Tom Tellez' 100m Sprint Phases

The best sprinters in the world are not only the first to the finish lines but they also the best in terms of utilizing the best way of executing the sprint races. This is called racing strategy. The racing strategy relies on the specific requirement, that is the physiological parameters that governed the different sprint distances.

No one would ever sprint at maximum speed from the start to the finish line in the 100m dash. The top speed would be reached at 50 - 70m and from here the sprinters would attempt to maintain the velocity with the aim of reducing the degree of deceleration.

Several coaches have advocated different way or strategy of executing the century dash. In 1984, Tom Tellez and Doolittle detailed a breakdown of 100m race based on specific contributions of different physiological requirements, as follows:

• Reaction Time - 1%
• Block Clearance - 5%
• Acceleration - 64%
• Maintenance of Maximum Velocity - 22%
• Lessened Degree of Deceleration - 18%

In sprint races, results are always decided by a small margin. Regardless of ability, if one wishes to maximise sprinting potential the training should focus on the phases (above) that entail specific phases or strategy. This will be discussed briefly, in a practical point of view.

Block Setup

• Tellez and Doolittle suggest 90 degrees of front knee angle and 135 degrees of rear knee angle.
• This can provide an effective clearance or the first step out of the block (due to a greater horizontal velocity).
• Rearfoot placement using the pedal that provides lower degrees of rear knee angle (e.g. 90) may also provide a good clearance - but this requires a greater "timeframes", therefore the time to produce the horizontal velocity.
• The later recommendations advocate 100-110 degrees and 120-140 degree of the front and rear knee angles, respectively.

Phase 1 - REACTION 

• Quick reaction to the "gun"
• To achieve this, "set position" should be in the best position that can yield an effective action during the next phase (clearance) - see above.
• Ideal reaction times can range from 0.100 - 0.150s (100m), 0.130 - 0.180s (200m), and 0.160 - 0.230s (400m). A reaction time of less than 0.100 is considered false start.

Phase 2 - BLOCK CLEARANCE

• Block setup, set position, and clearance are the integral keys to an efficient block clearance.
• This phase requires an extremely fast and powerful first step out of the blocks, which demands quick arms "forward" and  "backward".
• The contact time (first step) is around ~0.17s.
• Horizontal velocity during the first step is around ~4.5 m/s.
• The total force exerted on the front pedal is higher than the rear one (~1100 N vs ~900 N for ~10.6 sprinters).

Phase 3 - ACCELERATION

• Increase the rate of speed, increase over time. The first three steps can bring the average velocity up to 7m/s.
• Body positioning that can allow an efficient force application is crucial.
• The body is positioned in a forward lean, to enable force exertion "down" and "back".
• Sprinters must aggressively attack and leave the ground.
• The orientation of force application (technical aspect) that influences the horizontal velocity is crucial.
• Fast and aggressive arm swings.
• In top athletes, the average velocity will gradually increase to 12.5 m/s (or 12.3 m/s fo 10m segment), 11.7 - 11.8 m/s for most of world-class athletes. The maximum velocity phase is reached once the athlete achieves these velocities.

Phase 4 - MAINTENANCE OF MAX VELOCITY

• The point of maximum velocity depends on athlete's ability to accelerate.
• The transition from acceleration to maximal velocity can be dictated by the velocity of speed; velocity increases (accelerate) and velocity stagnant (maximum speed).
• The posture is upright and tall.
• Leg movements in front of the body, little bit looks like the "piston" fashion.
• The contact of the ground is slightly in front of the centre of mass, but not excessively as it can create braking force.
• Effective changes of muscle actions, from eccentric (downwards) and concentric (upwards)  are crucial, to provide high force on the ground, in a minimal time (fast contact time), typically around 0.08-0.09 in top sprinters and 0.09-0.10 in lower level athletes, and followed by an immediate propulsion.

Phase 5 - REDUCTION (LESSENS) OF DECELERATION

• Once the maximum velocity is reached, it is important to maintain the velocity.
• Carl Lewis said he was able to maintain the top speed for 1 second only (personal communication, Dec 2010).
• Usain Bolt may be able to maintain it for 1-2 seconds.
• Therefore, the speed endurance work, as well as technical skills, are important n order to lessen the degree of deceleration. 

What are the conclusions from here?

Giving a complete conclusion from a "short" article is not objective. However, there are things that must be taken into consideration. 

High level of strength (e.g. squat 1.8 - 2.5 bodyweight) can help the high force generation. Not only strength and how much force, but how much force you can produce during the minimal time of ground contact and use it for propulsion is important (rate of force development or reactive strength). Hence, maximal strength, reactive strength, explosive strength type workouts such as 4 sets x 3-5 reps x half squat, depth jump, bounding and so on is crucial. The upright body position (mid-race to finish) demands a very fast muscle actions (stretch-shortening cycle), where your maximum strength in deadlift may provide limited contribution but the specific work predominantly vertical force direction such as the power clean, snatch, backward throws, and reactive tasks such as drop jump are preferable.