AMMAN, Jordan (AP) After 16 hours without food or water, Moath al-Khawaldeh laces up pink training shoes and begins working up a sweat sprinting across a track in the Jordanian capital of Amman.
Running slower than his 4:19 mile best, al-Khawaldeh grimaces on the final lap and looks to the golden sky of sunset.
The 27-year-old is on a multiyear quest to run in the 2020 Tokyo Summer Olympics.
With guidance from nutritionists and coaches in Jordan and the U.S., the runner follows a training program that has lowered his body fat, cut his marathon time by 15 minutes and has enabled him to train while fasting during the Islamic holy month of Ramadan.
''I forget that I'm fasting and I just do it,'' he said. ''I feel that Ramadan is a one-month marathon.''
Believers abstain from eating and drinking from dawn to dusk in one of Islam's central tenets. Fasting aims to remind Muslims of the hunger pains of the poor.
Al-Khawaldeh said fasting also builds mental strength.
''God will never change a person who hasn't changed themselves,'' he said, quoting the Muslim holy book, or Quran. For him training, or making the best of one's ability, is a form of faith just like fasting.
Fasting for a month changes sleep cycles, body temperature, hormone and blood sugar levels - all of which can reduce athletic performance if not properly handled, said Asma Aloui, an associate professor at Gafsa University in Tunisia.
Her research on fasting athletes playing soccer and judo suggests that those who drink enough water, eat, sleep and train properly can maintain their speeds and strength.
A starving body absorbs food differently as it adapts to a lack of minerals, nutrients and water, said al-Khawaldeh's nutrition coach Aseel al-Saleh.
After a few days of fasting, an athlete's body switches quickly into ''deficiency mode'' to build up fat reserves, al-Saleh said in her office at DNA, a fitness center in Amman.
''The funny thing about human physiology is that it can't differentiate between dietary restriction and starvation. It just can't, it shuts down,'' she said.
On the road to Tokyo, Al-Khawaldeh can't afford catabolism, or muscle loss, so he and al-Saleh crafted an athlete's Ramadan diet.
Instead of five small meals a day, he switched to eating the holy month's traditional two meals loaded with vegetables, lean protein and nutritional supplements like omega-3 fatty acids, potassium, fish oil and branch-chain amino acids.
During the day, he works as a program officer for the Jordanian peace-building nonprofit Generations for Peace. He naps after work, then rises for the first training session, which ends with the sundown call to prayer - the signal that it's time to eat.
Al-Khawaldeh eats a few dates and drinks water at the track, then heads home to a ''sufra,'' or Ramadan table laden with foods selected to recover nutrients and hydration lost during the day's fast.
At the post-sundown meal, or iftar, he typically eats chicken on brown rice and steamed vegetables and washes it down with a smoothie of skim milk, dates, bananas, almonds and protein powder.
The meal contains easily digested nutrients and proteins, while the second meal, suhour, eaten before sunrise contains slow-burning proteins.
People often gain weight during Ramadan because the day's hunger drives many to gorge on fatty foods and sugary drinks, said al-Saleh, the nutrition coach. Many also cut sleep to enjoy social gatherings often surrounded by calorie-heavy snacks.
But Al-Khawaldeh interprets Ramadan's tradition to his advantage with a support network of people helping him eat, sleep, hydrate and train safely.
Two years ago, al-Khawaldeh began working with Lee Troop, a high performance coach at the Boulder Track Club in Colorado, a nonprofit running club and training center. At the time, he could run a marathon's 42 kilometers or 26.2 miles in 2 hours and 40 minutes, but he needed to lower that to 2:18:59 to qualify for the Olympics.
With Troop's regimen and guidance, al-Khawaldeh got faster -- 2:33:36 in Vienna, 2:30:57 in Berlin and 2:27:35 in Hamburg. He still faces thousands of training miles over the next three years to try to shave nearly 10 more minutes off his time to get to Tokyo.
Troop said the key to long-term success in long-distance running is determination and steady work. Al-Khawaldeh's program during Ramadan left the runner leaner, but not faster, yet the mental exercise of fasting is preparing him well for Tokyo, the coach said.
''His work ethic is second to none,'' Troop said. ''He's been very resilient and the key for success is that long-term development of every day, week, month and year.''
If al-Khawaldeh qualifies for Tokyo, he will be only the second Jordanian to ever run in the event, according to the Jordan Olympic Committee's website.
Jordan has competed in the Summer Olympics since 1980, mainly in skeet shooting and taekwondo. Five Jordanians will compete in martial arts, boxing and the triathlon in this year's games in Brazil.
The centerpiece of al-Khawaldeh's Ramadan training is a midnight run, monitored and timed by Osama al-Qattan, 52, a Jordanian ultra-marathon runner.
After a recent night session, al-Qattan drives while al-Khawaldeh relaxes in the backseat, sipping water and a protein shake. ''Running is 30 percent physical and 70 percent mental,'' the older runner said. ''And Moath has a strong will.''
Al-Khawaldeh said Ramadan is a welcome test of strength.
''It's a great feeling, the sense that you have that power in your body that you didn't know was there but comes out during Ramadan,'' he said.