After three weeks of a cardiovascular challenge, I hope you not only picked a road race to train for, but you have started the training process. Keep it up! The race will be here before you know it. 

Our new challenge, which starts today, builds upon some of that training. Whether a runner, walker, or anything else, building muscle and protecting your joints from injury is an important part of being healthy and fit. 

So, our challenge over the next three weeks involves strength training. I'm challenging you to add a strength-training component to your exercise - at least three times a week, commit to building muscle! 

Over each of the next three weeks, I'll show you three strength training exercises to add to your training program. Today, a few upper body exercises - but first, some of the benefits of strength training. 

Weight lifting obviously makes you stronger, first and foremost. This is important for anyone active, because that added strength cushions and protects joints, and promotes better posture and body mechanics through the added strength. 

Strength training also plays a role in decreasing some common medical issues and diseases. Building muscle can effectively decrease arthritis pain in older adults, and significantly increase bone density and reduce the risk of bone fractures. It is also coupled with a cardiovascular exercise program to help those with type 2 diabetes improve glucose control and live a healthier lifestyle. 

Maybe the most important aspect of strength training for many are the weight loss benefits derived from it - you not only burn calories during strength training, but also afterwards, since more calories are used to make and promote muscle mass than those used simply after cardiovascular exercise. Pretty simply, more strength training means more calories burned! 

Now concerning specific exercises, there are a lot of things to consider. In the video above, I provided three upper body exercises to get you started on our weight lifting challenge. All three of the exercises can be done in a gym or a fitness center, but it's important to remember that not all weight lifting needs to take place on expensive machines, or with a gym membership. 

Push-ups, lunges, pull-ups, jump squats, and many more exercises (which we'll focus on over the next few weeks!) all promote muscle growth and weight loss just like any strength exercise on a machine in the gym. 

It can take a while to establish your strength training routine, especially as a beginner or someone unfamiliar with exercises. But take the three upper body exercises from this week as a base, and follow up over the next two weeks as I show you lower body and core exercises to complement these three exercises. 

So this week, get out there (or in the gym) and take at least 15 minutes, three times this week, to focus on simple strength training exercises to build in after your cardiovascular exercise. No need to go overboard, but build some muscle and burn some extra calories in the process!

About the author:Bobby DeMuro is the Founder of No Fizz America, a non-profit dedicated to health and fitness. He is also the founder FusionSouth, a sports conditioning firm. You can follow him on Twitter and Facebook .

You can listen to Bobby on his weekly radio show on Radio Exiles.