Harvard professor runs across America in record-breaking time

By Sanj Atwal
split image of Jenny Hoffman running

Harvard physics professor and three-time national ultrarunning champion Jenny Hoffman has officially broken the record for the fastest crossing of America on foot (female) after running across the entire country in 47 days 12 hr 35 min.

The 45-year-old mother of three started at San Francisco City Hall and finished almost seven weeks later at New York City Hall, beating the previous record by over seven days.

Jenny typically ran for 13-15 hours every day, starting at 4 a.m. She rarely walked, except when going up steep hills.

She consumed up to 8,000 calories per day (mostly in the form of eggs) to ensure her weight remained stable.

Jenny running on winding road

Jenny had previously attempted this record in 2019; she reached Ohio after 42 days when her knee gave out, ending the run. Her knee required surgery followed by a lengthy rehabilitation process.

This time around, she was supported by a crew of six women who each swapped in and out at different points, ensuring that Jenny always had two people with her. They followed behind in an RV where Jenny slept each night, as well as a minivan which caught up to Jenny throughout the day to supply her with food, water and clothing.

Jenny went through 11 pairs of running shoes in total, with each pair typically lasting 3-5 days, depending on the road surface. 

Despite wearing “cheap cotton socks” from Walmart, Jenny says she only got a few blisters.

Jenny running beside open fields

However, she experienced plenty of other injuries, including shin splints from day five (despite taking preventative measures after suffering the same in 2019) as well as knee, hamstring and calf problems.

“I also had a few scary falls in the last few days and really banged up my knees,” Jenny said.

It was just whack-a-mole trying to keep all of the accumulating injuries in a steady state so that I could make it to the end.

Jenny says she had dreamed of crossing the USA on foot ever since she was a child. As she grew older, the dream only intensified.

With her first attempt having come to a premature end, she trained intensively for her now-successful second try, running up to 200 miles every week in preparation.

Although she was following the same route that she’d run in 2019 thus was prepared for most potential dangers (e.g. mountain lions or speeding vehicles on Yosemite’s winding roads) Jenny encountered a number of unexpected problems: she endured hail and lightning on a mountain pass in California, navigated miles of clay-like mud in Nebraska, and the RV’s battery died twice.

Jenny running with shin splints

Jenny says the hardest part was running through Nebraska during peak harvest time, where, in addition to the mud, she struggled with 44-mph headwinds, blindingly dusty air, “terrifying” fertilizer trucks, off-leash dogs, lightning storms, and an excruciating calf injury.

Nevada also presented a unique set of challenges, with the desert climate’s extreme temperature fluctuations causing Jenny to fatigue much quicker than usual.

It’s just relentless. Every single day, for 48 straight days, no matter the weather or terrain, no matter how exhausted or injured or sick or discouraged I was, I got up and ran 60 miles.

What made it all worth it for Jenny was crossing George Washington Bridge to see a crowd of friends and family who accompanied her for the final 12 miles through Manhattan.

“I felt so loved, and I really wish every single human being could experience a magical moment like this,” Jenny said.

“I am just so grateful for all of the support. I am so humbled that such an awesome team of six amazing humans were willing to accompany me on this journey and help my dream come true.”

Jenny running in early morning

Although she’s now back to her regular routine of full-time work and looking after her family, Jenny regularly daydreams of future adventures.

“I've never been to New Zealand, but I've heard it's beautiful and the north-south traverse would be an amazing adventure,” she said.

“I've also never been to Alaska, but I have to learn more about polar bears...”

The men’s trans-America record is currently held by Pete Kostelnick (USA), who ran from San Francisco to New York in 42 days 6 hr 30 min in 2016.

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