Your Achilles tendon, named after the hero of the Trojan War and the greatest of all Greek warriors in Greek mythology, is the strongest tendon in your body. Your Achilles tendon, which connects the calf muscle to the heel bone, stores energy when your foot lands on the ground, like a tight rubber band when stretched (potential energy), and gives back that energy at push-off (kinetic energy), helping to propel you forward. The better your Achilles tendon is at doing this, the better your running economy. Next time you go to the zoo, look at the Achilles tendons of jumping mammals, like kangaro ..read more

Running a marathon as fast as you can takes a long time to recover from, more than people realize, in large part because it causes a lot of muscle fiber damage. Even after 4 weeks after a marathon, damage is still present. My guidelines for how to recover and return to running after a marathon. * Immediately after completing marathon: Celebrate and drink water or a sports drink with sodium * Within 30-60 minutes post-marathon: Continue celebrating; get off your feet; consume simple carbohydrate (up to 0.7 gram per pound body weight); drink water or a sports drink with sodium * First 24-48 hour ..read more

Many endurance sports nutritionists claim that runners should spare their limited store of carbohydrate by trying to rely on fat for as long as possible, and possibly by becoming “fat adapted.” However, marathon runners can actually run faster by relying on carbohydrate for as long as possible in the race. As was first discovered more than 100 years ago, scientists August Krogh and Johannes Lindhard in 1920 found that the amount of energy derived from the metabolic consumption of oxygen depends on whether fat or carbohydrate is the primary source of carbon fuel. More energy is released for a g ..read more

Ever been told that running in the heat is like running at altitude? Haha. It’s not. The reason why you run slower at altitude is because of less oxygen delivery to skeletal muscles because of the lower partial pressure of oxygen in the air. The reason why you run slower in the heat is because of an increase in body temperature, which negatively affects the central nervous system and decreases blood pressure. You also lose a lot of water through sweating in an attempt to cool yourself and regulate body temperature, which reduces blood volume and thus stroke volume of the heart. The physiologic ..read more

I once dated a girl who had a thing for my calf muscles. Seriously. Calf muscles. She may have been on to something. Did you know that the energy cost of calf muscle contraction in highly trained runners is nearly 25% of the total metabolic cost of running? In recreational runners, it’s 40%. That’s a lot of energy being used by your calf muscles. Why do your calf muscles use so much energy? Well, think about what they have to do. They have to plantarflex your foot so that you apply force to the ground and propel you forward with each step. If you can decrease the amount of energy your calf mus ..read more

SAN DIEGO, CA – REVO₂LUTION RUNNING, the leading running certification program for coaches and fitness professionals, today announced its partnership with the International Sports Sciences Association (ISSA), the world leader in fitness education and certification. With this partnership, ISSA owns a minor stake in the company and adds to its impressive product line, offering the course on its website.   “We’re thrilled to partner with ISSA, which shares in our commitment to the industry and adds strategic and operational value,” said Jason Karp, PhD, MBA, creator and CEO of REVO ..read more

I went to Tambach track overlooking the Great Rift Valley in Kenya to do VO₂max intervals at 6,400 feet. Since the Kenyan athletes don’t typically do intervals on Mondays, it was nice to have the track all to myself. The defining characteristic of altitude is a lower barometric pressure, which keeps decreasing the higher up you go. As a result, the partial pressure of oxygen in the air is reduced, resulting in less oxygen entering your lungs with each breath. The result is that you run slower at altitude than at sea level. If you do all your altitude interval workouts at slower paces than at s ..read more

Speed-type distance runners, who have a generous amount of fast-twitch A muscle fibers, may benefit more from a high volume of interval training to improve endurance compared to endurance-type runners. Running many weekly miles at a low intensity doesn’t do as much for speed-type runners. Endurance-type distance runners, on the other hand, get a lot from running many weekly miles at a low intensity, because the slow-twitch muscle fibers love that kind of work. When planning your training volume and intensity, always remember to train to your strengths. For example, if both a speed-type runner ..read more

Today marks 9 weeks of living in Kenya. Here’s what I know for sure: 1. When you hang dry cotton T-shirts and underwear after washing them, they dry stiff, as if they have been starched. I miss fabric softener.   2. There is a lack of scientific and individualized training in Kenya, which makes the athletes’ performances even more impressive, yet speaks to the potential here.    3. The athletes don’t eat much food because they have no money to eat, which makes the athletes’ performances and ability to run so much and so hard even more impressive, yet speaks to the potential here ..read more

Running technique has a lot to do with the angles at which the runner’s legs and feet strike and push off the ground. When your foot lands on and pushes off the ground, it applies a force to the ground. As Isaac Newton taught you in high school physics class, for every action there is an equal and opposite reaction. The ground applies a force to your foot when it lands on the ground, throughout the stance phase, and when the foot pushes off the ground that is equal in magnitude and opposite in direction to the force applied by your foot. This is called the “ground reaction force.” Running is a ..read more