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Why Middle and Long Distance Runners Should Utilise the Weights Room More

Apr 03, 16 Why Middle and Long Distance Runners Should Utilise the Weights Room More

Part One of this blog is to explain what determines running velocity, while Part Two, will explain how lifting weights can improve our running velocity, running economy and reduce the likely hood of overuse injuries (volume based injuries).

Endurance running performance is reliant on much more than just physiological (fitness) factors such as VO2 max and lactate threshold. As all races are won by the fastest athlete, research has now shown that other factors such as the running velocity at VO2 max (vVO2 max) and endurance specific muscular power tests like maximal aerobic running velocity (vMART) have a greater effect on a race outcome. These new factors have two things in common: efficiency of locomotion to preserve energy usage and the velocity at which aerobic based running can be sustained.

For many years, proper strength training has been avoided by endurance athletes for reasons unknown, maybe through fear of increasing body mass or that it will slow them down. However, in recent years science has proven, time after time, that research driven resistance training or concurrent training (including resistance training into an endurance programme) hold the key to success in endurance sports as shown in Table 1.

Table 1 shows the research investigating the use of various forms of resistant training to improve running and triathlon performance.

That being said, how do we increase our vVO2 max or vMART? We need to be able to run faster with less energy usage. This has led running coaches down the wrong path on how to improve running velocity, physiology (fitness) determinants aside. In biomechanics there are two sub divisions: kinetics and kinematics. SR and SL fall into the kinematics sub division which DESCRIBES motion. However, understanding the kinetics, which look at the forces that CAUSE motion (Ref 2) will aid us to improving SR and SL and therefore vVO2 max or vMART.

Overcoming the force of gravity is key in running; if we cannot overcome gravity’s downward acceleration we cannot walk, sprint, jump or do anything. Unfortunately, as our running velocity increases, ground reaction force (GRF) increases due to the downward acceleration of our centre of mass (COM; but the time we have in contact with the floor decreases as our COM travels over the contact foot faster (Ref 4) (see figure 2). This means that we have to deal with greater forces in less time; therefore, our ability to run at increased velocities is determined by our ability to produce vertical force in shorter time frames. I’ll now explain why:

Figure 2 shows the relationship between increased magnitude of ground reaction force and reduced ground contact time as velocity increases in both competitive and non-competitive sprinters.

Stride rate is a product of rapid repositioning of the lower limbs and is determined by ground contact time (GCT – the length of time our foot spend in contact with the ground) and flight time (the time spent in flight between ground contacts) (Ref 1). When comparing the running gait of good level sprinters, Weyand and colleagues (2000) found that the faster sprinters showed no difference in flight time or repositioning of the lower limbs. However, they did demonstrate a significant reduction in GCT suggesting that SR is improved by reducing GCT not repositioning the limbs quicker. This is where a lot of running/fitness coaches misinterpret the evidence: they try to coach ‘fast feet,’ in order to reduce GCT with tools such as speed ladders. I’m not going to go into reasons why speed ladders are a bad tool, but trying to reduce GCT with fast feet for any runner is detrimental to performance. The reason better sprinters have shorter GCT is because they can deal with the increased GRF through greater lower limb muscle stiffness and turn that landing force into a push-off force, very quickly reducing GCT. Although most of this is referring to sprint ability, the point still stands for endurance running: to improve your SR you need to increase your ability to handle the increased forces upon landing in shorter time frames.

Figure 3, showing a speed ladder drill.

Stride length is largely dependent upon three variables: velocity of travel, flight time (runners undergoing projectile motion) and contact length (the distance our centre of mass travels while our foot is in contact with the ground). Flight times during maximal velocity sprinting have been shown not to differ irrespective of ability and, as athletes have a fixed limb length, unless you’re a youth runner who is still growing, contact length is relatively fixed. This would suggest that SL is determined by the runner’s velocity at take-off and flight phase (Refs 1,3). Trying to increase SL is another area where running/fitness coaches are mislead, trying to reach out with the foot. When we try to physically increase our SL, runners end up reaching too far in front of their COM resulting in a short phase of deceleration. If we apply a force to a solid object (the ground) it returns an equal and opposite force, causing deceleration (Newton’s laws) if that returning force is opposite to the direction of our travel. Therefore, if endurance runners want to improve their SL they need to improve their take-off/flight velocity which goes back to the same point: as SR increases the magnitude and rate at which you apply force to the ground you will increase SR and SL, therefore improving running velocity.

Figure 4, shows the representation of contact length with the red arrow and displacement of centre of mass black arrow.

Although I said at the top of this article that increasing SR and SL does not improve running velocity they are, however, consequences of running velocity and still need to be improved. If endurance runners want to improve their running velocity from a biomechanical stand point and improve vVO2 max, vMART, SR and SL (which I would advise), they need to increase their force (strength) capabilities during ground contact of the running gait as this is the only time we can influence the force of gravity. Moreover, as the GCT reduces as we increase velocity, we need to be able to produce the required force at greater rates of development. If we can’t physically produce the required force in the shortened time-frame our velocity of travel is limited. The reason I advise runners to improve their running from a biomechanical stand point is that it doesn’t matter how fit you are, if you can’t handle the force demands on the ground you’re always selling yourself short. Part 2 will explain how strength and explosive training will improve our vVO2 max or vMART.

References

  1. Goodwin, J, (2011) ‘Maximum velocity is when we can no longer accelerate, using biomechanics to inform speed development.’ Prof Str and Con, 21 pp.3-9.
  2. Grimshaw, P., A. Lees., N. Fowler, & A. Burden, (2006) Sports and Exercise Biomechanics, New York, NY: Taylor and Francis group.
  3. Weyand, P. G., D. B. Sternlight, M. J. Bellizzi & S. Wright, (2000) ‘Faster Top Running Speeds are Achieved with Greater Ground Forces Not More Rapid Leg Movements’, J of Appl Phys, 89 (5) pp.1991-1999.
  4. Wild, J., N. Bezodis., R. Blagrove, & I. Bezodis, (2011) ‘A biomechanical comparison of accelerative and maximum velocity sprinting: Specific strength training considerations,’ Prof Str and Con, 21 pp.23-36.
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