Real Madrid star Gareth Bale believes the lack of a mid-season break and relentless domestic competition leaves Premier League sides burnt out when it comes to competing for European honours.
Bale has won the Champions League twice since leaving Tottenham for the Spanish capital in 2013 and sees the benefits of resting up at Christmas in order to be fresh at the business end of the campaign.
Madrid hold a 3-1 advantage over Napoli ahead of Tuesday's last-16 match at Stadio San Paolo, while Arsenal will kick-off at the same time, staring down the barrel of elimination due to a 5-1 deficit to Bayern Munich.
Manchester City lead 5-3 against Monaco after a first-leg thriller and Leicester are 2-1 down to Sevilla, and Bale feels the dwindling Premier League contingent will once again struggle to challenge the continent's elite.
"I think I know why – but you can't change it. It's the league itself. In every Premier League game you have to be at 100 per cent for 90 minutes or you lose," said Bale, as quoted by The Sun.
"Also in Spain, you can be up at half-time against the bottom club and you can take your foot off the gas. You can take people off.
"If you try for only 45 minutes you won't win a match in the Premier League. Obviously, we still play but it's not at the same 110 per cent intensity.
"And the winter break is massive. In England you'll play four or five games and we don't play any. You don't get many rest days and it really does burn you out for a long time."
While he still marvels at the competitive edge in the Premier League, Bale believes the sharp end of La Liga, with the likes of Atletico Madrid and Europa League champions Sevilla pushing Madrid and Clasico rivals Barcelona, boasts a superior quality of football.
"In terms of one-to-20 the Premier League is the closest. On any given day, 20th can beat top. Here, not so much. It's a bigger gap.
"But I feel the top six or seven in Spain is really strong and in European competition you've obviously got Real Madrid and Barcelona, Atletico Madrid have been to two finals and Sevilla have won the three Europa Leagues.
"The Premier League is by far the most competitive - but the teams that always perform in Europe are from Spain."