How to Get Fit Quickly in Less Than 3 Hours a Week

For most people who work, have a family and a full social schedule, squeezing in workouts can be a constant struggle. The good news: You don't need to invest a ton of time to get fit quickly. If you can carve out 45 minutes three times a week, you can get fit enough to lose weight, increase strength, become a better runner, and get ready to run a 5K.

This goal-based get-quick-fast guide is ideal for busy professionals and parents who want to reap the benefits of running without the commitment to a traditional run training program. Before you begin, figure out why you want to get fit: Do you want to get stronger and lose weight, or do you want to learn to run faster? This guide is divided into two goal-specific plans.

More: Do Your Running Goals Match Your Reason for Running?

Goal #1: To Increase Strength and Running Fitness

"If you have three days a week to work out, you don't need to do the same thing every day," says Jay Johnson, an adult and high school running coach who has a master's degree in kinesiology and applied physiology. "The body will make a great adaptation in the first three weeks if you did the same thing every day, but it's going to taper off."

Johnson recommends that individuals with 45 minutes three times a week to devote to exercise dedicate one day to just running, one day to strength work and the third day to a combination of running and strength.

More: Strength Train to Improve Running Economy

This cardio-strength combo is particularly ideal for those who want to drop pounds and increase muscle mass, as it incorporates both catabolic and anabolic stimuli. Catabolism is the breaking down of something, and anabolism is the building up of something. Exercise like running burns calories and has a catabolic effect on the body; strength training also burns calories, but it has more of an anabolic effect on the body because it builds muscle. People who want to get fit quickly want both anabolic—because muscle requires more calories for maintenance than fat—and catabolic types of exercise. Those who want to lose weight need both stimuli with a net catabolic effect that can be achieved through exercise and a diet with the appropriate number of calories.

In addition, there's a hormonal response to strength work that produces a protective effect, according to Johnson. Strength work improves bone density and releases human growth hormone.

"There's an up regulation of testosterone and human growth hormone when doing strength exercises, and this helps keep you injury free," says Johnson. "That's why baseball players like Sammy Sosa were taking human growth hormone more than steroids. Think about the joint problems and all of the other injuries an older baseball player can have. The human growth hormone helped protect them from all of those things."

More: 4 Essential Strength Moves for Runners