Fast Run, Slow Run, Five Day, Two Day: It All Depends on Your Goals

The New York Road Runners Club has just waded through 200,000 applicants to choose the lucky tens of thousands of entrants for next November’s NYC Marathon. And you can bet each and every one of them is planning to run as fast as they possibly can.

Should you?

In the end, the answer to what kind of running or exercise works best for any one person depends on their goals.

If you’re thinking of training for a marathon, Runner’s World has a race time predictor where you can plug in a time that you have done on a 5k (3.1 mile) or 10K (6.2 mile) run and figure out your expected marathon time. Obviously, it takes into account that the longer distance means slower mile splits on a 26.2-mile marathon.

“When running a new distance, it should be considered a ‘long’ run, regardless of the actual mileage,” wrote Susan Paul in a reader-advice column in Runner’s World back in 2013. The advice seems just as sound today. “If you have never run 10 miles before, then your first 10-mile run should be considered a long run; whereas, a veteran marathoner would not consider a 10-mile run to be a long run. For experienced marathoners, long runs are typically those runs of 18 miles and above. Just think, you may get to that point some day too!”

As the Cleveland Clinic explains, all exercise is designed to increase endurance, that is, how well your heart and lungs work to supply the body with oxygen and how long your muscles can repeatedly contract against resistance.

Fast runs push your heart and lungs to work harder, which according to Hospital for Special Surgery sports med doctor Todd McGrath, in an interview in Today.com, boosts cardiovascular health and muscle mass. And, while any exercise burns calories, John Vasudevan, associate professor of physical medicine and rehabilitation at Penn Medicine, added that, “Running faster burns more calories in a shorter period. You get to the fat-burning stage a lot faster.”

On the other hand, running longer and slower is less likely to trigger pain or, worse yet, injuries such as hamstring strains, sprained ankles, or tendinitis. “Jumping right into running fast can be particularly hard on the muscles, especially for a novice runner,” warns McGrath.

That being said, it’s important to note that there are physical and practical downsides to both fast and slow runs. The fast runs increase the risk of acute musculoskeletal injures like hamstring strains, sprained ankles, or tendinitis.

Long-term endurance running has its advantages even if not getting to the fat-burning stage as quickly.

“The best way to build endurance is to create a situation that needs endurance, which is longer distance and longer time,” said Dr. Vasudevan, to TODAY.com.

But slower runs are not completely problem-free either. While slower runs sound easier on the body, in fact the longer time spent moving could also mean repeated stress on all those leg muscles, ligaments, tendons, and joints, which may turn out to be linked to a laundry list of overuse injuries that include strains, knee issues, plantar fasciitis, stress fractures, and shin splints (pain in the front part of lower legs common among serious athletes).

Whether shorter, faster or longer, slower runs, there’s the unavoidable fact that any exercise pattern requires a person’s committing to carve out repeated periods of time from their regular schedule.

And for time-pressed New Yorkers, there was some good news for the so-called weekend warriors late last year.

Condensing exercise into one or two days a week may be enough to reap the many benefits of physical activity.

A study, published last October in Circulation, shows a weekend warrior routine can be just as effective at warding off a long list of serious illnesses as more pronounced regular exercise throughout the week. “When weekend warrior and regular activity were compared directly, there were no conditions for which effects differed significantly,” the study concluded.

If you have not done any exercise in awhile, it is always a good idea to have your annual physical checkup by a doctor first. And whether you’re a daily exerciser or a weekend warrior, experts say it is important to stretch before and after a workout.