After three weeks of nutrition education and adding more vegetables to your daily diet, we've got a brand new challenge for you.

All across the country, as the cooler fall temperatures descend on us, races are taking place - walks, runs, 5k races, marathons, and everything in between.

Now is as good a time as any to begin training for a road - or, to re-double your efforts if you've fallen off the wagon just a bit. So our challenge for you beginning this week is to pick an event (5k, 10k, whatever!) and begin a training program with the end goal of finishing that event.

Different readers will, of course, run or walk different length events and with different intensities. But wherever you start, and whatever you pick, there are some things that hold true about training programs across the board.

How do you pick the right race (run or walk) for your fitness level? Well, first check out Running in the USA for a comprehensive list of upcoming events all across the nation, and at all levels and distances.

One of the most critical aspects of this challenge will be to pick the right distance and level run/walk for you and your goals. If you're a beginner, and looking to do your first run, start slowly - register for a 5k (3.1 miles) in the coming months. Mastered the 5k? Maybe it's time to look at a 10k (6.2 miles) or even a half-marathon (13.1 miles).

The key to picking the right race, just like any other aspect of goal-setting, is to challenge yourself without setting up for (a) failure, and (b) unrealistic expectations and disappointment. For someone who has never before run a race, signing up for a marathon ten weeks from now is probably a bad idea. But a 5k ten weeks from now for a beginner is much more realistic and worthwhile.

Once you've picked a race and determined what's a realistic event and distance for your goals, training for it becomes the most important focus. We'll discuss specific training tips over the next few weeks, but there are a few steps to keep in mind from the outset.

The most important part of creating a training program is determining your end goal. If you are a beginner, and your end goal is simply to finish a 5k, your training program might be less intense (and appropriately so) than an intermediate runner who is looking to set a personal best at a 10k event.

Some goals to consider might include finishing an event in a certain time, or finishing an event without walking the entire time. Once you decide an appropriate goal, write it down! We'll cover goal-setting in a future challenge, but in the meantime it's important to commit to a goal - and writing it down and holding yourself to it is the first step. Turn the goal into a statement - and affirm it a few times every day. For example, "I will run my first 5k in under 30 minutes."

But more than just telling yourself what you want, it's important to go out and get it! There are countless ways to create a training program, but the simplest and best is to slowly and consistently build distance on your runs or walks, to build stamina and prevent injury.

Follow the 10% rule when training - never increase your total running distance more than 10% in a week. In other words, if you run 10 total miles across the first seven days of your training program, over the next seven, run 11 total miles - a 10% percent increase in running distance.

Any larger jumps in distance increase in a week's time can lead to overtraining and other injury issues that are otherwise easily preventable. Another important aspect of the 10% rule is that it allows for realistic and sustainable jumps in distance, without setting the bar too high, failing, and discouraging yourself from training any longer.

Different runners and walkers, at different levels, will have different schedules for their training. If you're a beginner, and looking to run your very first race, start out running three or four days a week. As you get in better shape and build strength, slowly increase the frequency of days you run each week - but no matter what you're training for, always allow yourself at least one day each week to do a non-running activity (swimming, weight lifting, etc.) in order to take some stress and strain off your joints and legs.

It can take a while to establish a routine, especially as a beginner. But it's critical to give yourself a plan and a goal to work with - specific items that call for action will make you more motivated!

So this week, get out there, pick a race, and begin a training program. Do it safely and slowly, while still challenging yourself. Good luck and happy running or walking!

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