Dr Ian Gillam from Exercise and Sports Science Australia said overseas ventures can cost clubs as much as $850,000.
He said there were more effective training aids in which to invest, with the jury still out on the benefits that come from altitude training.
"That's the figure I got from one AFL club that I spoke to recently, so it's very significant," Gillam told SEN radio on Wednesday morning.
"The cost benefit is not there.
"You think about what you could do with $850,000; you could probably spend it on four or five assistant coaches.
"I just wonder whether the cost could be better improved by spending it on more coaches or improving skills or other things players might actually see an on-going performance in."
The Brisbane Lions, Carlton and Gold Coast are heading to Arizona for two weeks this pre-season while Melbourne players Chris Dawes and Mitch Clark will complete part of their program there.
St Kilda, Essendon and Western Bulldogs players will head to Colorado while North Melbourne has flown to Utah.
Port Adelaide has chosen heat over altitude and will train in Dubai.
However, the pioneers of the overseas training trip Collingwood will not travel this year, with the Pies happy to spend time in their own brand-new altitude facility.
Gillam said a recently published study from Collingwood suggested the players' running performance at sea level improved "by somewhere between 1 and 2 per cent" after a training camp.
But he said those results were short-lived.
"It is certainly important in AFL footy these days – we always look for a 1 to 2 per cent benefit," he said.
"But the issue that I have is the benefit probably lasts a maximum of about four weeks, so if the players go overseas now, the benefit will probably be maintained until about the Christmas break and then most players go off and do limited amounts of training anyway."
Gillam also said there was no scientific evidence to support the Magpies' belief that altitude training enabled players to train harder on return.
He also said he hadn't seen evidence to suggest there could be a cumulative effect from repeat ventures.
"Collingwood may have some in-house information and we all know AFL clubs are fairly sensitive about what they do.
"I've looked at a number of bits of evidence on that and I can't find anything that's actually documented about [players being able to train harder].
"It might be anecdotal but there's certainly no scientific evidence to actually say that's real."
Gillam also poured cold water on the concept of clubs using altitude chambers in Australia to get that training edge.
He said they would have to remain at the recommended altitude environment of around 2500m for 14-16 hours a day for a total of 300 hours, which wasn't practical.
The Bombers and the Saints will have their trips financially offset by funds won by the players for taking part in the recent Virgin Australia short film festival.
The Bulldogs have said the 12 players who will train in Colorado will partially pay their own way as part of a player-driven initiative, as will the Power players with their venture to the United Arab Emirates.
Twitter: @AFL_JenPhelan
