Rachel Cawthorn admitted she was so nervous ahead of her kayak final that she was sick.
The 23-year-old British athlete finished sixth in the women's K1 500 metres, behind Hungary's Danuta Kozak, who claimed gold.
She said: "It was hard not think about that this morning and last night. I didn't really get any breakfast in, well I did, but it came out. I was trying to think about the process and use the crowd at the end."
After winning her heat, Cawthorn was in the hunt for a medal. But she said the experience of competing in her first Olympics will stand her in good stead.
Cawthorn, from Guildford, Surrey, said: "I just wish I could have finished a bit further up. After what I did in the heat and semi, I knew I was better than what I thought I was. With all the crowd here, it makes you want to win a medal even more to experience it even more. I am a bit disappointed to finish where I did."
She added: "It just seemed to be over really quickly. All that training and all that time, just so much thinking about it. It is now just done and I don't know what to think.
"I had a good start and I think that in the next 100m I just didn't nail as well as I did before. I probably needed to be a bit braver, to just hit it. I was probably just a bit too far down to come back at the end.
"I kind of get the whole Olympic cycle thing a bit more now that I have raced the finished product and it makes me more aware going in to the next cycle why you train those four years.
"It was really incredible out there and this is where you want to be at your best.
"I just tried to think of it as just another race but after the K4 yesterday being so close to a medal and then seeing what I could do in the semis, made me know that I was in with a chance, that I wasn't miles off.