Do Super Shoes Make You Faster at a Cost?
Plus—Carbs in the heat; female runner durability; VO2 max and mortality, the G.O.A.T runner; and an essay on Ethiopian running culture.
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Do Super Shoes Make You Faster at a Cost?
Super shoes have become one of the strangest training decisions in running. On the one hand, they are clearly fast. The combination of highly resilient foam, tall midsoles, and stiff embedded plates can improve running economy and make race pace feel just a little more forgiving. On the other hand, almost every runner now has a story: the friend who started doing workouts in plated shoes and suddenly had calf issues, foot pain, or a bone stress injury that seemed to come out of nowhere.
That does not mean super shoes are dangerous. But it does raise the question of when these shoes do change how we run, where does that stress go?
A new study looked at exactly that question in elite distance runners. The researchers had 23 healthy elite runners, 11 women and 12 men, run in three different shoe conditions: a neutral shoe, a lightweight responsive foam shoe, and an advanced footwear technology shoe with highly cushioned foam and a stiff embedded plate. The runners tested each shoe in randomized order at three self-selected speeds: training effort, tempo effort, and 5K race pace. During each condition, the researchers measured movement and force patterns that have previously been associated with bone stress injuries.
In the advanced footwear condition, runners showed a lower cadence, meaning they took fewer steps per minute. Lower cadence often goes along with longer strides or slight overstriding, which can increase loading demands on the body over time. The researchers also found more inward collapse of the arch/rearfoot compared with the neutral shoe, another mechanical pattern that has been linked with bone stress injury risk. These changes were described as small, but small changes repeated thousands of times per run can matter when an athlete is stacking workouts, long runs, and high weekly mileage.
But there was also a potentially protective signal. In the super shoes, runners pushed off less with their ankles. That suggests the shoe may reduce demand on the ankle plantarflexors, including the calf-Achilles complex, during propulsion.
This is the part that makes the interpretation more complicated. Super shoes may not simply increase or decrease injury risk; they may redistribute load. Less ankle demand could be helpful for some runners, while altered cadence and greater rearfoot motion could shift stress elsewhere, including toward the bones of the foot or lower leg.
What this means for runners
If you race in plated shoes, you probably need some exposure to them in training so race day does not become a brand-new mechanical stimulus. But I would be cautious about making them your everyday trainer, especially during high-volume blocks or when returning from injury. Rotate shoes, introduce plated models gradually, and pay attention to early warning signs in the foot, shin, calf, and Achilles. The key idea is that super shoes may help you run faster by changing how load is distributed, but your bones, tendons, and muscles still need time to adapt to that new loading pattern.
Do Carbs Still Work When It’s Hot?
Racing or training in the heat has a way of making every normal endurance rule feel a little shakier. Paces that usually feel controlled suddenly feel too ambitious. And fueling (which is already part science and part personal experiment) gets even more complicated when your gut is bouncing and your sweat rate is climbing.
Do carbohydrates still help endurance performance in the heat, or does heat stress change the equation?
A new systematic review looked at carbohydrate supplementation during endurance exercise in hot environments. The researchers synthesized nine randomized crossover studies. In practice, these were all lab-based cycling studies performed in environmental chambers between 80–95 degrees Fahrenheit (27 to 35 degrees Celsius), with humidity ranging from 20% to 78%. That is important right away: this review is highly relevant to endurance athletes, but it is not directly a running review.
The carbohydrate strategies varied a lot. Some studies used glucose or maltodextrin, others used multiple transportable carbohydrates like glucose, sucrose, fructose, or maltodextrin-fructose combinations, and one used sago. Intake rates ranged from a very low 14 grams per hour to an extremely high 140 grams per hour. Exercise trials lasted roughly 50 to 152 minutes, with performance measured through either time-to-exhaustion tests or time trials.
The results were mixed, which is probably the most honest answer here. Five studies found performance benefits from carbohydrate supplementation in the heat, while four found no clear effect. In the positive studies, carbohydrates improved time to exhaustion by 13.4% to 19.3% and improved time-trial performance by 3.3% to 12.7%. That sounds impressive, but the picture gets messier when you look closer. Some of the biggest benefits came from time-to-exhaustion tests, which are useful in the lab but less reliable than real-world time trials.
The bigger physiological question is whether carbohydrate intake in the heat actually changes fuel use. Heat stress can increase glycogen breakdown, which creates the theory that athletes might need more carbohydrate when racing hot. But in this review, most studies did not find major differences in respiratory exchange ratio (a marker of relative fat and carbohydrate use during exercise) or carbohydrate oxidation between carbohydrate and placebo (no-carb) conditions. Taking in carbs did not consistently appear to reduce the body’s reliance on stored carbohydrate. That does not mean fueling is useless; it means heat may create a more complicated metabolic environment where hydration, thermoregulation, gut function, and central fatigue all compete with simple “more carbs equals more performance” logic.
