Instructions: Choose 3 to 4 exercises from the list below. Perform each for 30 to 60 seconds, then immediately continue to your next move. Once you've completed all three, rest for 15 to 30 seconds, ...

Sit-ups are a great foundational exercise to work your abs, though you don’t need to spend hours on endless repetitions to strengthen your midsection. Instead, use this equipment-free, no-repeat abs ...