Traditionally, international sides have played six games across three windows – all of which have featured two fixtures – in September, October and November.
But for the first time this year, the September and October breaks were merged.
Wales’ hopes of coping with the new schedule were not helped by a string of injuries, with stars such as Karl Darlow, Joe Rodon, Dylan Lawlor and Harry Wilson missing the entire camp and David Brooks dropping out of the squad after defeat by Portugal in the opening game.
Bellamy said Dan James was not fit enough to play against Denmark after he was left on the bench at the Cardiff City Stadium, and acknowledged Ben Davies probably should have been rested after he was withdrawn late on.
“If we have a few injuries, which we had more than one or two, they miss four games,” said Bellamy.
“We can deal with two, do you understand? And then the squad will get really tested. The intensity of the squad, the athleticism, really I think [the four-game break] is designed for the elites.
“[They can] say, we can go, we can go, we can turn over these games really, really quickly and we can change, we can change [the team] like for like because we have the numbers. So, it puts a real stress on a lot of us.”