England wing Tommy Freeman and Ireland prop Tadhg Furlong both said similar after being involved in last summer’s Lions tour of Australia.
“Without realising it, I think I was tired,” Freeman said of his return to club side Northampton.
“My body felt like I was OK to go and I was saying to coaches ‘Yeah I’m fine, I’m fine’. I just think mentally it was a bit more of a struggle.”
Three-time Lion Furlong said: “Everything maybe seems insignificant the year after.”
France’s players may not have that much sympathy. A campaign in their domestic top flight – the Top 14 – can stretch to 29 matches.
The equivalent figure for the English Prem and the United Rugby Championship is 20 and 21 matches respectively.
However, unlike with the Home Nations, France usually rest their top stars for their summer tours.
While the Lions were touring Australia, across the Tasman Sea a France side took on New Zealand in a three-Test series without the likes of Louis Bielle-Biarrey, Matthieu Jalibert or Charles Ollivon.
Despite objections from their Kiwi hosts, concerned about the impact on ticket sales, France stuck to their policy as a second-string side suffered a 3-0 series defeat.
Ireland are adept at managing their stars’ overall workloads. For instance, Leinster and Ireland hooker Dan Sheehan has made only three starts for his province so far this season.
But Warburton believes that not all games are equal. In his opinion, the Test stages demands more of players.
“I think there’s something about playing international rugby – there’s only so many times I think you can play an international game of that magnitude, emotionally, in a year,” he said.
“The Lions tour obviously eats into that quota and I think it’s a massive part of it.”
The Six Nations’ regular calendar cycle might also play a part. In even-numbered years – in which every post-Lions Six Nations take place – France have three home games, rather than two.
Their home matches include meetings with Ireland and England, often title rivals.
France bookended their Six Nations campaign with victories against those two in Paris this year, crucial results in their championship success.