Helping Soldiers Train Their Brains and Bodies to Improve Endurance

By Paul Lagasse, USAMRDC Public Affairs OfficeOctober 20, 2023

Helping Soldiers Train Their Brains and Bodies to Improve Endurance
1 / 4 Show Caption + Hide Caption – Service members completing a 45-minute physical training session while also performing a concurrent cognitive task on a tablet placed in front of the treadmill screen. (Photo Credit: Paul Lagasse) VIEW ORIGINAL
Helping Soldiers Train Their Brains and Bodies to Improve Endurance
2 / 4 Show Caption + Hide Caption – A study participant conducts a novel dynamic marksmanship test in the Engagement Skills Trainer-II simulator. (Photo Credit: Paul Lagasse) VIEW ORIGINAL
Helping Soldiers Train Their Brains and Bodies to Improve Endurance
3 / 4 Show Caption + Hide Caption – A study participant completes an active cooldown following their baseline endurance test. (Photo Credit: Paul Lagasse) VIEW ORIGINAL
Helping Soldiers Train Their Brains and Bodies to Improve Endurance
4 / 4 Show Caption + Hide Caption – Dr. Brad Fawver supervises a Soldier completing their baseline endurance test, which includes measuring their maximum heart rate, oxygen consumption and perceived exertion. (Photo Credit: Paul Lagasse) VIEW ORIGINAL

Soldiers have long known that a disciplined regimen of physical exercise can improve their physical strength. Researchers at the U.S. Army Medical Research and Development Command’s Walter Reed Army Institute of Research are now exploring ways to augment physical exercise with “brain exercise” that could potentially help Service Members enhance their performance under stress and fatigue conditions.

“We’re not saying that cognitive training can make you smarter,” says Dr. Brad Fawver, a research scientist at WRAIR’s U.S. Army Medical Research Directorate-West. “But it’s well established that we tend to get better on the things we train on and get worse on things that we ignore.”

Building on the pioneering work of USAMRD-W Director Lt. Col. Michael Dretsch, Ph.D., Fawver is spearheading the Brain-Physical Optimization Conditioning research program. With funding support from USAMRDC’s Military Operational Medicine Research Program, B-POC evaluates novel strategies to build the resilience of Service Members through mind-body training and other integrated interventions. One approach the team is testing utilizes brain endurance training, or BET, which involves performing mentally demanding tasks (say, recalling a particular sequence or array of shapes, symbols and colors) either before, during or after strenuous physical exercise. It’s this inclusion of mental fatigue alongside physical fatigue that Fawver and other researchers believe alters the brain’s tolerance of exhaustion.

This is important because published reports show how muscle and joint fatigue is preceded by brain-derived perceptions of exertion that dictate how long a person is willing to push themselves before shutting down – often prematurely. Mental fatigue also negatively impacts a wide range of physical and technical skills including exercise, sports, driving and flying. Research has shown that people who incorporate BET into their aerobic training experience improved physical performance outcomes and also that BET appears to induce functional alterations in the parts of the brain associated with perceptions of demand, effort and fatigue.

Fawver provided a review of the B-POC program’s recent accomplishments at the 2023 Military Health System Research Symposium on August 17, 2023. In their first series of tests, a group of volunteer Service Members participated in a six-week training program in which half of the volunteers performed a low- to moderate-demand memory task while running on a treadmill for 45 minutes, while the other half performed a memory task with virtually no demand while doing the same exercise. Each participant was given comprehensive pre- and post-training assessments that included an endurance test, a series of cognitive tests while fatigued and a dynamic marksmanship test both before and after a ruck march.

Fawver’s team found that the volunteers who were given the low- to moderate-demand memory tasks during their training displayed twice the improvement in endurance performance and twice the reduction perceptions of exertion compared to the control group following the six-week training.

“We designed this first study to be fairly simple, as a way to minimize the number of variables while also extending the science,” Fawver explains. “But we were floored by the results. Some very physically fit Soldiers were running 5 to 15 minutes longer on a test that they previously ran to complete failure just six weeks prior. This gives us the confidence to evaluate more complex and challenging training approaches.”

The team at USAMRD-W is currently exploring the utility of this approach with high-intensity interval and circuit training exercise, both of which align better to the current Army Combat Fitness Test. With the help of stakeholders like the Army’s Holistic Health and Fitness Program, the team will be able to identify other potential applications. They are also interested in the benefits of operational training tasks, psychological skills development and even neurostimulation during physical training. One project will stimulate participants’ vagus nerve during exercise rest periods to enhance their cognitive functioning.

Many questions remain about how to optimize these training approaches, including whether any changes last longer than a few weeks.

“I wish I could tell you we had all the answers,” says Fawver, “but we’re starting to narrow down the underlying neural mechanisms and apply that knowledge towards ‘gamifying’ the training system.”

To bolster their research, the USAMRD-W team has developed international partnerships with the Brazilian Army Research Institute of Physical Fitness and The Arctic University of Norway to evaluate this training approach in combination with a range of strenuous physical exercises in extreme climates. Future research and development will also examine individual differences in tolerance and identify other psychological and physiological processes contributing to the effectiveness of BET.

“A lot of folks think of psychological resilience as something extra beyond the physical body, a tool that you have to reach down in your bag and get,” says Fawver. “But the best form of resilience is not resource consuming per se; it's implicit and integrated, and it becomes part of your operational skill set. Training like this will produce Warfighters that are much more resistant to things like anxiety, physical stress and all those other operational demands that get placed on them in deployed environments.”

Ultimately, the USAMRD-W team aims to see these cognitive training tools tailored to an individual’s personal health and fitness goals. The inclusion of performance feedback or other incentives could be included to enhance engagement, such as competition with family, friends, coworkers or leaderboard rankings at their local installation. As Fawver points out, nearly everyone has a wearable, a cell phone or a tablet that they can use to engage in brain exercises during physical exercise.

“This this is where the fun begins, because you’re finally starting to see more studies corroborating the effects of these integrated interventions,” says Fawver. “We’re excited about where this research will take us, but the challenge is to create something truly innovative and impactful for Service Members’ brain health and performance. They’ll always be our chief focus.”