass Live, Shadowbox, and Fhitting Room in New York City, challenges your entire body and doesn't require a single piece of equipment. "It’s a full-body, dynamic workout that includes strength, power, mobility, and cardio," Sims says. "It’s also great because it’s customizable—if you have less than 20 minutes, you can do the circuit one time, or if you have more than 20 minutes you can do it three times."
Plyometrics are high-intensity bodyweight exercises that improve power, speed and physical performance. Think of burpees, jumping jacks, plank jacks and box jumps. These movements engage the whole body and raise your heart rate, sending your metabolism into overdrive. During a typical workout, your muscles are stretched and then contracted quickly to produce explosive force.
Jumping on the treadmill or cross trainer for 30 minutes can blow off tension by increasing levels of "soothing" brain chemicals like serotonin, dopamine, and norepinephrine. What's fascinating, though, is that exercise may actually work on a cellular level to reverse stress's toll on our aging process, according to a 2010 study from the University of California—San Francisco. The researchers found that stressed-out women who exercised vigorously for an average of 45 minutes over a three-day period had cells that showed fewer signs of aging compared to women who were stressed and inactive. Working out also helps keep us from ruminating "by altering blood flow to those areas in the brain involved in triggering us to relive these stressful thoughts again and again," says study coauthor Elissa Epel, an associate professor of psychiatry at UCSF.

Exercise can have a number of emotional benefits. Stress can be caused by elevated levels of the hormones cortisol, adrenaline, and norepinephrine. Exercise lowers these hormones, and increases serotonin, otherwise known as the happy hormone, which helps reduce stress. Working out can help keep depression and anxiety at bay. Plus, coping with mood disorders that are often associated with stress can be a little bit easier when you are in good physical shape.
Exercise has long been correlated with a longer life, but it’s only recently started to become clear why this might be. Studies, like a new one in the journal Preventive Medicine which found that exercise is linked to longer caps at the ends of chromosomes, have helped flesh this out a bit more. These caps, called telomeres, naturally shorten as we age, with each cell division. People who live a long time have telomeres that are in better shape than those who don’t—but there’s a lot we can do to affect the rate at which they shorten over the years. The team behind the new study looked at data from CDC's National Health and Nutrition Examination Survey, and found that for people who exercised regularly, their telomeres were 140 base pairs longer on average than sedentary people's. Which correlates to being years “younger” than their sedentary peers.
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