Fit In Exercise With Harley Pasternak's 5-Minute Workouts

The "5 Pounds" author says you only need one exercise each day.

— -- Time seems to be the number one reason so many of us say we don’t make it to the gym but it doesn't have to be the case.

As part of the “GMA” Yahoo Your Day series, “GMA” met up with Michele Promaulayko, Yahoo Health’s editor in chief, and celebrity trainer Harley Pasternak to bust fitness myths and demonstrate a quick, efficient workout routine.

Promaulayko says one fitness fallacy is that working out in a hot room equates to a greater calorie burn. “That’s not true,” she said. “Your body burns more in a cold environment.”

A second myth is that by eating less food you will lose more weight. “Of course, there's an ideal number of calories you want to consume in a day,” Promaulayko said. “But you also don't want to consume too few calories, because then your metabolism slows down to conserve energy. So you eat a little more, you burn more.”

A third myth is that doing crunches will lessen your belly fat. “You can't spot reduce,” Promaulayko said. “So what you want to do is burn fat all over your body and have a nice, clean diet and then those abs will be revealed.”

Pasternak, the author of “5 Pounds: The Breakthrough 5-Day Plan to Jump-Start Rapid Weight Loss (and Never Gain It Back!),” showed ABC News’ Sara Haines a no-excuse workout that focuses on just one movement each day of the week.

“Each day of the week, we pick a different exercise that does a different part of the body so at the end of the seven days, you've hit all the major body parts,” Pasternak said. “You don't even need to change. You don't need to go to the gym.”

Pasternak says each of the below seven moves should only take five minutes out of your day each day.

MONDAY: Reverse Lunges

Start off with your feet shoulder-width apart. Step back with your right leg, drop your knee down and return. Rotate with the other leg.

TUESDAY: Superwoman

Lie face down on the ground with both your legs and your arms fully extended and off the ground. Raise your arms and legs up and down, never touching the ground. “Every time you come up, you’re working not only the erector spinae, but if you come to the very top, your glutes are contracting,” Pasternak said. “The higher the thighs go, the more the glutes are working.”

WEDNESDAY: Lying Dumbbell Tricep Extension

Lie on a bench or elevated flat surface with a dumbbell or weighted item in each hand, arms extended above your head. Bring the dumbbells down on either side of your head and then back up, repeat. “Imagine that your fists are hammers and there’s a nail in the ceiling,” Pasternak said. “And nail them up all the way.”

THURSDAY: Stiff-Legged Dead Lift

Hold a dumbbell or weighted item in each hand with your feet shoulder-width apart. Slide the dumbbells up and down your leg, pushing your butt back. Then bring your hips back to neutral. “This is all about feeling the hamstring stretch,” Pasternak said.

FRIDAY: Standing Dumbbell Curl Press

Hold a dumbbell or weighted item in each hand with your feet shoulder-width apart. Curl the dumbbells up, press them above your head, bring them back down and extend. “This is a good time saver,” Pasternak said. “It's biceps, brachioradialis and shoulders all in one.”

SATURDAY: Single Arm Dumbbell Row

Stand in a lunge position with the dumbbell in your right arm and left forearm on your bent left thigh. Looking straight ahead, pull your right elbow up along your body. Repeat on the other side. “Imagine there's a rope attached to your elbow. And we're just dragging the elbow up along your body,” Pasternak said.

SUNDAY: Standing Dumbbell Side Bend

Stand with your feet shoulder-width apart with a dumbbell or weighted item in your hand. Bend to the side opposite the dumbbell to work your obliques. Repeat on the other side.