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Brain Endurance Training: Does It Work?

Writer: Megan Elliott
Megan Elliott
2 hours ago
11 min read

Brain endurance training is the practice of doing a mentally draining task, such as 20 to 30 minutes of a Stroop test, before, during or after a physical workout, so that the body learns to perform while the mind is tired. Does it work? A 2026 meta-analysis of 11 randomized studies says yes, with a pattern worth knowing: the effect was modest when people were fresh and large when they were mentally fatigued first. This article covers how the method started, what the pooled numbers show, where it fell flat, why the mechanism seems to be effort rather than muscle, and where a citicoline supplement sits in a week that asks a lot of your attention.



Bar chart: brain endurance training's pooled effect on endurance versus physical training alone, SMD 0.21 when tested fresh and 0.87 when tested mentally fatigued (Yu et al. 2026)
Brain endurance training in the 2026 Yu meta-analysis: the pooled endurance effect versus physical training alone was SMD 0.21 when participants were fresh and SMD 0.87 when they were mentally fatigued first.

What brain endurance training is


The idea comes from the mental-fatigue research we covered in our article on mental fatigue and physical performance: after 90 minutes of hard thinking, people quit a cycling test about 15 percent sooner, not because their legs or lungs changed but because the same work felt harder. Brain endurance training, usually shortened to BET, turns that finding around. If mental fatigue makes effort feel heavier, perhaps you can train your tolerance for it the way you train anything else, by exposing yourself to it on purpose, repeatedly, in doses.


The 2026 review in Frontiers in Physiology by Yu and colleagues dates the method to Marcora's group in 2015 and describes it as "dual cognitive and physical loads designed to build mental fatigue resilience." In practice the cognitive load is a computer task that is boring and demanding at once: the Stroop test, where the word RED appears in blue ink and you must name the ink; the 2-back, where you watch a stream of letters and press a key whenever one matches the letter two steps earlier; or a response-inhibition task that punishes a reflexive press. The physical load is whatever the athlete would have done anyway. What varies is the order. Across the 11 studies the review pooled, two put the mental task before training, two after, one ran both at the same time, and five mixed cognitive blocks in between the physical drills. In ten of the 11, the control group did the identical physical training and skipped the mental part.


The handgrip study that showed the mechanism


The cleanest early test came from Dallaway and colleagues, published in the Journal of Science and Medicine in Sport in 2021. Thirty-six people trained their grip for six weeks, 24 sessions of submaximal hand contractions. Half also did a 2-back or Stroop task during every session. Before and after, everyone squeezed a handgrip as hard as they could once a second for five minutes under three conditions: alone, straight after ten minutes of a 2-back task, and while doing one.


Endurance across the three tests improved 32 percent in the BET group and 12 percent in the controls. The physiology is the interesting part. Near-infrared sensors over the forehead showed the BET group holding a higher prefrontal oxygenation during the post-training tests, which the authors read as "suggestive of reduced mental effort during physical activity." The muscle had not learned anything the control group's muscle had not; the brain was spending less to drive it.


What 11 trials add up to


Yu's team searched three databases, screened 11,046 records and kept nine papers reporting 11 randomized studies, 438 participants in all, 177 trained with BET and 261 as controls. Interventions ran four to twelve weeks at two to five sessions a week. The participants were healthy: footballers, cyclists, racket-sport and gymnastics athletes, a laboratory group, and in one trial sedentary older women.


Outcome (BET versus physical training alone)

Pooled effect

Reading

Endurance, tested fresh

SMD 0.21 (95% CI 0.08 to 0.34)

Modest but significant

Endurance, tested after a fatiguing mental task

SMD 0.87 (0.61 to 1.13)

Large; the headline result

Stroop reaction time, fresh

56.6 ms faster (16.5 to 96.7)

Three studies

Vigilance reaction time, fatigued

18.7 ms faster (15.3 to 22.2)

Consistent across studies

Self-rated mental fatigue, fatigued state

9.2 points lower (1.6 to 16.8)

High heterogeneity (I² 96%)

Self-rated mental fatigue, fresh

No difference

BET does not make a rested person feel fresher


SMD is a standardized mean difference, where 0.2 is conventionally read as a modest effect, 0.5 as medium and 0.8 as large. Read the table top to bottom and the story is consistent: BET matters most at the moment mental fatigue would otherwise cost you. When participants were tested rested, the BET groups edged ahead. When they were tested after 30 minutes of a Stroop task, the gap opened wide, in endurance, in reaction time and in how tired they said they felt.


