The England football star was talking to Michael Palin - Monty Python star and veteran of numerous BBC travel shows including one on Brazil.
When Michael asked him about some of the terrifying experiences of the trip, David recalled being left shaken when a frog appeared on his tent - and Michael replied: "You are a wimp really. David Attenborough would have interviewed it."
David admitted: "I am not a big frog fan. It was bright orange and I was told it was pretty dangerous. I was a little bit nervous about that."
The 38-year-old sportsman and underwear model travelled to Rio de Janeiro with three friends before journeying to the remote Yanomami tribe in the 90-minute programme, which will show during the 2014 FIFA World Cup this summer.
David meets Davi Kopenawa
David met the tribe's most prominent spokesperson Davi Kopenawa, who is known as the ‘Dalai Lama of the Rainforest’, and is the first-ever Yanomami shaman to have published a book. Davi told David about the problems facing his tribe, including the illegal gold mining that has been taking place on their land.
David also revealed that one of his goals of the trip was to find somewhere in the world where he was not recognised, and then explain football to someone. He joked: "It is the first time I have ever had to explain what soccer is to anybody apart from Victoria."
The first 30-second clip for the BBC documentary was aired on Friday. In it David's fashion designer wife Victoria joked about David's hair as he shows her and eldest son Brooklyn a map of his planned travels throughout the Amazon rainforest.