04 Jan The Keys to Running More Efficiently
The Top Keys of Running Biomechanics 
Six time Ironman Champion Dave Scott lists several keys to proper running form. They are as follows:
- Head looking straight forward
- Shoulders relaxed and low, arms should swing from the shoulders
- Elbow flexion of 80-90 degrees
- Hands come up to lower breastbone, arms should not cross midline.
- Pelvis tucked under hips
- Avoid Heel strike
- Foot lands aligned with chest, directly under the hips.
I would add that there should be no bounce in your stride, pelvis and head remain fairly level the entire time. When you watch elite runners, they have good shoulder and upper torso rotation, keeping their elbows at their side. Most of the arm swing is directed at moving their body in a forward direction, rather than bouncing up and down as many amateur runners do. It is important to note that elite runners will have a faster cadence, but a relatively short stride. The do not over stride, but due to higher cadence, they cover more ground in a shorter time. Key Points: 1. Good Posture Forward lean should come from ankles, do not lean forward at the pelvis of hips. The lean is subtle. 2. Lean from the ankles 3. Land on midfoot. The foot should strike the ground directly under the hip. If the 3 steps are done correctly:
- Head should be level
- Vertical motion should be minimized
- Legs should “flow” underneath you.
Cadence can be measured by how many times the right or left foot strikes the ground in one minute. There is a magic number for cadence and it is fairly consistent across elite runners, regardless of age or gender. On flat course it is 85-95, with slowing to 60-65 uphill, and speeding up to 100+ downhill. I recommend a less cumbersome way is to count the number of foot contacts in a 20 second interval. On a flat course that would be around 28-31 foot strikes for elite runners. A good rule of thumb is to shoot for between 24-28 for non elite runners. Any less than 24 and you are likely overstriding. An interesting note for triathletes for Bike-Run transitions A French study on the effect of bike cadence on run performance. In the study 8 experienced triathletes completed three bike-run sessions, in each session they had them cycle for 30 minutes at 90 % of lactate threshold. They then quickly transitioned to a run to fatigue at 85 % max velocity. They varied the cadence for the last 10 minutes of each bike session. (1) session they pedeled at a freely chosen cadence (2) at a cadence 20% higher than #1 and (3) at a cadence 20% lower than #1. For example # 1 was at 90 rpm, #2 at 108 rpm, and # 3 at 72 rpm. They found that the lower cadence group had a 37% increase in the time to exhaustion than the freely chosen cadence group. This is contrary to another study out of Colorado State University that studies thirteen experienced triathletes who completed 3 bike-run sessions on 3 consecutive days. Each rode for 30 minutes at high intensity and then ran for a 3200-meter time trial. As with the French study, they only varied the cadence, however they rode the same cadence for the entire 30 minute ride. One ride was a freely chosen cadence, one was 20 % higher and one was 20% lower cadence. They found that the high cadence bike(100-110rpm) were followed by run times nearly one minute faster than the freely chosen cadence. Most likely it is up to you to determine which bike cadence gives you the best results on your run. 1. Vercruyssen, F et al. 2005. Cadence selection affects metabolic responses during cycling and subsequent running time to fatigue. Br J Sports Med 39(5):267-72. 2. Gottschall JS et al. 2002. The acute effects of prior cycling cadence on running performance and kinematics. Med Sci Sport Exerc (34(9):1518-22. Millet GP, Vleck VE, Benltey DJPhysiological differences between cycling and running: lessons from triathletes. Sports Med. 2009;39(3):179-206