The review's own cautions deserve equal billing. None of the 11 studies could blind participants to which group they were in, so every one was rated high risk for performance bias; expectation may be doing some of the work. Egger's test flagged possible publication bias for the endurance outcomes. Sensitivity analyses "showed that excluding certain studies led to noticeable changes in the effect estimates, and in some cases shifted results from significant to non-significant." Eleven studies is a start, not a settled field.


Where it worked, and where it did not


The individual trials show what the pooled numbers hide. In a preseason camp described in the International Journal of Sports Physiology and Performance in 2022, 22 professional footballers did 40 physical sessions in four weeks; the players who finished each day with cognitive training were afterward faster on an intermittent fitness test, a repeated-sprint test and a reactive-agility test, made fewer agility errors, and answered the Stroop faster than the control players, who listened to neutral sounds instead.


Road cyclists told a more textured story in the same group's 2023 paper in the Journal of Science and Medicine in Sport. After six weeks of response-inhibition tasks following every ride, time to exhaustion improved more than in controls at both 80 and 65 percent of peak power, and a 20-minute time trial improved more too, both with lower ratings of effort. A five-minute all-out time trial did not budge. "No group differences were found in physiological measures": heart rate and lactate were the same, which is exactly what the handgrip study predicted. BET changes the long, grinding effort, not the short, maximal one.


A 2025 study of 31 professional soccer players, also in the Journal of Science and Medicine in Sport, sharpened the point. Passing, shooting and vigilance improved after six weeks of intermixed BET, but only when the players were tested after a 30-minute Stroop task, not when they were fresh. And in a 2026 study in Sports, 13 Danish national-team orienteers who added 20 minutes of route-choice practice after each weekly aerobic session got 27 percent faster at choosing routes, but "running performance did not differ significantly between periods." Train the brain on maps and you get better at maps. The legs are a separate account.


The method also reaches past sport. In a 2025 trial in Psychology of Sport and Exercise, 24 sedentary women aged 65 to 78 were split three ways: eight weeks of exercise, the same exercise preceded by a 20-minute cognitive task, or no training. Both training groups beat the controls, and the BET group beat the exercise-only group when tested fatigued, with cognitive performance up 7.8 percent versus 4.5, and physical performance up 29.9 percent versus 22.4.


Why it works: effort, not muscle


Put the findings side by side and the mechanism is hard to miss. Heart rate, lactate and oxygen uptake do not differ between BET and control groups. Ratings of perceived exertion do, and so does prefrontal oxygenation. The training does not build a different engine; it changes how expensive it feels to run the one you have while part of your attention is occupied. That matches the mental-fatigue research, where the cost of a hard hour of thinking was always perceptual, and it explains the fresh-versus-fatigued split in the table: a rested person has little mental fatigue to be resistant to, so the training has nothing to show until the fatigue arrives.


That also sets the limits. BET is training for a specific situation, performing under a cognitive load, and the studies that measured a short maximal effort found no change in it.


What this means if you are not a professional


The honest translation starts with who was studied: footballers, cyclists, orienteers, a lab group and one trial of older women, in programs of four to twelve weeks, two to five sessions a week. Nobody has tested a 6 PM gym session after a day of spreadsheets, so the findings are a direction, not a prescription. Within that limit, three things are reasonably supported.


First, the dose that worked was substantial. The review's exploratory comparisons leaned toward programs of eight weeks or longer and fewer than four sessions a week, and toward doing the mental task before the physical one, but it states plainly that none of those subgroup differences reached significance and that they "should be interpreted with caution." Second, the mental task was demanding, standardized and timed, 20 to 30 minutes of something you would rather not do, which is a different thing from scrolling your phone between sets. Third, the benefit showed up in sustained efforts and in judgment under fatigue, not in a single sprint or lift.


If your afternoons fade for reasons that have nothing to do with training, that is the body clock and lunch, which we cover in our article on the afternoon slump. Brain endurance training is for the other case: you know the demanding thinking is coming, and you want the hour after it to cost less.


