Among activity types, moderate exercise provides best ALS protection

Lifetime physical activity did not appear to increase risk for ALS, whereas occupational physical activity seemed to be a risk factor for the disease, according to study results published in Neurology.

“We wanted to be able to advise ALS patients in their ability to influence their outcome (survival) in the form of optimal exercise and to gain insight in exercise-related ALS risk and prognosis,” Angela Rosenbohm, MD, of the department of neurology at Ulm University in Germany, told Healio Neurology. “We are searching for the early disease symptoms, which may be of high relevance for future therapies.”

Because few studies have reported data on life-long physical activity, it remains unclear whether physical activity plays a role in ALS. To address this research gap, Rosenbohm and colleagues aimed to analyze data on cumulative, leisure time and occupational physical activity, as well as gather evidence on the capacity of physical activity, to predict disease course.

Researchers collected lifetime physical activity values via questionnaires that addressed work and leisure time. They quantified these data into metabolic equivalents. To calculate ORs of ALS by physical activity in various time internals and prognosis, they used a population-based case-control study embedded in the ALS Registry Swabia (393 patients with ALS; 791 age- and sex-matched controls).

Results showed a reduction in total physical activity at interview and up to 5 years prior to interview among patients with ALS compared with controls. Rosenbohm and colleagues observed no association between total physical activity and ALS risk between 5 and 55 years prior to interview. However, they did report an association between heavy occupational work intensity and increased ALS risk (OR = 1.97;95% CI, 1.34-2.89). Total physical activity levels correlated with survival in a nonlinear manner, with inactive patients and highest activity levels linked to the worst survival times of 15.4 months and 19.3 months, respectively. After adjusting for other prognostic factors, the best median survival (29.8 months) correlated with 10.5 metabolic equivalent hours per week.

“The best prognosis after being diagnosed with ALS was seen in moderate exercise (cycling about 2 to 3 hours per week), almost doubling the survival compared with little moving and overactive patients,” Rosenbohm said. “The same could be seen for exercise in the decades before being diagnosed with ALS, with moderate exercise also beneficial for the later survival. Heavy exercise at work was associated with a double risk for developing ALS, but none of this effect was seen in the same leisure time exercise.”