How to Get Faster: The Science of Speed Training

On the home page of Aston Martin's website sits a line that has nothing to do with football and everything to do with it: "You're only as fast as your brakes." Speed coach Les Spellman, who has personally trained more than 100 professional athletes, found that sentence and built a career around it (14:43). His claim is that the ability to stop, not the ability to go, decides who survives in a sport that is, on close inspection, a four-hour sequence of collisions avoided.

Spellman opens by knocking down a stubborn myth: that speed is fixed at birth. He compares it to strength. Nobody doubts that progressive overload in a weight room makes a person stronger, yet people assume sprinting speed is just genetic luck. His counter is simple: most people have never once run at full, intentional effort (03:10). Add in force production, the ability to produce that force quickly, and symmetry between left and right sides, and, over time, a slow athlete gets faster. He has watched average high school kids reach the same 21 to 22 miles per hour that NFL "Next Gen Stats" flag as elite in-game speed (04:12).

But raw speed, it turns out, predicts less than expected. Spellman pulled the numbers on every NFL receiver who has gained more than 5,000 career yards. Only one of them ever ran the 40-yard dash in under 4.3 seconds, a time regarded as blazing (10:54). The bulk of them ran between 4.4 and 4.59 seconds (06:24). The fastest players in football are not, as a rule, the most productive ones. That gap is the whole premise of the episode: a 40-yard dash measures the engine, and football, rugby, and basketball all reward the brakes.

Learning to Brake

Deceleration research is newer and smaller than acceleration research, which is part of why Spellman says most training programs ignore it. He points to the work of researcher Damian Harper, who found that the forces an athlete absorbs while stopping can reach four times body weight, both vertically and horizontally (43:05). A hard first braking step cuts an athlete's momentum by about 25 percent, and by the third step the athlete has shed roughly half of peak speed (43:30). None of that shows up to the naked eye. What a spectator notices is the final, sharp foot plant before a cut, not the three quiet steps of braking that made the cut possible.

That blind spot has safety consequences. When an athlete tries to decelerate and change direction on the same foot contact, instead of braking first and turning second, the stress concentrates in one place.

"Directional change and deceleration on the same contact is how a lot of people will tear their ACL." — Les Spellman [46:58]

Spellman treats agility, change of direction, and deceleration as three separate, stackable skills rather than one blur called "quickness." Change of direction is pre-planned, like running a cone drill. Agility adds a decision, reacting to a defender or a ball, which raises the intensity because the athlete has less time to respond (36:10). A tennis player gives away how specific this gets: because a tennis court surface allows sliding, a single step can cut a player's speed by 40 to 50 percent (38:46), while a football player, who cannot slide the same way, needs three or four steps to do the same braking.

Rebuilding the Weight Room

Spellman's second argument is that the weight room has been misunderstood as a place for loading bars, when its real job is producing force in whatever form gets an athlete there fastest. A depth drop off a 42-inch box, which uses gravity rather than a loaded bar, produces significantly more force than a heavy back squat (101:41). That reframes exercise selection: instead of asking how much weight is on the bar, Spellman asks whether an exercise builds high force, fast force, or symmetrical force.

"We're thinking of the weight room as a force center, and if we wanna produce high forces, fast forces, and symmetrical, our exercise selection is now gonna be based around force." — Les Spellman [104:03]

Recovery gets the same treatment. The day after an NFL game, Spellman does not give athletes a full day off. Instead they walk on a treadmill at an 8 percent incline and 3 to 3.5 miles per hour while wearing blood-flow-restriction cuffs, a compression tool that partially restricts blood flow to the limbs during low-intensity movement, cycling five minutes on and three minutes off for three or four rounds (30:06, 31:49, 32:13). He is candid that the fancier recovery tools his teams tried, hyperbaric chambers, IV drips, expensive light beds, did less for performance data than consistent bedtimes, morning sunlight, and that basic walking protocol (34:16).

One of the more pointed corrections in the episode targets a cue almost every young athlete has heard: stay low when you sprint. Spellman argues this is close to the worst advice a coach can give, because compressing the torso forward kills the athlete's ability to extend the hip, which is the primary driver of acceleration (75:58).

"The worst cue you could tell somebody is stay low. Project your body up and out like a rocket." — Les Spellman [75:58]

Elite sprinters do the opposite of staying low. Their torso rises a little with every step, and top Olympic sprinters keep rising and accelerating for 16 to 18 steps, covering roughly 30 meters, before reaching an upright position (77:40). An average high school athlete, by contrast, is usually upright after six to eight steps, so coaching that athlete to mimic Usain Bolt's extended low drive phase works against their own mechanics.

Peak speed itself has a cost that Spellman learned the hard way. He used to test athletes for top speed the week before the NFL Combine, only to watch them run faster in that testing than they did at the Combine itself. The reason is recovery time: once an athlete crosses roughly 95 percent of personal max speed, the nervous system needs about two weeks to "swing back" and repeat that effort (120:15).

"If you hit those percentages above 95%, I've found that it takes about two weeks to swing back to get to that point again." — Les Spellman [120:15]

That finding reshapes how he schedules a season. In the off-season, he builds two-week blocks that let an athlete hit a new top speed and recover before trying again. Once the season starts, the goal shifts to maintenance: a weekly dose of 90 to 95 percent of max speed, with true maximal efforts saved for the off-season (119:12).

The same logic of windows shows up in his youth data, drawn from what he says is a database of 1.2 million speed tests spanning ages nine to 65 (127:07). Boys and girls run at similar speeds until about age 12, when rising testosterone widens the gap; girls then plateau until around 14, when their own jump appears (124:34). Spellman's practical advice for parents is almost anti-coaching: resist the urge to correct a young athlete's form, because an awkward stride is often just a growing body, and over-teaching technique lowers the intensity of the session and the hormonal benefit of simply running hard (122:42).

For the far more common audience, the weekend marathoner or masters athlete who wants to shave minutes off a race, Spellman's advice has little to do with sprint mechanics. He argues that the thing most adults lose with age and desk work is the ability to extend the hip, quickly and with force, which is the engine behind every stride.

"Most adults lose their ability to extend their hip, and extend their hip far, extend their hip fast, and with force." — Les Spellman [131:46]

His fix is unglamorous: hip mobility work, split squats instead of only bilateral lifts, and a short, fast sprint worked into the warm-up before a slow run, rather than any attempt at full sprint training (131:46). It is the same idea that runs through the whole conversation, scaled down. Speed is not one gift handed out at birth. It is an engine, a set of brakes, and a steering system, and for almost everyone, the brakes are the part nobody ever thought to train.