American Ryan Hall will not participate in the 2013 Boston Marathon, race sponsor John Hancock Financial announced on Wednesday.

According to a press release, “Hall missed crucial training due to a quadriceps strain.” Hall holds the American record at the Boston Marathon, a 2:04.58 in 2011.

Hall expressed disappointment on Twitter. Said Hall “Heart breaking to have to pull out of Boston. Want to thank all my sponsors and supporters for sticking by me through it all.”

Other previously announced elite male runners who have also cancelled because of injury include Moses Mosop, Shami Dawit, Eric Gillis, and Lucas Rotich. Two elite women also dropped out due to “lack of fitness” – Asefelech Mergia Medessa and Karolina Jarzynska.