Hello, welcome back to Training Course One.
This is Lesson Four: Conducting a Fitness Test in Adults After Moderate to Severe Traumatic Brain Injury.
The learning objectives for this lesson are to review different options for fitness testing protocols and how to select the right protocol for your client, to understand the procedure for conducting a treadmill test using an individualized protocol, to understand the procedure for conducting a modified shuttle test protocol, and to consider other modes of fitness testing.
First, it is important to understand some key calculations required for fitness testing. Predicted maximum heart rate is calculated using the equation 220 minus the person’s age. If someone is taking beta blockers, which may be prescribed for behavioral reasons, this equation is adjusted by multiplying the result by 0.85. Resting heart rate, as discussed in Lesson Three, should be taken while the individual is at rest, ideally early in the morning.
Heart rate reserve is calculated by subtracting resting heart rate from predicted maximum heart rate. Exercise intensity reflects the desired percentage of effort. For example, a goal of 60% intensity is expressed as 0.6 in the training equations.
To calculate a person’s target training heart rate, the Karvonen formula, also known as the heart rate reserve method, is used. This involves adding resting heart rate to the product of training intensity and heart rate reserve. Heart rate reserve itself is the predicted maximum heart rate minus resting heart rate.
For example, consider a 30‑year‑old male with a resting heart rate of 90 beats per minute who is training at 60% intensity. His predicted maximum heart rate is 190 beats per minute. Subtracting his resting heart rate gives a heart rate reserve of 100 beats per minute. Applying the formula results in a target training heart rate of 150 beats per minute.
When considering which fitness testing protocol is most appropriate for individuals with moderate to severe TBI, it is helpful to review the research literature. Studies have used a variety of test modes and protocols, differing in stage length and the percentage of maximum heart rate achieved.
Cycle ergometer testing generally does not elicit very high percentages of predicted maximum heart rate, particularly when stage lengths are long. Shorter, one‑minute stages are more effective at achieving near‑peak effort. Longer stages may lead to peripheral fatigue before true peak exertion is reached.
Treadmill testing tends to achieve higher percentages of predicted maximum heart rate because it engages larger muscle groups. One‑minute stage protocols on treadmills often enable participants to reach close to their predicted maximum heart rate. Similar results are seen with mechanical stairs, modified shuttle tests, and other field‑based tests that use short stages and large muscle mass.
The key message is that protocols should involve as much muscle mass as possible and avoid long stages that cause fatigue before peak effort can be achieved.
Two fitness testing protocols have been specifically tested and validated in populations with moderate to severe TBI. The first is an individualized treadmill protocol originally developed by Foster and later validated in stroke and TBI populations. In this approach, the therapist selects a walking speed tailored to the individual, aiming for the participant to reach peak effort within eight to twelve minutes.
A familiarization session is typically conducted first, during which the individual walks on the treadmill while the incline is gradually increased. The therapist identifies a speed that feels challenging but manageable at higher inclines, and this becomes the therapist‑selected speed for testing.
During the test, a harness may be used for safety or for body‑weight support, up to 30% if required. The test begins with a one‑minute warm‑up at 70% of the selected speed. In the following minute, the individual transitions to the selected speed, and the incline is increased every minute until peak effort is reached. Inclines typically increase in small increments, potentially reaching up to 15%.
Throughout the test, heart rate, speed, incline, handrail use, and walking or jogging status are recorded each minute. Blood pressure is measured before and after the test, and during the test if feasible. Speed adjustments can be made during the test if heart rate is not rising sufficiently.
The goal is to complete a peak effort test within eight to twelve minutes, or to stop at a pre‑determined submaximal heart rate if appropriate. Safety is a critical consideration, particularly for individuals with lower limb weakness, and the use of a harness may help reduce fall risk.
A standardized recording sheet is used to document all variables. In the example shown, heart rate increased progressively with workload, and the test ended when the participant reported maximal effort with leg fatigue and heavy breathing.
The second validated protocol is the modified shuttle test. This is an adaptation of the standard shuttle test, developed specifically for individuals with TBI and validated for reliability in severe TBI populations. It has also been used in pediatric TBI.
Audio files for the modified shuttle test are available and include standardized instructions for the participant. The test begins at a very slow speed of 2.4 km/h, allowing participants to learn the timing and pacing before speeds increase. Participants walk back and forth along a 20‑metre track, with markers placed at 0, 10, and 20 metres, and sufficient space provided at each end.
Speed increases every minute by 0.8 km/h for the first eight levels. From level nine onward, the test transitions into the standard shuttle protocol, with speed increases of 0.5 km/h per level. This is an externally paced test, requiring participants to keep up with auditory cues.
