This may be the most worthwhile reason for exercising there is. Studies have shown how people who exercise are at a significantly reduced risk of developing dementia like Alzheimer’s disease. And even for people who start exercising relatively late in life, brain volume can actually increase over time, as can scores on memory tests, compared to people who don’t exercise (their brains shrunk over time, which is normal part of aging).
Most people find they can't do a full minute of press-ups without their muscles giving in to begin with. If your muscles fail on you, don't think of it as a point of no return. Instead, take a moment to rest and continue with the exercise for as long as possible, just as you did the abdominal plank. Bit by bit, you'll find your press-up stamina improving.

Stand with your feet placed shoulder width apart and arms extend straight to your sides, raised at shoulder height. Now, do 50 small circles with your hands by rotating them in the forward direction. Then switch to 50 small backward circles. The backward and forward arm movement tones all the muscles of the arms including the triceps, biceps, shoulders and back muscles as well.
So short of moving to a blue zone, exercising for just 10 minutes a day, or 75 minutes a week, can earn you an extra 1.8 years. The findings held true even for those individuals who were overweight or obese; adding exercise helped them live longer, while being obese and inactive decreased life span by up to 7.2 years. The benefits of adding more exercise increased and then plateaued at about 300 minutes of weekly exercise (or an hour five days a week) adding an extra 4.2 years of life.
The workout includes a dynamic warm-up to get your blood flowing and prep your body for the rest of the work ahead, and a cool-down to help you slow back down and wrap it all up. If you want to make the workout more challenging—maybe you've done it a handful of times and are ready to turn things up a notch—add weights to the lunge and squat movements. You can also, like Sims said, add another round of the main strength circuit.
HOW TO DO IT: Assume a wide sumo stance with your feet farther than shoulder-width apart and your toes pointed out slightly. Drop your weight into your heels and lower your hips until your palms reach the box without rounding your lower back. Jump your feet back into a plank. Reverse the movement and repeat for 30 to 60 seconds. Add height to the box if the movement is too difficult.
To perform reverse curls you will need a barbell with weight, enough to provide a challenging workout but not so much that you can’t complete a third set. Hold the bar at your waist in an overhand grip with your feet about shoulder-width apart; this is your starting position. Then you simply perform your basic curl exercise, flexing your muscles to lift the bar to shoulder level and return to starting position.

Stand whit your feet placed hip width apart and arms raised straight to the sides, raised at shoulder height and the fingers together. Begin by keeping your palms facing towards the floor and then slowly rotate your thumbs towards the back until the palms are facing the ceiling. Slowly rotate the thumb down and forward. Repeat it 30 times at a stretch for best results.
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.
×