Olympic silver medallist Michael Jamieson revealed on Saturday that he had to have his heart re-started on Wednesday.
The Bath Intensive Training Centre swimmer was upbeat about the news which he announced on Twitter.
The 25-year-old said on mj88live: "Long week! My heart was restarted on Wednesday AM, pushing bit too hard at training on Tuesday haha. Docs & nursing staff at RUH/EIS...have been amazing. I'm back home & cleared to train! Specialist said he's only seen this 3 times, all Olympic medallists - pretty cool! p\u001F
"...not really sure the reasons behind it happening but I went into an irregular beat after reaching 203 heart rate in a session (max is 193)."
A British Swimming spokesman said: "Michael experienced a minor irregularity in his heart rhythm this week and was seen immediately by specialists.
"He has been cleared to train following medical treatment and is already back in the water."