The test ends when the participant reaches peak effort, achieves a predefined submaximal heart rate, or misses three shuttles in a row. Heart rate is recorded at the end of each level, and blood pressure is measured before and after the test. Safety considerations include the quick turns required, which may increase fall risk for some individuals.
A recording sheet is used to track completed shuttles, missed shuttles, heart rate, and termination criteria. In the example provided, the test was stopped when the participant reached their predicted maximum heart rate, even though their perceived exertion rating remained moderate.
Cycle ergometer testing has not been formally validated in TBI populations, but modified protocols may still be appropriate in some cases. Shorter stage durations, lower starting workloads, and external pacing such as a metronome may reduce peripheral fatigue. A recumbent cycle ergometer and toe clips can improve safety and performance. Electronic ergometers are preferred to ensure consistent workloads regardless of pedal speed.
Other testing options include wheelchair‑based treadmill tests, arm ergometer tests, shuttle tests designed for pulmonary populations, and functional tasks performed with heart rate monitoring. A six‑minute walk test generally does not elicit near‑maximal heart rates in younger individuals with TBI and is better suited to measuring walking endurance rather than cardiorespiratory fitness.
Even individuals in post‑traumatic amnesia may benefit from heart rate monitoring during functional activities to gain preliminary insight into fitness levels.
This concludes Lesson Four. Please complete the accompanying quiz.
Dawes H, Bateman A, Culpan J, et al. The effect of increasing effort on movement economy during incremental cycling exercise in individuals early after acquired brain injury. Clin Rehabil. 2003;17(5):528-34. https://doi.org/10.1191/0269215503cr646oa.
Eerden S, Dekker R, Hettinga FJ. Maximal and submaximal aerobic tests for wheelchair-dependent persons with spinal cord injury: a systematic review to summarize and identify useful applications for clinical rehabilitation. Disabil Rehabil. 2018;40(5):497-521. https://doi.org/10.1080/09638288.2017.1287623.
Foster C, Crowe A, Daines E, et al. Predicting functional capacity during treadmill testing independent of exercise protocol. Med Sci Sports Exerc. 1996;28(6):752-56. https://doi.org/10.1097/00005768-199606000-00014.
Hassett LM, Harmer AR, Moseley AM, Mackey MG. Validity of the modified 20-metre shuttle test: assessment of cardiorespiratory fitness in people who have sustained a traumatic brain injury. Brain Inj. 2007;21(10):1069-77. https://doi.org/10.1080/02699050701630375.
Hunter M, Tomberlin J, Kirkikis C, Kuna ST. Progressive exercise testing in closed head-injured subjects: comparison of exercise apparatus in assessment of a physical conditioning program. Phys Ther. 1990;70(6):363-71. https://doi.org/10.1093/ptj/70.6.363.
Johnston TE, Smith BT, Betz RR, Lauer RT. Exercise testing using upper extremity ergometry in pediatric spinal cord injury. Pediatr Phys Ther. 2008;20(2):146-51. https://doi.org/10.1097/PEP.0b013e318171faa1.
Laskin JJ. Physiological adaptations to concurrent muscular strength and aerobic endurance training in functionally active adults with a physical disability. University of Alberta, 2001. https://www.nlc-bnc.ca/obj/s4/f2/dsk3/ftp04/NQ60316.pdf.
MacKay-Lyons M, Makrides L, Speth S. Effect of 15% body weight support on exercise capacity of adults without impairments. Phys Ther. 2001;81(11):1790-800. https://doi.org/10.1093/ptj/81.11.1790.
Mackay-Lyons MJ, Makrides L. Exercise capacity early after stroke. Arch Phys Med Rehabil. 2002;83(12):1697-702. https://doi.org/10.1053/apmr.2002.36395.
Ozemek C, Bonikowske A, Christle J, Gallo P. ACSM’s Guidelines for Exercise Testing and Prescription (12th Edition). Baltimore: Walters Kluwer, 2025. ISBN: 978-1-9752-1920-8.
Rossi C, Sullivan SJ. Motor fitness in children and adolescents with traumatic brain injury. Arch Phys Med Rehabil. 1996;77(10):1062-65. https://doi.org/10.1016/s0003-9993(96)90069-6.
Tobimatsu Y, Nakamura R, Kusano S, Iwasaki Y. Cardiorespiratory endurance in people with cerebral palsy measured using an arm ergometer. Arch Phys Med Rehabil. 1998;79(8):991-93. https://doi.org/10.1016/s0003-9993(98)90099-5.
Vitale AE, Jankowski LW, Sullivan SJ. Reliability for a walk/run test to estimate aerobic capacity in a brain-injured population. Brain Inj. 1997;11(1):67-76. https://doi.org/10.1080/026990597123827.