On Wednesday, however, the Belgian abruptly announced her retirement from tennis at the age of 25.

Her coach of 12 years, Carlos Rodriguez, said that Henin had simply lost the "fire that drove her to success."

The timing of her retirement was totally unexpected since her favourite tournament, the French Open, was less than two weeks away and as the 2007 champion she would have been expected defend her title.

Yet, like he compatriot Kim Clijsters who quit last year aged 23, Henin decided she had had enough.

Although Americans Tracy Austin and Andrea Jaeger provided the template for tennis burnout more than two decades ago, it seems that measures introduced by the sport's governors are still failing to protect the players' well-being.

Australian Open champion Maria Sharapova this week accused the ruling body of women's tennis (WTA) of being ignorant of the players' needs.

"Over the last few years all the players have been to numerous mandatory (WTA) meetings and sometimes you go back feeling you are talking about the same things and having the same issues and your voice is never being heard," the Russian said.

Sharapova's anger was prompted by the WTA's decision to fit in a photoshoot with the players on the eve of this week's Italian Open.

REPEATEDLY COMPLAINED

Her concerns were echoed by men's world number two Rafael Nadal, who has repeatedly complained about this year's congested men's calendar.

Because the Olympics needed to be slotted into the schedule in August, the three claycourt Masters events -- in Monte Carlo, Rome and Hamburg -- have been crammed into four weeks.

"The calendar is impossible," Nadal said.

"I have some email conversations with these people (ATP) but it is true that they end up doing what they like and I am getting tired of it all."

However, both the ATP and WTA have made plans to shorten the season from 2009.

While the ATP said reforms to the calendar would offer players "a fairer and healthier schedule", the WTA's new "Roadmap" plan will trim the current 25 Tier I and II events to 20 premium tournaments anchored by four mandatory events.