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Thursday 18 March 2010

Speedendurance.com

From the Archives: Maximal Speed and Deceleration

Posted: 17 Mar 2010 09:00 AM PDT

43 years ago today…

John Smith of HSI once said the goal of a 100 meter performance is to ELIMINATE the Negative Acceleration Phase. Another term is deceleration. Everyone decelerates in a 100m.

Even Usain Bolt decelerates, as seen in his splits, though he reaches his top speed well past 60 meters.

When Carl Lewis decelerates, it appears he is speeding up as others are decelerating at a rate greater then him.

The topic of maximal speed and deceleration have been around for decades.

Here is an old clipping from TIME Magazine, March 17, 1967.

Just for a comparison, Tommie Smith's maximum stride length was 2.71m (8ft 11in) compared to Usain Bolt's 2.95m. Tommie is 6 feet 3.5 inches tall, slightly under Usain Bolt's frame at 6 ft 5 in.

A lanky (6 ft. 3½ in., 167 Ibs.) Negro who wears sun glasses "for personality" and is so relaxed that he often catnaps for ten or 15 minutes before a race. Smith is called "Jet Gear" by rival sprinters—because of his huge stride (8 ft. 11 in.) and incredible acceleration. "Other sprinters reach their top speed at 75 yds, and then decelerate," says his coach, Lloyd ("Bud") Winter. "Tommie is still accelerating at the end of 100 or 220 yds. He can sustain a speed of 26 m.p.h."

For a relative look on how fast 26 mph is, or 42 kph, see http://speedendurance.com/2009/08/30/usain-bolt-tyson-gay-broke-the-44-kph-speed-limit/

When will we see 30 mph?