Alex Gray's body felt like it was breaking. Having never played a game of American football, having only ever taken a casual interest in the sport through button-pressing Madden on the PlayStation, there he was -- the man who was two days away from playing rugby in the Olympics -- weighed down by pads and helmet all under the baking Florida sun.
Momentary doubts flickered through his mind; he could have stuck to rugby union and lived life in his comfort zone. Instead, he opted for an untrodden path, for a decision that could make or break his sporting career.
After impressing at the NFL training camp in Florida, last week Gray was sat in the NFL's offices in London being told he had been drafted by the Atlanta Falcons as a tight end on a practice squad deal. His whole sporting life flashed in front of his eyes.
Part one of the dream had been achieved.
For the last six months of Gray's life, he has lived in fast-forward. In January he was playing for Yorkshire Carnegie in England's second-tier rugby union competition, the Championship. He was navigating a new position having shifted from the back-row in the forwards, to outside centre in the backs. He was enjoying life, but there was an itch.
"For the past couple of years I've had this crazy love affair with rugby," Gray tells ESPN. "I will always love the game, it is part of my DNA. It's given me some of my happiest moments and provided me with so much pain.
"Everything I've learned through my experiences with rugby have prepared me well for this next step. All signs were pointing for me to give American football a shot ... there was this feeling inside me that it was right."
In rugby Gray had been the nearly man. He captained the England Under-20 side to the Junior World Championship final in 2011, a team that included Mako Vunipola, Owen Farrell, Joe Launchbury and George Ford. He was in line to be a future leader of England's senior side, but in 2013 he shifted to sevens.
As interest in the sport peaked ahead of Rio 2016, Gray was set to be in Team GB's squad, only to suffer a late injury, crushing his dreams of playing in the Olympics. It was hard to take. He re-found a love for the game at Yorkshire Carnegie -- but still something did not feel quite right.
After joking with his agent that his next move should be to NFL, there was a chance call from a scout who was working for the new international player pathway programme. He had been impressed by Gray's natural ability and saw enough potential in him that he could make a dent in American football.
Gray sent off videos of him doing a 40-yard dash, a vertical jump and box jump and he was invited to Florida. Yorkshire, his club team, agreed to let him go on the training camp and it proved to be one of the hardest things he had ever been through.
"Physically it was tough because of the different demands," Gray said. "With professional sport you expect the bumps and bruises but the mental side... for all my life I've been great at rugby from 16 years old, to signing a professional contract at 17, I'd always been a good player. I was almost doing it all with ease.
"But then everything I'd achieved, within two days it was all stripped away from me in Florida. I'd never ever played a snap. It felt like I'd started all over again. It was a mental battle to accept that you aren't going to be as good at this as your previous sport.
"It was humbling going to work again, that's what I wanted though, to have an opportunity where my back was against the wall and it was all or nothing. I had to train every last drop of potential out of those days as I knew that after six weeks if I wasn't up to standard, it'd all go up in smoke. I am proud of what I have achieved."
For six weeks he worked with ex-linebacker Aden Durde and former Indianapolis Colts tight end Dallas Clark. It was a gruelling schedule, training from 7 a.m. until 7 p.m. and then spending the evening studying tapes, playbooks and tactics. He was having to learn a sport from scratch.
"I had those moments where it was 35 degrees and I had the pads and helmets on and my body felt like it was breaking," Gray said. "I was thinking what have I got myself in for. But I kept thinking back to why I was doing it and that light at the end of the tunnel of doing something so special was so unique that no other rugby union player has done it.
"That light at the end of the tunnel kept driving me forward and trying to get as much out of them as possible. Back then I was hating life that's for sure, but now I'm through it and it was so worthwhile."
He impressed to the extent he was one of four players drafted from the pathway programme. He has joined the Falcons practice squad, but he can't play in any of the season games. His involvement this term will be limited to the preseason matches, but the unique nature of the deal means he can't be cut. It's up to him to impress to earn a permanent contract.
He could have stuck to the easy life. At the start of the season he was back living near his family in Bishop Auckland and was enjoying life at outside centre. But he was in cruise control. One phone call last week has changed his life forever. He is now part of the Atlanta Falcons' team, but it is only the start of his American football adventure.
"It's more nervous excitement. It's going to be so, so different," Gray said. "I realise how big an opportunity this is and how life changing it can be. At the very bottom of it, I hope that when I line up alongside someone else that my competitiveness in rugby will go into autopilot in this new sport.
"It does feel like I've done something special, just as far as I've come so far. But this is only the start and it's only going to get crazier from here.
"It was such a long build up those three months in Florida. It was a humbling experience, but to be told that effort had paid off will be something I will never, ever forget."