Jen Schumacher, the third swimmer of the unprecedented 88-mile (141.6K) Ultimate Swim Relay, conducted an interesting research project on herself, together with Dr. Daniel Judelson and Dr. Lenny Wiersma, as she swam across the Catalina Channel in 2009 in 9 hours and 2 minutes. Their findings were reported at this year’s American College of Sports Medicine annual meeting.
Jen attached a telemetric monitor that recorded her heart rate at five-second intervals. Every 24 minutes, she rested and hydrated for 60 seconds during which time she reported perceived pain on a scale of 0-10, her rate of perceived exertion on a scale of 6-20, perceived thermal sensation on a scale of 0-8 and perceived thirst on a scale of 1-9. Her collaborators tracked the air and water temperatures and average velocity at these same intervals using a GPS device.
Jen found her heart rate (148-155 beats per minute) and thermal sensation (3-4) remained consistent across the 21-mile channel that averaged 19.1°C (66.4°F). Her pain varied inconsistently from 0-5 during the swim while her rate of perceived exertion remained between 12-14 for the first eight hours in the channel, but it increased dramatically in the 40 minutes, ultimately reaching 18 by the time she walked up the California mainland. Her thirst sensation steadily increased throughout the swim, similarly reaching maximum values at the end of her swim.
The thousands of channel swimmers who have attempted and succeeded swims in the Irish Channel, Cook Strait, Molokai Channel, English Channel, Catalina Channel, Tsugaru Channel, Strait of Gibraltar and other channels around the world can greatly appreciate this team’s concrete findings.
Jen, Dr. Judelson and Dr. Wiersma believe that future efforts to understand the physiological and perceptual responses during marathon swimmers can aid in the preparation and performance of future swimmers.
We look forward to this future research.
Photos above show Jen before and after her Catalina Channel crossing of 9:02.
Copyright © 2010 by Steven Munatones