There is a paucity of research dealing with exercise and Down syndrome. Individuals with Down syndrome have challenges when it comes to exercise; endocrine dysfunction, hyperflexibility, hypotonia, and challenges with motor skill development can make an exercise program challenging with this population. Nevertheless, it is important as individuals with Down syndrome tend to have a lower resting metabolic rate and (as a result) a greater body mass index. The research that has been done on exercise and Down syndrome seems to indicate that it can have beneficial effects to aerobic fitness, muscular strength, and muscular endurance though it is unclear if it has a beneficial effect on BMI.
Two articles were published in December; one by Casabona et al in the Journal of Applied Physiology, one by Pastula et al in the Journal of Strength and Conditioning Research, that have important information for the professional working with individuals with Down syndrome.
Individuals with Down syndrome are hyperflexible (their joints are loose) and experience hypotonia (low muscle tone). This results in their potentially being more susceptible to joint injuries and also means they cannot react quickly to sudden changes in the environment (like a fall). With this in mind, Casabone et al conducted a study looking at how adults with Down syndrome control their leg muscles. The authors had a group of subjects with Down syndrome perform a knee extension pendulum test (the individual is seated, knee extended manually by experimenter, then the lower leg is allowed to drop). They found that the individuals with Down syndrome behaved differently during the test than individuals without. When the lower leg was “released,” the individuals with Down syndrome activated their knee extensors to slow down the unexpected descent of the lower leg – whereas individuals without Down syndrome did not do this. The authors suggest that this might be an adaptations to the hyperflexibility and hypotonia seen in individuals with Down syndrome (i.e. it might be an adaptation to keep the joints stable).
Pastula et al studied the impact of exercise on cognitive and cardiovascular function in individuals with intellectual disabilities including several subjects with Down syndrome. They studied sixteen individuals and had them participate in an exercise program that ran three days/week for eight weeks. The program included total body circuit training that incorporated some dumbbell work with bodyweight training and “aerobic” sports activities. The intent was to have the subjects train at 60-70% of maximum heart rate during the exercise interventions for approximately an hour.
At the end of eight weeks, aerobic fitness increased by almost 18%. In addition, the cognitive measures that were studied improved as well (visual matching, decision speed, and pair cancellation) by 13-48%.
Taken together these studies suggest some interesting things. First, if individuals with Down syndrome have adaptations to keep their joints stable, and these adaptations involve muscular contractions, then strengthening these muscles could only assist. Second, the Pastula et al study reinforces that exercise improves fitness (and thus health/activities of daily life), but it is also valuable to helping with cognitive functioning.
Casabona, A., Valle, M.S., Pisasale, M., Panto, M.R., and Cioni, M. (2012). Functional assessment of the knee joint biomechanics by using pendulum test in adults with Down syndrome. Journal of Applied Physiology, 113: 1747-1755.
Cissik, J.M. (2012). Down syndrome: An introduction for the strength and conditioning professional. Strength and Conditioning Journal, 34(1): 76-81.
Pastula, R.M., Stopka, C.B., Delisle, A.T., and Hass, C.J. (2012). Effect of moderate-intensity exercise training on the cognitive function of young adults with intellectual disabilities. Journal of Strength and Conditioning Research, 26(12): 3441-3448.