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[–><!–>High-intensity interval training is one of the best ways to pack a lot of exercise into a short period of time. HIIT workouts are so efficient because they alternate short bursts of very intense exercise with even shorter rests. That constant game of catch-up leads to quick cardio gains. –><!–>
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–>Bookmark this page to return to your workout. We’ll save your routine for you.<!–>
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Sources
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[–><!–>Jenny Liebl, master trainer at the International Sports Sciences Association
Milo F. Bryant, trainer based in San Diego
Mathais Sorensen, exercise physiologist at the UCSF Human Performance Center
Dr. Tamanna K. Singh, director of the Sports Cardiology Center at the Cleveland Clinic
Amanda Katz, on-set trainer–><!–>
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