Where Great Billiom Citicoline fits


Great Billiom Citicoline CDP Choline, 1,000 mg per two-capsule serving — supports memory, focus and mental clarity with clean mental energy
Great Billiom Citicoline CDP Choline, 1,000 mg per two-capsule serving, on a desk beside a laptop and a pair of running shoes — supports attention and follow-through on demanding work, with clean mental energy and no caffeine or sugar.*

Brain endurance training works by making the brain pay a cost on purpose, in training, so that the same cost is more bearable later. A citicoline supplement enters from the supply side of that account. Citicoline is cytidine diphosphate-choline, a compound the body splits into cytidine and choline; choline is what the brain uses to make acetylcholine, the messenger tied to attention, and both pieces go into the membranes of brain cells. Our guide to supplements for memory and focus walks through what the randomized citicoline trials in healthy adults measured, attention and memory tasks over four to twelve weeks, and where the choline on a plate comes from.


What those trials did not measure is this article's subject. No citicoline study has put participants through a Stroop task and then a time trial, so this article makes no claim about citicoline and brain endurance training. What we can say is what the product is for. Great Billiom Citicoline CDP Choline provides 500 mg of citicoline per capsule and 1,000 mg per two-capsule serving, and the product page describes it as made for professionals, students and active minds: support for attention and follow-through on demanding work, from long deep-work blocks to exam prep, with clean mental energy and no caffeine or sugar. The directions are two capsules once a day with food, ideally in the morning. A bottle holds 90 capsules, a 45-day supply. Anyone taking prescription medication, pregnant or nursing, or managing a medical condition should talk to their doctor before adding it.



Key takeaways


  • Brain endurance training pairs a demanding mental task (Stroop, 2-back, response inhibition) with physical training to build tolerance for mental fatigue; the method dates to 2015 (Yu 2026).

  • Across 11 randomized studies and 438 participants, BET improved endurance over physical training alone, modestly when people were fresh (SMD 0.21) and strongly when they were mentally fatigued first (SMD 0.87); vigilance and Stroop reaction times improved too (Yu 2026).

  • The gains come without changes in heart rate, lactate or oxygen uptake and with lower perceived effort and higher prefrontal oxygenation, so the training changes the cost of effort, not the engine (Dallaway 2021; Staiano 2023).

  • It did not move everything: a five-minute all-out time trial in cyclists and running performance in orienteers were unchanged, and soccer skills improved only when the players were tested fatigued (Staiano 2023; Buch 2026; Staiano 2025).

  • No study was double-blind, publication bias was flagged for the endurance outcomes, and the review calls its dose findings exploratory; the field is promising and still young.


The research gives you one clear move: if a hard effort tends to follow a hard hour of thinking, rehearse that order in training rather than avoiding it, and expect the payoff when you are tired, not when you are fresh. For the thinking hours themselves, Great Billiom Citicoline CDP Choline gives you 1,000 mg of citicoline per two-capsule serving as a daily choline source that supports focus and mental clarity without caffeine or sugar.



Frequently asked questions


What is brain endurance training?


Brain endurance training (BET) adds a mentally fatiguing cognitive task, typically 20 to 30 minutes of a Stroop, 2-back or response-inhibition test, before, during or after physical training, to build tolerance for mental fatigue so performance holds up when the mind is tired. Marcora's group introduced the method in 2015, and 11 randomized studies had tested it by 2026.


Does brain endurance training actually work?


In the 2026 meta-analysis of 11 randomized studies, yes: endurance improved more with BET than with physical training alone, modestly in rested participants (SMD 0.21) and strongly after a fatiguing mental task (SMD 0.87), with faster reaction times as well. The caveats are real: no study was double-blind, and the review flagged possible publication bias for the endurance results.


How long does brain endurance training take to show results?


The programs in the research ran four to twelve weeks at two to five sessions a week, and the shortest, a four-week preseason camp in professional footballers, already showed differences. The review's exploratory comparison favored programs of eight weeks or longer, but that difference was not statistically significant, so treat it as a lead rather than a rule.


Why does brain endurance training help more when you are tired?


Because the training targets mental fatigue itself. Rested participants have little fatigue to be resistant to, so the benefit is modest; after 30 minutes of a Stroop task, the trained groups kept more of their endurance, reaction speed and technical skill than controls. Physiological measures such as heart rate and lactate did not differ, while perceived effort was lower.


Does a citicoline supplement improve brain endurance training?


No citicoline trial has tested it, so we make no claim about citicoline and brain endurance training; the randomized trials in healthy adults measured attention and memory over four to twelve weeks. Great Billiom Citicoline CDP Choline is a daily choline source, 1,000 mg per two-capsule serving, that supports memory, focus and mental clarity without caffeine or sugar.


Megan Elliott, Content Editor at Great Billiom. Every claim in this article is sourced from the primary research linked above. Read our editorial standards → thegreatbilliom.com/editorial-standards


Sources



These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.


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