Expert Running Insights from REN
Learn from elite coaches who have trained champions. Practical advice to improve your running and reach your goals.
Why Individual Athlete Profiles Are Essential
Understanding the unique physiology behind every marathon time
Two runners with the same marathon personal record can score completely differently at shorter distances. This is because marathon performance depends on multiple physiological variables. Every runner essentially has their own profile.
Michel Butter
Elite Marathon Coach
Should I Always Train in Carbon Shoes?
The pros, cons, and smart strategies for using carbon plate technology
Since the emergence of carbon shoes in 2016, the running world has changed dramatically. Where personal records used to stand for years, they were suddenly being broken at a rapid pace. Are carbon shoes only for top athletes, or can recreational runners also benefit?
Michel Butter
Elite Marathon Coach
Matching Energy Intake to Training Load
Eat according to your effort, not out of habit
Many athletes eat roughly the same thing every day, regardless of whether they have a heavy training session planned or just a recovery run. However, your energy consumption varies greatly, and your carbohydrate requirements in particular fluctuate depending on the duration and intensity of your training sessions.
Guido Hartensveld
Performance Coach
Fatigue during a race
More than just tired legs
Every runner knows that moment in a race when everything starts to feel harder. Your legs become heavy, your pace threatens to slow down. But fatigue is more than just tired legs—it's a complex interplay of physical and mental processes.
Guido Hartensveld
Performance Coach
Critical Speed
Why training at the right intensity is crucial
Critical Speed (CS) is the pace at which a runner can just maintain their metabolism. It is the maximum speed at which oxygen uptake, energy consumption, and metabolic byproducts remain in balance.
Guido Hartensveld
Performance Coach
Why your GPS is wrong
The Jones Counter is always right
You know how it is: you run a 10 km race, cross the finish line, press your watch... and see 9.8 kilometers. But who actually determines what the correct distance is? And why isn't it your watch?
Guido Hartensveld
Performance Coach
Setting smart goals
Combining outcome, learning, and process goals
Running is more than just a sport for many—it's a way to clear your head, challenge yourself, and grow. Whether a beginner or training for a marathon, goal-setting provides direction and motivation.
Guido Hartensveld
Performance Coach
Peaking on race day
How to get the best out of yourself on the big day
Race day: the moment where everything comes together. Months of training and preparation lead to one race. But peaking at the right time isn't luck—it takes structure, realism, and mental focus.
Michel Butter
Elite Marathon Coach
More Articles Coming Soon
Our coaches are working on new insights to help you improve your running performance.
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