After graduating from the academy, Eastler spent his first assignment with the World Class Athlete Program in
Chula Vista, California. Training full-time for the
2000 Summer Olympics in
Sydney, Australia, he finished in second place at the U.S. Olympic Trials, but was denied a spot on the United States team, as he failed to achieve an A-qualifying standard time. Eastler stopped race walking for over a year until he was reassigned to
Francis E. Warren Air Force Base in
Cheyenne, Wyoming. Because of his outstanding achievement in the sport, Eastler was named the Male Athlete of the Year by the U.S. Air Force. Eastler qualified for the second time at the
2004 U.S. Olympic Trials in
Sacramento, California, where he finished third in the 20 km race walk, with a time of 1:28:39. Having achieved an A-standard time from the IAAF World Championships, he earned a spot on the United States team for his first Olympics. At the
2004 Summer Olympics, Eastler competed as a member of the U.S. track and field team in the
men's 20 km race walk, along with his teammates
Tim Seaman and
John Nunn. He finished twenty-first in this event by three seconds behind Seaman, with a time of 1:25:20. In 2006, Eastler set a record-breaking time of 2:12:53 at the U.S. 30-km Race Walk Championships in Chula Vista, California. He also claimed his second U.S. championship title, and posted three fastest times by an American in the 20 km race walk. Eastler ended his season as being ranked no. 1 in the United States at the distance for the second time in his career, and the first since 2003. In 2007, Eastler established himself as America's preeminent male race walker. He won his third consecutive title in the 20 km and added the 50 km title, with a personal best time of 4:05:44 at the U.S. Outdoor Track & Field Championships. He also competed at the
IAAF World Championships in
Osaka, Japan, where he finished twenty-eighth in the
20 km race walk, and thirty-first in the
50 km, posting his time of 1:28:29 and 4:31:52, respectively. Eastler earned a spot on the United States team for the
2008 Summer Olympics in
Beijing, by winning the race walk at the
U.S. Olympic Trials in
Eugene, Oregon, with an A-standard time of 1:22:56. Eastler competed as a lone athlete in the
men's 20 km race walk, where he successfully finished the race in forty-third place by nineteen seconds behind Kazakhstan's
Rustam Kuvatov, with a time of 1:28:44. ==Personal bests==