Let’s rethink that.
“Your workout time is precious—and traditional abs exercises are an ineffective way of burning fat and building muscle given the limited number of muscles recruited and the low level of muscular overload,” says Brynn Putnam, founder of NYC’s high-intensity Refine Method.
Instead, Putnam recommends total-body movements that work mutiple muscle tissues directly. “You’ll soon find that every exercise is a core exercise if you're working with enough resistance so your core muscles must stabilize your spine to allow your arms and legs to produce force,” she says. Suddenly, your 20-minute “abs” workout becomes a worthy sub for a full workout when time is tight.
Complete the next 5 exercises, one minute every, back-to-back and repeat for four rounds, resting provided that you completely have to.