Kyle Walker feels it was a gruelling first pre-season under Mauricio Pochettino which laid the groundwork for Tottenham to challenge for the Premier League title.
Spurs, five points behind shock leaders Leicester City with four matches of the season to go, are firmly in contention to win what would be their first league championship since 1960-61.
According to defender Walker, a brutal period of physical preparation orchestrated by uncompromising manager Pochettino after his arrival in 2014 has been key to the London side's development, with the Premier League's traditional heavyweights - including rivals Arsenal - trailing in their wake this season.
He told the Telegraph: "I'm not going to lie. At the start it was horrible. Horrible.
"When you reach the first team as a professional, it's kind of like, 'If you want go and do gym, do gym. If you don't, you don't have to'. But when he came in, gym was compulsory.
"We have got four games left, and we are still running almost every other team off the pitch. The only team close to us, if I remember correctly, is Bournemouth.
"That's what I meant about doing the basics right. We can all play football, but one of the basics of this game is that you need to run about and work for each other. That's what's pushed us on to the next level."
Walker, who signed for Spurs from Sheffield United in 2009, believes the team's work-rate under Pochettino makes them a superior force to the side that reached the Champions League quarter-finals under Harry Redknapp in 2010-11.
"Gareth Bale, Luka Modric, Rafael van der Vaart, Ledley King - you would probably have chosen that team on paper," said the England international, 25.
"But for work ethic and team spirit, it's this team all day long. We have set the bar now and everything below this bar is unacceptable.
"I have been here six years and it's the closest I've ever come to being a Premier League champion - that is why I signed for Tottenham."