Running economy
[7] A new method for measuring such concepts can be found with the help of the use of wireless foot-worn inertial sensors together with dedicated signal processing algorithms.
[8][9] There are a number of variables that may affect running economy: vertical motion while running, the ability of the muscles to absorb energy during the shock of landing and transfer it to push-off, biomechanical factors, technique and type of activity, fitness and training, age, fatigue, gender, race, weight of clothing and shoes, and environmental conditions.
[6] An ideal body for optimal running economy would include height slightly smaller than average for males and slightly greater for females, low body fat percentage, leg mass distributed closer to the hip joint, and a narrow pelvis with smaller than average feet.
[6] There are many physiological conditions that can affect running economy including maximal oxygen uptake, metabolic factors, tendon length, and ventilation.
Running economy has also been observed to decrease towards the end of races while core temperature, heart rate, ventilation, and lactic acid increase.
Factors that affect metabolism would be important for improved running economy so as to efficiently utilize the body’s resources.
[5] It is also preferable that a runner’s body can burn fat as an energy source under intense work loads, in addition to carbohydrates.
Other criticisms of these studies include small sample size, too few measurements to account for intra-individual fluctuations, and other factors that affect running economy.
Heavy-load strength training has been shown to increase the amount of motor neurons activated when a muscle is contracted, producing a greater force.
This reason is most commonly attributed because strength training is often associated with hypertrophy, causing an increase in muscle size, which would be disadvantageous for running economy.
At high altitudes, metabolic erythropoietin increases the production of red blood cells to compensate for the lack of oxygen.
[2] Studies have shown that running economy improves considerably when training/sleeping at high altitudes and competing near sea level.
[2] Stride length, body kinematics, kinetics, and elastic energy are biomechanical factors associated with improved running economy.
[13] A runner with a better running economy has a relatively low amplitude of their center of mass, increased swing of the lower legs during a stride (decreased angle of the back of their knee), and increased angular velocity of plantar flexion during push-off, but has a reduced range of movement during plantar flexion.
[2] Other biomechanical factors associated with better running economy includes faster rotation of the shoulders, limiting of arm motion to moderate motion, a greater angular movement of the hips and shoulders with respect to the transverse plane of the runner, and lower peak levels of force on the ground.
[2] Flexibility of lower limb and torso in trained athletes improves running economy at all speeds through increased range of movement in the hips.
[15][16][13] Cushioning has also been shown to reduce oxygen uptake and therefore running economy by providing an elastic energy storage of the downward force.
[2] The shoe cushion itself needs to be of an optimal ‘spring rate’ in order to beneficially complement the muscle movements and forces.
Recent research has shown that the addition of a carbon-fiber plate in the midsole of a shoe coupled with a springy foam benefits running economy by reducing negative work done by the metatarsophalangeal joint.
[18] Many runners were screened for the event, and ultimately Lelisa Desisa, Eliud Kipchoge, and Zersenay Tadese were chosen based on their potential.
To acquire data from each contestant, the Nike science team gave each runner GPS watches and heart rate monitors.
Additionally, they visited each runner in their hometown to analyze hydration and nutrition strategies while monitoring skin temperature and sweat rates.
Slight modifications to the athletes diets were also tested, such as having Eliud Kipchoge eat beetroot bars instead of drinking beet juice.
