Balancing exercise risk and benefits: lessons learned from sickle cell trait and sickle cell anemia

Abstract

Development of exercise guidelines for individuals with sickle cell trait (SCT) and sickle cell anemia (SCA) is hampered by the need to weigh the benefits against risks of exercise in these populations. In SCT, concern for exercise collapse associated with sickle cell trait has resulted in controversial screening of student athletes for SCT. In SCA, there exists unsubstantiated concerns that high-intensity exercise may result in pain and other complications. In both, finding the "right dose" of exercise remains a challenge for patients and their providers. Despite assumptions that factors predisposing to adverse events from high-intensity exercise overlap in SCT and SCA, the issues that frame our understanding of exercise-related harms in both are distinct. This review will compare issues that affect the risk-benefit balance of exercise in SCT and SCA through these key questions: (1) What is the evidence that high-intensity exercise is associated with harm? (2) What are the pathophysiologic mechanisms that could predispose to harm? (3) What are the preventive strategies that may reduce risk? and (4) Why do we need to consider the benefits of exercise in this debate? Addressing these knowledge gaps is essential for developing an evidence-based exercise prescription for these patient populations.

Conflict of interest statement

Conflict-of-interest disclosure: The author declares no competing financial interests.

© 2018 by The American Society of Hematology. All rights reserved.

Figures

Figure 1.

Timeline of important milestones related to application of exercise science and medicine in SCT and SCA. 6-MWD, 6-minute walk distance; ACSM, American College of Sports Medicine; CHAMP, Consortium for Health and Military Performance; NATA, National Athletic Trainers’ Association; NCAA, National Collegiate Athletic Association.

Figure 2.

The balance of short-term potential risks of acute exercise vs long-term benefits of regular exercise in individuals with SCT and SCA.