After seeing a boom in interest near the start of the 21st century, the international sport of roller derby has been growing at a steady pace. In order for skaters to play at their peak performance, they need to adapt to the ways atmospheric conditions such as temperature and humidity affect their rinks and their bodies.
"Temperature and humidity affect the stickiness of the floor, which directly correlates to how fast you can skate, how much you can slide, certain moves you can do," said Susan "Suenami" Varner, captain of the Happy Valley Dolls, the A-level travel team for the State College Area Roller Derby league.
Having evolved from the dramatized version of the game that was popular in the 1970s, modern flat-track roller derby is a hard-hitting contact sport played on quad-style roller skates. Varner explained that depending on the conditions, skaters will switch the wheels on their skates to maximize how they perform on the track.
Rachel "Blackout Betty" Gaddis, president of State College Area Roller (SCAR) Derby and a member of the Happy Valley Dolls, said that it is the wheels' hardness, called the durometer, that makes the biggest impact on different floor surfaces.
"This rink, in the summer, gets very humid inside," Gaddis said. "We actually get a lot of condensation on the floor. With our floor being so sticky and humid, you want your harder wheels so you actually still have a slide, but also still have the grip with the floor and your wheel."
At the most basic level, flat-track derby is played by two teams on an oblong track. Each team fields a jammer, who scores points for each opponent she skates past. The blockers on the track work simultaneously to stop the opposing jammer from getting past them, and they assist their own jammer who is working to get through the pack.
Currently, more than 1,300 women's leagues, men's leagues, junior derby, flat-tracked and banked-track leagues are registered across the globe.
"Roller derby has come a long way from the smash mouth, big hits, staged production of yesteryear," said Chris Brace, head coach of the Happy Valley Dolls. "It involves strategy, gameplay, sportsmanship and constant training and practice."
The high intensity of the game can take a physical toll on skaters. Hydration is an essential step for players to avoid health complications.
"After you get 28 girls out there, pushing their bodies to the edge, and crowds that can be well into the hundreds, the temperature and humidity will quickly become unbearable, especially in the summer months," Brace said.
The gear skaters are required to wear--helmets, knee pads, elbow pads and wrist guards--can make it harder for the body to cool down, Brace said. Skaters need to drink water constantly, not just when they feel thirsty.
"If you wait till you're thirsty to drink, you're already about two cups of water short," he said. "It's important to drink before, during and after games. If you're getting goosebumps and chills, it's too late. You're dehydrated. If I know one of my players is dehydrated, I will have them sit out and get the EMTs to look them over."