They say strength comes from within, but when it comes to lugging groceries, opening sticky windows, and pulling down heavy boxes from the tippy-top shelf, it sure helps if your muscles have gotten a little action from some well-chosen exercises.The best ones get at your more neglected muscles while also forcing your body to work in synergy, meaning you’ll get stronger in a way that’s useful to your daily life. And the four moves ahead, each endorsed by a top trainer, do just that. In fact, several showed up on more than one list, with multiple experts assuring us they rely on these exercises themselves.For a full workout, slip on some of our favorite pieces of Old Navy activewear — made with summer-ready Go-Dry technology — and complete the moves as a circuit, moving from one to the next with little rest in between. Following a full round, take a one-minute breather; then repeat from the top, aiming for three to four sets.Need even more incentive? This routine requires no pricey gear, class, or gym membership — just a few props you likely already have laying around and your incredibly capable self.