Former Australian cricketer May, now chief executive of the Federation of International Cricketers' Associations, described the Future Tours Programme (FTP) as "a disaster" in the July issue of the Wisden Cricketer magazine.
"The Future Tours Programme is a disaster because it puts no upper limit on the amount of cricket that can be scheduled," May told the leading cricket magazine.
"All the ICC has delivered is a minimum guideline for the amount of cricket. There is nothing to stop individual boards arranging extra series on top of that in the FTP."
Kallis told Reuters he agreed with May's comments.
"The amount of cricket we play is way too much. They need to cut down the Future Tours Programme. Otherwise teams are going to end up resting their top players if it stays the way it is. But the public want to see the best players, so it's a big problem," Kallis said.
May warned that the players could be on the brink of strike action if the ICC did not cut back on the schedule and impose maximum limits on the amount of cricket foisted on the top players.
"There are five or six guys in the five leading sides in the world who play Tests and ODIs and they are being flogged. They are the ones who make the difference between a 10,000 crowd and a sell-out.
"If there is anything that will force the players to take the ultimate step of industrial action, it's the Future Tours Programme. I'm not saying it is about to happen but the punishing year-round commitments are a 'play-travel-play-travel-play-fall over' schedule," May said.
Kallis said all-rounders were receiving a particularly raw deal from the ICC.
"For all-rounders its definitely too hard a schedule. It's killing them.
"And young players won't want to be an all-rounder if they see how quickly you get worn out. It would be better to go the route of being a specialist batsman or bowler," Kallis said.
May even raised the possibility of players solving the problem of too much cricket by turning to performance-enhancing drugs.
"You only have to look at the doping record in baseball to see that recovery, not enhanced power, is the motivation for most drug misuse. The more we push our players, the more they might look at options," May said.
Kallis called for an investigation into what would be a reasonable workload for the players.
"We need scientific research on how many matches would be ideal. There needs to be a balance and I'm sure we need less cricket.
"It's overkill - the public are already saying that," Kallis added.
