As promised earlier in the week here is part 2 of the interview with Barry Ross. Here he discusses the “juicy” bits about his book and shows how he applies “ground breaking” (pardon the pun) research in the search for faster running.

What important research was the book based around?

Underground Secrets to Faster Running was based on the concept of mass-specific force, as noted in the Weyand study. The research showed that the commonly used equation, Speed= Stride Length x Stride Frequency did not address the main factor in high speed running. The study provided a more accurate, though odd looking, equation: Speed= Freqstep x Favge /Wb x Lc.

What it means is that during constant-speed running, the distance traveled between steps is determined by the product of the average mass-specific force applied to oppose gravity during foot-ground contact and the forward distance the body moves during this contact period.

This equation is counter to the commonly held belief that active push-off occurs at the end of stance time; that strength in relation to bodyweight is a factor in producing force during active push-off,  that faster runners swing their legs faster (turn-over rate); that horizontal force application is dominant.  None of the foregoing is true.

Your book includes an excellent method for improving mass specific force.  Briefly, what is the method and what is mass specific force?

Mass-specific force is force (relative to the runners mass) applied to the ground in opposition to gravity. Ground reaction force plates show that maximum force peaks just prior to midway through the stance time. There is no way to get around that fact! What’s being measured is force created by the runner as a falling body—Pure physics.

If “active push-off” did occur, then force plates would show the runner applying force at the end of the stance time—but virtually no force appears at that point.

The force the runner applies to the ground is to oppose the effect of gravity. For example, if you jumped off a 1.5m box, you would naturally bend your knees to absorb the shock. The amount of knee bend affects the amount of elastic energy your body can utilize for locomotion. It also dictates ground contact time. More strength allows minimization of knee bend (plus some extra bonuses) thereby reducing ground contact time and increasing running speed.
Increasing strength without increasing mass maximizes the whole process because mass is an integral part of the force created at ground contact and the force you need to apply to oppose it.

Our strength training method eliminates the effects of using a modified bodybuilding routine (where mass IS necessary). Had I used our current strength training protocol in 1967 I would have been at least as strong while reducing bodyweight gain from 20 lbs to 3-4 lbs.

How does your training advice improve the physiological mechanisms responsible for running faster?

Increasing mass-specific force reduces ground contact time as well as maximizing the runner’s use of elastic recoil created from an eccentric stretch as the runner’s mass passes over the grounded foot. Elastic recoil drives the runners leg back into the air in the same way that a super ball thrown into the ground recoils back into air (without the need of coaching, I might add!). The effect on the runner is increased knee height. That renders high knee drills as redundant at best.
As the runner increases top end speed, they also increase wind effect. Any sprinter running on a windless day will create wind effect. An elite sprinter can create wind in excess of 40 kilometers. The natural response when walking into a headwind is to lean forward to “cut through” the wind. The sprinter does the same when running, naturally. Is it worth spending training time for a non-elite sprinter to lean at the same angle as an elite sprinter? Not if you do as little as needed, not as much as possible.
 
For those people who are new to research into human locomotion and are interested in learning how to run faster what resources would you suggest?
There is a wealth of recent studies from several locomotion experts that debunk most of the misinformation created by coaches from false application of earlier works. One victim of faulty training application is Ralph Mann’s study on kinetic analysis of sprinting (Mann’s work is correct, the interpretations were faulty). First and foremost, read the Weyand study mentioned above as well as several others that are focused on high speed running. Chang and Kram have two excellent papers, “Metabolic cost of generating horizontal force during human running” and “The independent effects of gravity and inertia on running.” The former shows why the greater efficiency of the spring mass model of running identifies the reasons why bipeds and quadrupeds run the way they do; while the latter shows how easily human runners adapt sprint mechanics to even the most radical changes in conditions without the need of a “coach”.

Where do you see your work and locomotive research progressing in the future?

There is a large, and growing, body of research that is yet unpublished let alone new research that is already underway. Ken Jakalski and I have opened the door between coaches and scientific geeks a little bit wider by being proactive with the scientists—as they have been with us. Hopefully, many more in the coaching and science communities will drop the notion that the two are a volatile mix!

Many thanks goes to Barry for giving his time to discuss his works. If your interested in reading any more information regarding Barry’s work visit his website. http://www.bearpowered.com

Alan Ruddock CSCS, YCS