This 20-minute home workout routine uses reps to exercise your full body, from your biceps to your core — and it can be done in a small space!Lifestyle expert Tommy DiDario, who covers men's fashion, grooming, travel, health, wellness and fitness for us, takes you through each workout group in the video above.He substitutes household items — like hardcover books (like Rach's latest cookbook, Rachael Ray 50!) — in place of yoga blocks and laundry detergent instead of free weights."[Try to] do every group of exercises 4 times — that's going to give you the best workout possible," Tommy says. "Do as many as you can. I like 10-15, but if it's a bit less, all that matters is you do it."Pro Tip: Give yourself about 30 seconds to a minute to rest in between. Be sure to start out slowly if you haven’t been exercising regularly or are a beginner.