Even national record holders get nervous.
Sydney McLaughlin, who set the indoor all-time standard for the 400m this March in 51.84 -- the first prep to break 52 seconds for a quarter mile indoors -- said she suffers from unbearable nerves; the kind that make you wake up at two or three in the morning and text your coach just to make sure you remember what to do.
"Sydney, she gets nervous," said Union Catholic head coach Mike McCabe. "But she responds well to nerves."
Those nerves helped the 17-year-old win the IAAF World Youth Championship last summer for 400m hurdles, which she will contest at the U.S. Olympic Team Trials in June.
But this weekend, she's focusing on the 4x400m with her Union Catholic teammates at the Penn Relays Carnival.
The Vikings could be the first Americans to win the High School Girls 4x400m Championship of America since 2008, when the Eleanor Roosevelt Raiders from Beltsville, Maryland, took the crown in 3:37.16.
Union Catholic's school record is faster than that. Their 3:35.9 clocking last June won New Balance Nationals Outdoor and barely missed the national record of 3:35.49 set by Long Beach Poly in 2004.
They are also the defending New Balance Nationals Indoor champions. They ran 3:40.28 with their current line-up, which ranks No. 2 all-time indoors.
But will they be enough to contend with the Jamaicans?
Five Jamaican teams enter with seed times at 3:41 or faster: St. Elizabeth Tech (3:36.91), Holmwood Tech (3:37.35), Hydel (3:38.37), St. Jago (3:40.7), and defending champions Edwin Allen (3:41.28).
The Vikings race in Heat No. 144 on Thursday at 4:15 p.m. In recent years, it's taken around 3:50 to advance to the Championship of America final, which will be contested at 4:20 p.m. on Friday.
"I think of (prelims) as a shake-off for the nerves," Union Catholic senior Amari Onque-Shabazz said. "So when that final comes, you have nothing to worry about. You just go out and run."
In Coach McCabe's 13-year tenure, three Union Catholic teams have made Championship of America finals: the boys 4x400m in 2013 and 2014, and the boys 4x800m in 2014.
"It's not an easy year," McCabe said. "The Jamaican teams are loaded. The girls have to be able to step on the track at Penn and not change what we always do. Obviously, the race and the competition are different, but each kid needs to stay within their own focus and stay within the plan. If someone goes out in 24.5 instead of 25 or 26, well, we're probably going to lose two seconds. To me, that's the big piece, being able to handle the moment."
Last year, there wasn't a moment to handle. A few injuries left the Vikings without an "A" squad on the biggest relay stage of the year.
McLaughlin suffered hamstring tightness and spent three hours in the trainer's tent at Franklin Field before McCabe called it a weekend.
Onque-Shabazz raced that day with three alternates.
"Last year, we went into it looking to make the final," she said. "But after the injuries, we just wanted to break four minutes."
The senior is a two-time New Jersey MOC champion in the 800m, but she will trade her usual spot in the Vikings' 4x800m to focus solely on the mile relay. Everyone wants to win the wheel, but perhaps especially Onque-Shabazz, who will compete for Villanova next year.
"Penn Relays is like a home meet to Villanova," she says. "It would mean so much to go home with the wheel and then be going to 'that school that always wins.' It's all about our mindset. Everyone is fit. It's just about who is not fearless."
For McLaughlin, it's about channeling those nerves into fearlessness.
"At first, the crowd at Penn is nerve-wracking," McLaughlin says. "But when the gun goes off, it boosts your energy. It just fuels you."