David Laney found his stride on the trails in 2015, kicking off the year by winning a national title at the Bandera 100K in January, and following that up with a victory at the Chuckanut 50K in March, improving upon his second-place finish from 2014. Those impressive victories aside, the Nike Trail-sponsored Laney may have shined brightest over the summer, battling to an eighth-place finish at the Western States 100 in June (a 12-place improvement from the year before) and a podium finish at the grueling 104-mile Ultra-Trail du Mont Blanc (UTMB) in August, where he placed third.

Next up for Laney: the 2016 U.S. Olympic Trials Marathon on Feb. 13 in Los Angeles. Laney qualified for the Trials with a 2:17:02 personal best clocking at Cal International in late 2014, evidence of his impressive road-to-trail versatility.

One of Laney’s key workouts for developing the fitness necessary to run a solid marathon while also being able to compete at the front of long trail races is a 5-4-3 mile progression run, which he typically does once or twice during a marathon or 50-mile buildup. The last one usually falls 5 or 6 weeks out from his goal race.

“For me, it’s a challenging but fairly controlled workout,” explains Laney, who also coaches runners at Trails and Tarmac. “The workout gives you a ton of volume around marathon pace and a ton of work at your aerobic threshold without the effort of hammering a half marathon at race pace.”

Following a 3-mile warmup at an easy pace, the workout starts with 5 miles at 10 seconds per mile slower than your marathon race pace. After completing the 5 miles, “recover” with a cruise mile that’s roughly 45 seconds per mile slower than your marathon race pace. Upon the completion of your cruise mile, run 4 miles at your marathon race pace—which for Laney equates to 5:15 per mile—followed by another cruise mile. The workout finishes with 3 miles at 10 seconds per mile faster than your marathon race pace. Cool down with 3 miles of easy running.

“The cruise miles break up the workout quite a bit and make it much easier,” says Laney. “I know I’m really fit not when I go faster on the marathon pace sections but on the cruise miles. When those feel really easy and I recover quickly I know I’m ready to go.”

Laney says the workout—which should be done on a flat or gently rolling road or bike path—can easily be modified by doing a 4-3-2 or even a 3-2-1 mile progression in place of the 5-4-3 format.

“This is a great workout because the paces and distances can be easily modified to runners of all abilities,” explains Laney. “For newer runners simply doing 3-2-1 mile progression or 4-3-2 is a great workout.”