The idea of a marathon runner often conjures images of young, long-legged, sinewy athletes in peak physical form that can be achieved and maintained only with an ultra-strict diet, exercise program and sleep regimen.

Not so, according to marathon coach Jenny Hadfield, who co-authored “Mara-thoning for Mortals,” a book geared to get average people of all ages, shapes and sizes, motivated to train for and complete marathons.

“Training for a marathon is a great way to stay in shape and whether you end up running it in two hours or walking it in eight, there’s a great sense of accomplishment in completing a race,” Hadfield stated in a news release. “That’s why I find more and more middle-aged and older Americans are getting involved in this sport.”

A typical training program includes a tailored schedule — three to four days per week of running or walking — that is geared toward a specific goal race that works to motivate the marathoner to exercise regularly. For Hadfield, running or walking the race is the celebration.

Hadfield offers the following tips in “Mar-athoning for Mortals” to get would-be mar-athoners started:

• Select a goal race. If you’ve never run or walked a marathon, it’s wise to aim for a half marathon.

Pick a race that allows you to properly train, typically six to eight months.

• Purchase a pair of running shoes that fit well to support your upcoming training.

• Follow a safely designed training program such as the programs outlined in Hadfield’s book.

• Find a group with which to train. Most running stores sponsor runs and walks out of the store. Some may even have mar-athon training groups.

• Listen to your body for signs that you are doing too much too soon.

• Treat sore muscles by using heat wraps that provide hours of consistent, low-level heat to relieve pain and speed recovery and healing.

If the mere thought of participating in a marathon is daunting, Hadfield recommends taking the training process on one day at a time and setting achievable short-term goals along the way to maintain your spirits.

As many of her older “students” have found, training for a marathon can be as rewarding as crossing the finish line when you take into account the overall cardiovascular and respiratory benefits of exercising regularly.

So put on your running shoes and consult your doctor prior to beginning any strenuous exercise program.