Think state-of-the-art shoes, performance diets and well-thought-out racing strategies are only for elite runners?

Think again.

In reality, the slower you are, the more such measures improve your finish times, suggests new University of Colorado Boulder research.

The study, published in the journal¬†Frontiers in Physiology, takes a mathematical approach to answer a question that has perplexed exercise physiologists for years: How much does improving your body’s “running economy” – or the number of calories burned per second at an aerobic pace – really improve your speed?

The question has piqued the interest of the broader running community since July, 2017 when Nike introduced its Zoom Vaporfly 4% – a shoe that, according to previous CU research, improves running economy by 4 percent on average.

Members of the media, recreational athletes and some researchers have since assumed that meant runners wearing the shoes could cross the finish line 4 percent faster. With such savings, many predicted, a sub-2-hour marathon was well within reach.

But, according to the new study, the math is more complicated than that.

For the paper, the researchers re-examined treadmill studies of runners dating back decades, re-crunching the numbers to account for things like air resistance and oxygen uptake velocity (which both increase the faster you run).

They concluded that for runners moving slower than 9 minutes per mile, any percent improvement in running economy (due to better footwear, nutritional supplements, a tailwind, drafting or other measures) translates to an even higher percentage improvement in pace.

For instance, a 1 percent improvement in running economy for a 4:30:00 marathoner would make him or her 1.17 percent faster, dropping a significant 3 minutes and 7 seconds off their finish time.

On the flip side, for those who run faster than 9 minutes per mile, each percent improvement in the body’s gas mileage results in less than that percentage improvement in pace. For instance, that same 1 percent improvement in a 2:03:00 marathoner would enable him to run only .65 percent faster, a mere 47 second improvement.

All this is good news for recreational runners, say the authors.

A lot of times recreational runners assume these things are just going to benefit elite athletes when the reality is they can benefit even more than the elites.

A slower runner, slipping on a pair of shoes which improve running economy by 4 percent could actually translate to as much as a 5 percent improvement in finish times. Meanwhile, other measures to boost metabolic efficiency, such as drinking beet juice, drafting behind another runner, or doing plyometric exercises can also add up to boost speed.

For those at the upper end of the competitive spectrum however, the new paper elucidates something many intuitively know already: The faster you are, the harder it is to get faster.

Since the introduction of the 4% shoe, the authors note, the marathon world record has only improved by a relatively small 1.03 percent.

Shalaya Kipp, left, conducts a treadmill test in the Locomotion Lab at the University of Colorado Boulder. (photo: CU Boulder)

Lower leg pain and injuries have long been a problem for runners, but research at Oregon State University-Cascades has shown that one type of running shoe may increase such risks for some runners.

Researchers in the Functional Orthopedic Research Center of Excellence (FORCE) Lab compared the biomechanics associated with “maximal” and “neutral” running shoes in tests with female runners. The study concluded that runners experienced a higher impact peak and increased loading rate with the “maximal” shoes. Increases in both factors are associated with a greater likelihood of injury, such as plantar fasciitis and tibial stress fractures.

The study was published in The Orthopaedic Journal of Sports Medicine and is believed to be the first rigorous analysis of impacts associated with maximal shoes.

Maximal running shoes feature increased cushioning, particularly in the forefoot region of the midsole, and have gained popularity since being introduced in 2010. More than 20 varieties of maximal shoes are on the market.

Runners wearing maximal shoes, the researchers wrote, have reported feeling the extra cushion after running two to three miles. As a result, the researchers did not expect to find increases in impact peak or loading rate in runners wearing maximal shoes.

In the FORCE Lab study, researchers evaluated the impacts on runners’ feet and legs before and after a simulated 5 000 meter (about 3 miles) run on a treadmill. Each subject wore a neutral running shoe (New Balance 880) for one test and then, after a seven to 10-day waiting period, repeated the procedure with a maximal shoe (Hoke One One Bondi 4). In each test, 3D movements and forces were measured by monitoring reflective markers placed on the runners’ shoes and legs and by having the subjects run over a “force plate” that recorded the forces being applied as the runner’s foot hit the surface.

The study also evaluated the degree of “peak eversion,” the outward turning of the foot, a factor associated with injury risk. The researchers found no difference between the maximal and neutral shoes.

Maximal shoes are becoming very popular, but without controlled studies, clinicians have been unable to make science-based recommendations to runners.

Photo by Rob Kerr / OSU Cascades FORCE Lab running shoe research with Christine Pollard