McAlpine's favorite on-the-go exercise is a classic for a reason: Push-ups are one of the most effective bodyweight exercises around. "Primarily, this move will target your chest, triceps, and your anterior deltoid muscles (the front of your shoulders)," says McAlpine. It also seriously works your core. Plus, there's something that just feels badass about working on push-ups and seeing yourself improve over time. "I personally love that feeling of strength that comes from this simple move," says McAlpine.
Start the clock, and do as many squats as you can — while maintaining perfect form — for 30 seconds. Then rest for 10 seconds, and do as many single-leg deadlifts as you can (again, with perfect form) for 30 seconds. Stick to one leg with the deadlifts for the full 30 seconds. Then rest for 10 seconds again. Finish up with 30 seconds of glute bridges. Rest for a minute or two, and then start all over again.
Well, good (bad?) news: People who have dedicated their professional lives to defying Newton's First Law (you know them as "personal trainers") don't often have the luxury of skipping a sweat session. Next time you find yourself in need of a workout but without any of the things you think you need to get one, we got them to share the best workouts and circuits and exercises you can do anyway—no gear required.
Countless studies show that many types of exercise, from walking to cycling, make people feel better and can even relieve symptoms of depression. Exercise triggers the release of chemicals in the brain—serotonin, norepinephrine, endorphins, dopamine—that dull pain, lighten mood and relieve stress. “For years we focused almost exclusively on the physical benefits of exercise and really have ignored the psychological and emotional benefits of being regularly active,” says Cedric Bryant, chief science officer of the American Council on Exercise.