Exercise improves physical health. Physically active individuals have a much better health outlook than their sedentary peers. Even modest regular physical activity has a positive influence on people's health and vitality. A minimum of 20 to 30 minutes of moderate activity a day most days of the week will benefit health and assist with weight loss. A formal workout is not necessary to have these benefits; a brisk walk will suffice (although a more vigorous workout will suffice that much more).
HOW TO DO IT: Start with your left leg forward and your right leg back. Place your left foot onto one end of a towel and grab the other end in your right hand. Pull the towel as hard as you can without holding your breath. Hold for 30 to 60 seconds, then switch sides and repeat. If you can’t maintain the hold continuously, break it up into shorter five- to 10-second bursts with brief one- or two-second rests in between.
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.
Maybe you exercise to tone your thighs, build your biceps, or flatten your belly. Or maybe you work out to ward off the big killers like heart disease, diabetes, and cancer. But how about sweating to improve your mind? "Exercise is the single best thing you can do for your brain in terms of mood, memory, and learning," says Harvard Medical School psychiatrist John Ratey, author of the book, Spark: The Revolutionary New Science of Exercise and the Brain. "Even 10 minutes of activity changes your brain." If you need a little extra incentive to lace up those sneakers, here are five ways that exercise can boost your brainpower.
And exercise stimulates the endocrine system and can improve reproductive function, explains Berger. The endocrine system is made up of glands that secrete hormones in the body; this system plays a key role in regulating metabolism, mood, tissue function, and sexual function. Bottom line: There are a lot of ways your sex life can get a boost from working out.

HOW TO DO IT: Start in a bent-knee push-up position with your palms underneath your shoulders and knees bent at 90-degrees. Kick your right leg in front of you and assume a one-arm, one-leg hip bridge. Hold for one count, then reverse the movement and repeat on the other side. Move at a slower, more-controlled pace if it’s difficult, or even try a modified version called “sit-throughs,” where you sit on the outside of your hip as you move to each side.
Another study this month, from Mayo Clinic, found that exercise in older people who were formerly sedentary had at least as strong an impact as in it did in young people—at least in the kinds of genes that were expressed. The study also found that these changes were much more robust in response to interval training than to weight lifting or moderate exercise. Which may mean that for some things, the type of exercise we chose matters.

But the idea that banging out a workout when you don't have access to your usual equipment or space is one that trainers are quick to debunk. Sure, they know their way around a gym floor and a smart workout program, but they also know that when you're traveling, ultra busy, or just don't feel like dealing with the gym, a routine of challenging bodyweight exercises will get the job done.

And perhaps one of the best new findings about exercise — especially if you, like many people, struggle to find the time to fit it into a busy day — is that all those benefits of physical activity can be had even if you only squeeze in a few minutes of exercise a day. While doctors used to think that we needed to engage in 30 to 60 minutes of exercise a day, new research is finding that we can see benefits with shorter bursts of physical activity. “As little as 15 minutes a day of high-intensity activity that leaves you breathless, like swimming, can kick start your metabolic rate and reduce body fat and increase muscle mass,” says Dr. Berger.