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.
You'll also build muscle to fill out your arms and firm them up. “Generally, when people are complaining about underarm jiggle, they’re usually referring to the area that is governed by the tricep,” says Williams. “If the jiggle or looseness in that part of your arm is due to a lack of muscle, then strengthening and building muscle in your tricep will also create some change in the aesthetic of that area.” She recommends performing triceps push-ups, extensions, and dips to hone in on that area and add some muscular definition to your arms.
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.
Back to the tricep pushups and really activating those tricep muscles for toned arms.  If you need a rest, that's totally cool. Just take a break in the up position and maintain that plank form. This way you are still working your arm muscles just by holding your body weight up. So that's totally fine for some of our beginners out there. For those who are more advanced, we want you going as hard as you can and trying to hit that 15 to 20 reps. You're doing great.
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