I am looking for the name of a book .,fiction which is the story about
athletes training for a marathon The athletes are from all around the
world and they find at the last stages of their training that the
Olympics will be held in Mexico==a high altitude venue which causes
some real concerns for each.Publication date 1970==ish

Hello.

Your book is probably "The Games" (1968) by Hugh Atkinson.

The novel has all of the elements that describe: marathon runners from
around the world in training, the 1968 Olympics, and concerns about
altitude.

Read these excerpts from a description of the novel from Phillip
Knightley who assisted Atkinson with his research:

"It was clear early on that no one novel could tackle every event in
the Olympic Games, so I decided to concentrate on the most compelling,
challenging and dramatic of all and the one that best encapsulated the
appeal of the Games – the marathon...
All we needed now were some characters to be our marathon runners. How
about an
 Aboriginal stockman, Sunny Pintubi, whose talent is spotted by a
kangaroo shooter when Sunny outruns his ute over a rough outback
track? Now someone from Britain. Harry Hayes, a weedy, little London
athlete with great stamina who takes a job as a milkman so he can
train by running his milk bottles from house to house, street to
street.
 Then the American college boy, Scott Reynolds, a medical freak with
abnormally efficient lungs, running for the glory of the USA; the
fading Czech star, already a gold medal winner and past his prime,
forced back into action by the Communist authorities for political
reasons...

The Games, we decided, would be held in Santa Anna, the capital of a
mythical South American country...
 But Santa Anna, like Mexico City, where the next real-life Games were
to be held, is at 8000 feet and the scarcity of oxygen at that
altitude could well kill off some of the marathon runners. Scott
should be okay because of his freak lungs, but Harry Hayes's trainer
decides that the way for his boy to go is
 to get him used to thin air..."
From: Australia's News Limited
http://archive.sport.news.com.au/olympics/ticketmags/word_games/wg17.htm

Copies are available from used book dealers such as those listed on
Abebooks.com:
http://dogbert.abebooks.com/servlet/BookDetailsPL?bi=44787250

And Alibris:
http://www.alibris.com/search/detail.cfm?bid=8008942881

search strategy: abebooks, olympics, novel

I hope this helps.

Top Stuff---thats the one !!!!!!!Thank you, Jim