Train for fatigue resilience

Coaches are building more sessions around one question: how well does a runner hold pace mechanics and oxygen use after an hour or more of work, not just when fresh. (outsideonline.com) In endurance sports, the classic lab markers are maximal oxygen uptake, lactate threshold, and running economy, which is the energy cost of holding a given pace. Outside reported that researchers now treat “fatigue resistance,” also called durability or physiological resilience, as a fourth variable because those first three markers can deteriorate during a race. (outsideonline.com) A 2024 study led by Runar Jakobsen Unhjem compared 10 trained runners with 10 active adults before and after one hour of running at 70 percent of individual maximal oxygen uptake. In both groups, running economy and attainable maximal oxygen uptake got worse after the hour, but the decline was steeper in the less-trained group. (pubmed.ncbi.nlm.nih.gov) A second study, published in 2025 in *Medicine & Science in Sports & Exercise*, tested 28 well-trained male runners with an average 10-kilometer best of 39:02. Half added maximal-strength and plyometric work twice a week for 10 weeks, while the control group kept normal run training. (repository.lboro.ac.uk) In that trial, runners did a 90-minute run near lactate threshold, with running economy checked every 15 minutes, then an all-out effort lasting about five minutes. Running economy had worsened by 4.7 percent before the strength block, but by 2.1 percent after the 10-week strength program. (outsideonline.com) That helps explain why coaches are prescribing workouts that arrive at speed only after some prior load. The goal is not just a bigger aerobic engine in a fresh test, but a smaller drop-off in form and energy cost late in a 5-kilometer, half marathon, or marathon. (outsideonline.com) Outside’s running site has been publishing concrete versions of those sessions for several years. One example is the “600-meter breakdown” workout: 600, 400, 300, and 200 meters fast with 300-meter jog recoveries, done once every seven to 10 days within 10 weeks of a goal race. (run.outsideonline.com) Another example targets economy more directly: 3 x 1 mile at 5-kilometer effort with 3 minutes easy recovery, inside a run that starts and ends with 2 easy miles. Coach David Roche wrote that the session is meant to build relaxed speed and muscular endurance rather than an all-out finish. (run.outsideonline.com) Running economy itself is not a new idea. A long-running review in *Sports Medicine* defined it as the oxygen or energy demand for a given submaximal running speed, which is why two runners with similar maximal oxygen uptake can race very differently. (pmc.ncbi.nlm.nih.gov) The shift is that coaches are now trying to protect that efficiency after fatigue arrives, not only improve it at the start line. For runners, that turns late-race fade from a pacing problem into a trainable trait. (outsideonline.com)