Graduation Year


Document Type




Degree Granting Department


Major Professor

Lorena Madrigal, Ph.D.

Co-Major Professor

Wendy Nembhard, Ph.D.

Committee Member

Elizabeth Miller, Ph.D.


athlete, exercise, exertional, fetal hemoglobin, military



Introduction Sickle cell trait carriers may experience sickling events, which can cause severe health problems. Some sickle cell haplotypes contain genetic modifiers that are associated with increased levels of fetal hemoglobin, which is resistant to sickling. The aim of this study is to determine if sickle cell trait individuals who do not carry these modifiers are more likely to experience sickling episodes than those who do carry the modifiers.

Methods: Participants were eligible for inclusion in this study if they were male, 18 years of age or older, a sickle cell trait carrier, and had previously played any level of organized football. Participants were recruited via Facebook,, e-mail, phone calls, and word of mouth. They were asked to complete a survey and return a buccal swab for genetic analysis to look for alleles associated with fetal hemoglobin persistence. To date, no genetic analyses have been run. Data from the surveys was analyzed using Fisher's Exact Test with the SAS 9.2 software.

Results: Twenty participants were included in this phase of the study and all returned both the survey and buccal swab. Five of the 20 participants had been diagnosed with exertional sickling, 2 with heat illness, and 12 had experienced dehydration.

Conclusion: Data in this study is purely observational, as no genetic analyses have been performed at this point. Early results indicate that the probability a player feels their muscle pain lasts longer than their peers' is greater among those who feel it takes their muscles longer to recover than their peers'.