Back in 2008, Galen Rupp set a record that doesn't show up on his USA Track & Field bio. He ran a workout alternating 200 meters in 30 seconds with 200 meters in 40 seconds, and completed 24 laps. The previous record for the "30-40" session, according to Oregon legend, was 18 laps by Steve Prefontaine. For a runner of Rupp's caliber, a 200 in 30 seconds (roughly mile pace) doesn't present much challenge. What makes the workout so special is the speed of the "recovery."

Even for Rupp, 40 seconds is no jog. This form of brisk recovery run is sometimes called a float workout.

By keeping the recovery quick—but below threshold—you'll maintain very high lactate levels throughout the run, without pushing it so high that you have to stop. As Krista Austin, Ph.D., a physiologist who works with elite runners, explains, the body responds by learning to move lactate more quickly out of your muscles and into your bloodstream, where it can be disposed of or reused as fuel. The payoff: You'll recover from midrace surges without slowing down.

Float workouts can include intervals ranging from 100 meters to several miles, making them a useful tool for anyone racing distances between 5-K and the marathon. The workouts repeatedly take you across your lactate threshold, which means the recovery is always slower than tempo pace. Do one float workout a week for three weeks, then scale back to doing one every two or three weeks. Here are a few ways to build your surge protection.

MONA FARTLEK
Steve "Mona" Moneghetti, a four-time Olympic marathoner for Australia, used to run this fartlek workout every week or two. By tweaking the float pace, he could focus on endurance (quicker float) or speed (slower float) at different times in his 26.2 buildup. Run the effort between 5-K and 10-K pace and the recovery at marathon pace or slightly faster.
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CANOVA K'S
Italian coach Renato Canova, who coaches top Kenyan athletes including Chicago Marathon champ Moses Mosop, uses this workout to develop endurance at marathon pace. Run it every two weeks during a marathon buildup. Be realistic about the paces corresponding to your fitness, and focus on increasing the pace of the recovery as your fitness improves.
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1000 meters at half-marathon pace, followed by 1000 meters at marathon pace. Repeat three to six times.

OREGON 30-40s
First introduced by Oregon coach Bill Dellinger in the 1970s, this workout is a rite of passage for runners. It's ideal preparation for a 5-K but can also fit into mile and 10-K preparation. Once or twice a season at most, use this workout as a mental and physical test. Don't cheat: Once you fall off pace on either the fast or slow section, you're done.
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200 meters at mile pace followed by 200 meters at 10 to 15 seconds slower than mile pace. Aim for six to eight laps.