HAMILTON, Bermuda (Reuters) - Sailors usually have cast iron stomachs, but in the quest to retain the America's Cup, Oracle Team USA are leaving nothing to chance.
They are using advances in gut testing to boost health and fitness as they gear up to battle back against New Zealand and win the oldest trophy in international sport.
Improving their internal health has improved the number of days the team can sail and train and cut illness rates as they ramp up training in a bid to cut a 3-0 New Zealand lead.
Oracle's gains could also have implications for other sports, businesses and general health and wellbeing as the focus shifts to preventative medicine.
A chance meeting in Bermuda between Dr Erika Angle, CEO and co-founder of Ixcela, a biotechnology firm which has developed microbiome tests, and Scott Tindal, Oracle's head physio and team nutritionist, started the U.S. team's foray into stomach health.
The gut balances of Oracle's 13 sailors were tested using Ixcela's kit. Their diet was modified based on the results and they also took tailored supplements and probiotics.
"We saw a significantly large improvement in performance. This is the front end of the wave," Angle said.
Oracle experienced a 30 percent reduction in the incidence of upper respiratory tract infections, a 47.5 percent gain in the number of sailing days lost to illness and a 54 percent improvement in the number of training days lost.
"It's only going to get better with different tests for professional sports and individuals," Tindal said.
One sailor who suffered from 17 upper respiratory tract infections had that number cut to one and another had 12 similar illnesses reduced to three.
"This doesn't stop you from getting sick, but it does reduce the incidence and severity. You do get sick, but you bounce back quicker, that's powerful and significant in a sporting context," Tindal said.
The introduction of 50-foot catamarans that "fly" on hydrofoils into the America's Cup has increased the physical demands on sailors who are operating at 90 percent plus heart rates during the races as they grind winches by hand or cycle on bikes to move massive wing sails.
"We've not seen these levels of fitness in sailing before," Tindal said.
Oracle is putting in punishingly long days on the water ahead of the resumption of racing on Saturday, leaving the sailors shaking before team coaches helped them rebalance their energy.
This compares to 20-minute races that burn around 500 calories per sailor.
Editing by Ed Osmond