Remember when it was de rigueur to stretch before running and over-hydrate before heading out the door? As technology advances and researchers discover more about the human body in motion, long-held fitness beliefs are crumpling. Currently before the firing squad: heart rate, aging, fueling, and footwear rules that have likely been ingrained in your psyche.
Don’t get caught on the wrong side of science. Presenting 10 running-related tenets that researchers and expert coaches have recently debunked.
1. Max Heart Rate Matters
The formula has been used for more than 40 years as a quick and easy way to determine heart rate-based training zones. Since its inception in 1970, however, it’s come under fire for its potential to be wildly inaccurate, leading athletes to seek other ways to determine how hard to push a workout, like calculating lactate threshold-based training zones.
But that hasn’t stopped a new team of researchers from trying to revamp the old heart-rate formula. Dr. Thomas Allison, program director of the sports cardiology clinic at the Mayo Clinic in Rochester, Minnesota, and his colleagues recently analyzed data from 25,000 cardiac stress tests, a procedure in which a patient exercises to maximum physical exertion while doctors monitor the heart’s function.
The researchers found that while everyone’s max heart rate goes down with age, it decreases more slowly in women. “As a result, the currently used formula overestimates the peak heart rate that younger women can reach and underestimates it for older women,” The Journal of the American Medical Association writes. The researchers propose a more accurate way to determine max heart rate is to use the following formulas:
For women: 200 – (.67)age
For men: 216 – (.93)age
Currently, these calculations only apply to people between 40 and 89 years old, as the subjects analyzed fell in that age range. The new formulas could help older athletes determine more accurate heart rate training zones, and ease frustration about hitting a max heart rate that may be unachievable.
2. A Midfoot Strike Is Best
If you run slower than a 5-minute mile, it may be most efficient to heel strike. As we recently reported, a new study published in Medicine and Science in Sports and Exercise found that rear-foot strikers are up to 9.3 percent more economical than midfoot strikers.
“With the cost of energy that a forefoot [subject] needed to run, at a fixed speed, they could be running 1 km/h faster,” lead author Ana Ogueta-Alday told Outside reporter Matt Allyn—the equivalent of dropping from a 7:30 minute mile pace to 7:00 flat.
Ogueta-Alday believes the reason for the improved efficiency stems from the increased ground contact time the study observed in rearfoot strikers. More contact time with the ground allows for more force to be applied, while also decreasing the metabolic cost of running.
Of course, that doesn’t mean mid- and forefoot strikers should abandon their ways. Several other studies, including this one from Harvard, have found that rear-foot strikers have a higher injury rate than other runners because landing on the heel generates greater impact on the body.
In sum: If you’re a heel striker and haven’t been chronically injured, there’s no need to change your ways.
3. Less is More
As the New York Times reports, last summer five separate studies presented at the annual meeting of the American College of Sports Medicine “found no significant benefits, in terms of economy, from switching to minimalist, barefoot-style footwear.”
Even more damning, the Times continues, other studies have found that wearing minimalist shoes does not toughen foot muscles to make runners more injury resistant, one of the key arguments of the minimalist movement.
For certain biomechanically blessed runners, minimalist shoes may work well. Other runners seem to have decided, with the help of scientific research or not, that minimalism isn’t for them.
Marathon wearing Vibram FiveFingers was negligible. And Runner’s World reports that minimalist shoe sales declined more than 10 percent in the beginning of 2013. “It seems this fad,” their industry source said, “is pretty much over.”
4. You’ll Peak in Your 20s
Two recent studies looked into the ages of top finishers at several different ultra-distance events. The first looked at performance in 24-hour ultramarathons held worldwide between 1977 and 2012. The annual 10 fastest men and women were 40.9 and 43 years old, respectively.
The second study, conducted by several of the same researchers, looked into performance in events ranging from 50 to 3,100 miles. Below, the ages of the fastest runners according to distance:
Distance Women Men
50 miles 35 35
100 miles 35 38
1,000 miles 43 48
3,100 miles 35 39
The researchers believed motivational and psychological factors play the biggest role in the success of older athletes at ultramarathoning. Masters athletes, they suggest, have high intrinsic motivation to run, race, and train more for self-satisfaction and improvement than prestige or beating rivals, as their younger counterparts often do.
5. Running Destroys Your Knees
Every time a runner’s foot strikes the ground, a force of about two to three times his bodyweight goes up through it. It might seem like that repetitive pounding would wear away at a runner’s knees, but studies show that doesn’t happen. In fact, researchers at Johns Hopkins School of Medicine wrote, “long-distance running might even have a protective effect against joint degeneration.”