The gut may be the hidden variable. Only two of the nine studies actually measured gastrointestinal symptoms, which is a major limitation because heat is notorious for making the gut more fragile. One study found more nausea, fullness, and stomach upset with a 12% glucose drink providing about 100 grams per hour compared with a 6% drink and placebo. Another found greater fullness with a 16% maltodextrin-fructose drink at 90 grams per hour. The review also noted that one study using a very concentrated 14% carbohydrate drink, equal to roughly 140 grams per hour, produced worse performance on average, which may have been related to gut distress, even though GI symptoms were not measured.
Hydration and body temperature did not seem to be strongly affected by carbohydrate intake overall. Most studies found no meaningful differences in hydration markers, core temperature, or perceived exertion between carbohydrate and placebo.
What this means for runners
I would not take this review as a reason to fuel less in the heat, but I would take it as a reason to fuel smarter. Carbohydrates can still help, especially for longer races and harder efforts, but hot conditions make the gut less forgiving, so forcing huge carb targets without practice may backfire. The practical hierarchy should probably be: start well-fueled, prioritize hydration and sodium based on sweat losses, use carbohydrate amounts you have practiced in similar conditions, and be cautious with very concentrated drinks or aggressive fueling rates when it is hot and humid. Since all included studies were cycling-based, runners should be especially careful extrapolating the higher intake ranges, because running tends to create more gut jostling and GI distress.
Female Runners are More Durable than Males
Most runners think about fitness in terms of what they can do when they’re fresh. What’s your VO2 max? What’s your threshold pace? What can you run for a 5K, half-marathon, or uphill time trial when the legs are ready to go?
But racing rarely asks that question. Racing asks a much more interesting one—what can you still do after two or three hours of accumulated fatigue?
That’s the idea behind “durability” (a.k.a “physiological resilience”), one of the more useful concepts in endurance performance right now. It’s not just how strong your engine is at the start. It’s how much of that engine you can keep using after glycogen drops, muscles get beat up, stride mechanics shift, and perceived effort starts climbing. A new study asked whether male and female runners differ in that quality.
Researchers studied 11 highly trained female trail runners and 11 highly trained male trail runners who were matched by performance level using International Trail Running Association rankings. The runners completed three lab visits: a graded exercise test, a fresh 12-minute uphill time trial, and then a 3-hour treadmill run at moderate intensity with another 12-minute uphill time trial inserted every 60 minutes. During the prolonged run, the athletes consumed 90 grams of carbohydrate per hour and drank water as desired, while the researchers measured physiology, biomechanics, perceived exertion, and the strength of muscles in the thigh and surrounding the knee.
The women held up better. After three hours, female runners had only a 1.1% decline in uphill time-trial speed, while male runners slowed by 9.9%. That is a massive difference in durability. This was not because the women were working less hard in the time trials; heart rate, perceived effort, and peak oxygen uptake during the time trials were broadly similar in how they responded across the protocol. Instead, the difference seemed to come from greater metabolic and neuromuscular resilience.
During the 3-hour steady-state run, both groups shifted toward greater fat use over time, but the shift was much larger in men. By three hours, carbohydrate oxidation had dropped by 29% in male runners versus only 9% in female runners. Respiratory exchange ratio also fell more in men, suggesting a bigger move away from carbohydrate metabolism. During the repeated uphill time trials, the same pattern showed up again: men had larger drops in carbohydrate oxidation, larger increases in fat oxidation, and bigger reductions in peak blood lactate.
That lactate finding is important. In a hard uphill effort, peak lactate is partly a sign that the runner can still access high-intensity carbohydrate-driven energy production. By the final time trial, male runners showed a 53% drop in peak lactate, compared with a 27% drop in females. That suggests the men were losing some ability to hit the same high-intensity metabolic gear as fatigue accumulated.
Muscle strength also declined more in men, with males showing an 18% reduction after two hours, while females were essentially unchanged at that time point. Meanwhile, running economy worsened similarly between sexes, and both groups made fatigue-related biomechanical adjustments: longer ground contact time, reduced stride length, and lower leg stiffness. In other words, the durability advantage in women did not seem to come from some radically different stride pattern. It looked more like better preservation of the metabolic and muscular systems that support performance late in a long effort.
There is one big caveat: the study matched runners by duration, not distance. Because the men ran faster, they covered more total distance during the protocol: about 26 miles versus 22 miles for women. They also expended more energy relative to body mass. The researchers tried to account for this statistically, and the findings largely held up, but this still matters. If the study had matched distance instead of time, the gap might have been smaller.
What this means for runners
The practical takeaway is that durability deserves more attention than fresh fitness. A runner with a great threshold test or fast standalone workout may not be the runner who performs best after two or three hours, especially on hilly terrain. For everyone, one of the best ways to assess durability may be to place short, controlled hard efforts late in long runs and see how much performance, form, and perceived effort deteriorate. The race is not decided by what your physiology looks like when you’re fresh; it’s decided by what’s still available when the easy miles are behind you.
