Sickle cell trait (SCT) is an inherited disorder from just one parent where hemoglobin’s ability to carry oxygen in your bloodstream is reduced. Hemoglobin is a protein found in red blood cells that carries oxygen to various tissues in the body, including muscles. Worth noting, SCT is different than sickle cell disease (SCD). SCD is inherited from both parents, causing the red blood cells to be shaped differently, significantly impairing the ability of oxygen to be shuttled around the body. It has been estimated that between 1 and 3 million Americans have SCT, and of those affected, 8-10% are African American.
What are the symptoms?
Actually, symptoms from SCT are relatively rare. When symptoms do arise, however, one common symptom is pain or discomfort when exercising at high altitudes. Another one is an intermittent pain when exercising, especially in warmer, humid weather. Because of SCT, those with the trait are more likely than other players who experience muscle breakdown or experience heat exhaustion, or in extreme cases, heat stroke.
How does it affect the body?
As stated above, hemoglobin is a protein in red blood cells that helps to carry oxygen to your working tissues in the body, including muscles. Whenever this complex mechanism is impaired, muscles are unable to perform at their peak capacity. Through metabolism (the breakdown of energy), muscles rely on oxygen in order to be able to repeatedly contract and relax. Essentially, this is how we move – everything from walking to running to lifting weights to playing football. Because of the trait, NFL players are more likely than their competitors to experience muscle cramping, spasm, fatigue, and even muscle strains or damage. In extreme cases, SCT can even cause death. According to a study from the University of Washington, college football players with SCT were 37 times more likely than athletes without the trait to experience exercise-related sudden death.
What do NFL players who have SCT have to say about their symptoms?
“It’s like a regular tired feeling. For someone who doesn’t have it, if they are running 20 ‘110s’ [sprints], they are dying on the 18th one. If you have a flare-up, you might feel it on the eighth or ninth sprint.” – Jerraud Powers, former Arizona Cardinals defensive back
“There’s constant cramping.” – Devard Darling, former Baltimore Ravens receiver
“I called my wife and told her I didn’t think I was going to make it. I’d never been in that much pain.” (in reference to spleen damage after playing in Denver) – Ryan Clark, former Pittsburgh Steelers defensive back
“It does make me scared a little bit, a little nervous because I’m risking my life.” (in an interview discussing whether he would play in Denver in 2016) – Tevin Coleman, Atlanta Falcons running back
“There wasn’t a hit that I took. We think it’s related to the sickle-cell trait.” (in reference to blood spotted in his urine) – Ty Montgomery, Green Bay Packers running back
Does SCT keep NFL players off the field?
To answer this question, let’s take a look at how three notable players with SCT have performed over the years – Tevin Coleman, Ty Montgomery, and John Brown. In addition, we’ll dive into their performance when playing at the high altitude in Denver.
Tevin Coleman – Coleman suffered a hamstring strain in 2015 during training camp but didn’t miss any time once the regular season began. However, in 2016 he missed 3 games due to another hamstring injury. He has only played in one career game at Sports Authority Field in Denver, but when he did, he played very well. He carried the rock 6 times for 31 yards and also reeled in 4 receptions for 132 yards and a score. His 26.3 PPR fantasy points that day helped Atlanta beat Denver 23-16.
Ty Montgomery – ‘Ty Mo’ has only missed one career game due to SCT. In 2016, he missed one game due to blood that was found in his urine. Reportedly, he didn’t suffer any direct trauma, but doctors suspect that the kidney dysfunction was related to his sickle cell trait. See the quote above. Montgomery only played against the Broncos in Denver once, and it was during the pre-season in 2017. It’s tough to read into it much, but he rushed the ball 3 times for 31 yards and a score.
John Brown – Brown has probably been affected by SCT the most out of this group of guys. He first missed one week due to hamstring cramps in 2015. In 2016, he also missed just one game during the season but struggled throughout the year, as he was frequently listed on the Cardinals injury report and played fewer snaps. Last year, Brown strained his quadriceps during training camp, which caused him to miss 3 pre-season games and 2 regular season games. He has played just one game in Denver and was a non-factor. He caught 2 balls for 4 yards.
Players with SCT can suffer from a variety of symptoms, including muscle strains, cramps, and kidney damage. In addition, when playing in high altitude where the oxygen levels are lower, these players are more likely to experience fatigue more quickly than others. Injuries are related to the fact that the player’s blood cells have a reduced capacity to carry oxygen to working tissues in the body.
It’s difficult to predict injury with these players, so from a fantasy football perspective, owners should only consider whether or not a player has SCT as a secondary factor when drafting. Due to the difficulty in predicting injury in this group, I would argue that owners look at past SCT-related injuries when factoring the risk associated with owning these players in fantasy. For example, John Brown probably carries more risk than Tevin Coleman.