Why? A study published in March in Medicine and Science in Sports and Exercise sought to explain why runners don’t have high risk of developing knee osteoarthritis compared to non-runners. The researchers’ conclusion: Runners take longer strides than walkers and have less contact with the ground with each step. So even though each stride has greater impact, they take fewer strides than walkers. Therefore, the impact of running and walking over a given distance is about the same.
6. Glucosamine Helps Your Joints
If you read Myth #5, you know your joints may not even need saving. But if you started taking glucosamine supplements preventatively or because your joints hurt, stop. Save your cash. Compared with a placebo, research has shown, glucosamine, chondroitin, and their combination don’t reduce joint pain, nor do they prevent osteoarthritis.
What does? Because researchers don’t fully understand the cause of osteoarthritis, they can’t detail a surefire prevention method. If you already have joint pain, the Arthritis Foundation suggests staying active and maintaining a healthy BMI are the best ways to relieve joint pain. “Losing one pound can take four pounds of pressure off your knee joints,” they write. And “strong muscles protect joints.”
7. You Can Eat Whatever You Want
This Wall Street Journal headline says it all: "Studies Show There Are Heart Risks to Devil-May-Care Diets—No Matter How Much You Run."
Being a runner, researchers stress, does not give you a free pass to live unhealthfully in other areas of your life. While being physically active has been shown to lower the risk of coronary heart disease, studies have also shown that avid runners don’t have a more favorable atherosclerotic risk profile than less active people. Atherosclerotic being a fancy word for hardening of the arteries caused by a buildup of fat, cholesterol, and other substances.
So even though you may be incinerating calories during your workouts, you need to pay attention to your diet just like everyone else to lower your risk of heart disease. The National Heart, Lung, and Blood Institute recommends eating a diet low in saturated and trans fats, salt, and sugar, and high in omega-3 fatty acids and fiber to do just that.
8. Dehydration Wrecks Performance
It’s long been held as fact that losing more than 2 percent of bodyweight to dehydration will hurt performance. But several recent studies, as well as anecdotal evidence from the world’s top runners, suggest it’s possible to lose more than 2 percent with little to no detriment to performance.
Titled “Current hydration guidelines are erroneous,” one of those studies was recently published in the British Journal of Sports Medicine. In it, researchers from High Performance Sport New Zealand explain that most dehydration studies “have been conducted in relatively windless environments (ie, wind speed <12.9 km/h), without participants being blinded to their hydration status.” Those conditions aren’t very applicable, they argue, to real race conditions.
They found weight loss of up to 3 percent did not slow down athletes (cyclists, in this case) or lower their power output. Another study found the loss of 3.8 percent bodyweight did not impact the 15.5-mile times of soldiers marching in the heat.
Finally, a 2012 study examining the drinking behaviors of elite male marathoners found that Haile Gebreselassie lost a whopping 9.8 percent of his bodyweight during the 2009 Dubai Marathon—and still won, in 2:05:29.
9. All Your Runs Need To Be Fast
“There’s a reason that Fartlek and interval training and things like that work,” says Jon Clemens, head coach of San Diego’s Milestone Track Club. “Stressing your system like that causes changes to your musculature” that will help speed you up.
That said, there are other ways to get faster. If an injury or lack of motivation are keeping you from busting out interval and tempo runs, do this instead:
Up your efficiency
“Improving running economy will help you run faster because you’re not wasting energy, for example, allowing your left leg to do something weird on your stride,” Clemens says. Plyometric exercises like high knees, butt kicks, skipping, and walking on your tiptoes will help “make you stronger and minimize excessive movement,” Clemens says. “We do these drills to make your body a tight package.”
One reason runners fall off pace toward the end of the race is fatigue causes them to run less efficiently. Staying strong will help you maintain form, which could lead to speedier finishing times.
“Running more can help you run a little faster,” Clemens says. “If you’ve been running three times a week, and you start running five times a week, you should develop the strength that’ll help you run faster.” Running hills can also help develop strength.
10. Your Long Run Must Be 20 Miles
As two-time modern pentathlon Olympic medalist and legendary running coach, Jack Daniels, wrote on Active.com, elite runners will cover 20-plus miles in 2.5 hours or less. It may take novice runners twice the amount of time to cover that distance, and therefore, they’ll suffer twice the amount of impact on the body, which could lead to race-ending overuse injuries. (This is kind of what the next line states.)
“Impact and training time contribute to overuse injury, along with a greater chance of dehydration and heat or cold stress,” Daniels wrote.
Don't worry that you won't be able to complete a 4:30 marathon if you have never run beyond two and a half hours in training. In fact, it is not necessary to train at such a high percentage of your race distance no matter what the course.
Daniels suggests going for time, not distance, to avoid overtraining injuries and burnout. For many runners, it may be wise to peg that long run at 2.5 hours, no matter how far you’ve run, rather than 20 miles.