Professional triathlete Timothy O'Donnell made history on Oct. 12 when he had the fastest finish ever for an American at the Ironman World Championship in Kona, Hawaii.
Despite coming in second, O'Donnell covered the 2.4-mile swim, 112-mile bike and 26.2-mile run in seven hours, 59 minutes and 40 seconds, his — and the U.S.'s — first sub-eight hour performance. (Germany's Jan Frodeno came in first with a time of seven hours, 51 minutes and 13 seconds.)
Prior to O'Donnell's finish, the U.S. had not had a podium finisher at the event since 2016.
O'Donnell, who has been competing in triathlons for about 17 years, says he is still learning about what works and what doesn't work for his performance after every race.
"Every year, I'm becoming a new athlete," O'Donnell tells CNBC Make It. "I'm 39 and I just had my best performance at Kona and the best performance for an American ever, so you are always looking at other ways to become a better athlete."
O'Donnell cites nutrition as a key component of his training routine, and in addition to practice and conditioning, he uses "biohacks."
For example, O'Donnell uses a hyperbaric chamber for recovery after really hard training days. The technique has also gained a following among NFL players and celebrities over recent years — Jacksonville Jaguars quarterback Nick Foles uses one, for example, as does self help guru Tony Robbins. Inside the chamber, air pressure is increased to three times higher than normal, pumping high levels of pure oxygen into the lungs. According to the Mayo Clinic, the technique helps to fight bacteria in the body and promote healing, but there are also risks associated with the treatment.
O'Donnell also uses a transcranial direct-current stimulation (tDSC) device to improve muscle memory, strength and endurance before a big workout. He uses the Halo Sport headset, for which he is a paid spokesperson. According to the company's website, the $399 headset sends electrical currents that stimulate specific parts of the brain to either increase or decrease excitability. Studies have found that tDSC can improve memory, boost endurance and even reduce prejudice in healthy individuals. Some doctors, however have warned against using the technology, especially do-it-yourself kits, as there are still a lot of unknowns. (Halo Sport is not approved by the Federal Drug Administration for medical applications but has been ruled as a "general wellness" device by the agency.)
On average, O'Donnell who trains all year long, will work out about five hours a day with one rest day per week (usually just a light swim) and a complete day off every other (or every third) week. But he does ramp up his training a few months before the Ironman Triathlon.
Here's a look at O'Donnell's daily training routine.
5:45 a.m.: O'Donnell's wakes up and makes coffee. Then he does a 15-minute session on a $3,250 Addaday BioChair massage chair. The chair has a setting designed to prep triathletes before big runs by focusing on certain muscles. He then has a Ucan chocolate bar with peanut butter. O'Donnell is a paid spokesperson for both Addaday and Ucan.
6:40 a.m: The first workout of O'Donnell's day is a long run, typically about 10 miles in under 60 minutes. During the last few miles, he tries to average five minutes and 20 seconds per mile. He runs this with his coach and sometimes his triathlete teammates during the training season.
8:15 a.m.: Post run, O'Donnell heads to his fitness club, where he has a Ucan shake before starting his swim session. O'Donnell swims approximately 6,000 yards, which typically lasts 90 minutes.
10:30 a.m.: After his swim, O'Donnell spends 15 minutes relaxing in a hot tub with his 2-year-old daughter, Izzy, as her swim lesson finishes at around the same time.
11:00 a.m.: O'Donnell lifts weights for 45 minutes with his strength coach.
11:45 a.m.: O'Donnell either has lunch at the fitness club or heads home. He typically eats scrambled eggs with brown rice, black beans and spinach. He also has another cup of coffee while he answers emails and does administrative work at home. After relaxing for about an hour, he jumps back his massage chair for 15 minutes using the setting for cycling.
1:30 p.m: O'Donnell does a two-hour bike ride, then has a post-ride fruit and Ucan supplement smoothie.
4:00 p.m.: O'Donnell gets a 90-minute professional massage.
5:30 p.m.: After Dinner with his family — usually some sort of meat with mixed veggies and a starch — he spends the rest of the evening with his daughter, until he reads her bedtime stories and puts her to sleep at 8 p.m.
8:30 p.m.: O'Donnell spends an hour finishing up administrative work and emails.
10:00 p.m.: O'Donnell heads to bed.
Like this story? Like CNBC Make It on Facebook.