Image copyright Getty Images

A Wimbledon win may, at least in part, be down to pumping iron in the gym, according to UK researchers who say the most successful elite male players of modern times tend to be more muscular.

Over four decades, men's champions have morphed from lean endurance sportsmen to brawny power-trained athletes, the Wolverhampton University pair say.

According to them, bulk gives a competitive edge for stronger shots.

It suggests Andy Murray has a good chance of winning the contest again.

But so too does Novak Djokovic.

The researchers studied the physique of players in grand slam tournaments.

Image caption Bjorn Borg looking lean and mean

Across the majors they looked at - the Australian Open, the French Open, Wimbledon and the US Open from 1982 to 2011 - a trend emerged in the male players who reached round three or more of the tournaments.

Over time, the players have become heavier and more muscular.

And the amount of muscle a player has appears to boost his chances of winning.

The researchers, Prof Alan Nevill and PhD student Adam Gale-Watts, found a significantly steeper rise in body mass (muscle rather than fat) of the most successful players compared with less successful ones.

The rise began in the 1980s, speeding up in the 1990s and peaking around 2009 - the year when Scottish player Andy Murray was seeded world number two.

At the same time, leanness of players declined, they report in the European Journal of Sports Science.

Image copyright PA Image caption Fred Perry cut a slender frame

Prof Nevill says: "Four decades ago, tennis players were quite lean and thin. But they've got more muscle now.

"If you look at Andy Murray at the age of 17, he was quite a skinny little lad.

"He's bulked up since then, and I think that's been the secret of his success over the last four to five years."

Prof Nevill says high levels of muscle mass and low levels of body fat afford competitive advantage, meaning players can generate greater power behind shots, while being speedy and agile on the court.

But he says there may be a trade-off - putting in long hours in the gym and on court can lead to injuries.

Image copyright AFP/Getty Image caption Djokovic also has power on his side

Both Novak Djokovic and Andy Murray have experienced periods of injury in recent years, although both appear on top form for this year's Wimbledon contest.

Prof Nevill says his money is on Djokovic to win.

But he adds: "Murray might get to the final again. I hope so anyway."

The researchers did not study female tennis players, but Prof Nevill suspects the game is slightly different for women.

Image copyright AP Image caption Serena Williams is ranked number one for women's singles tennis

He says: "Serena Williams is a very powerful lady, and some of the other ladies can't survive on a court with her because of the power.

"But it's a balance between skill and power, and the skill factor in ladies' tennis is probably slightly higher."

The researchers have also studied what might be the perfect physique for other sports.

And when it comes to sprinting and football, it would appear being lean wins the day.

Men's and women's singles rankings as of 27 June 2016 1. Novak Djokovic (Ser) 1. Serena Williams (US) 2. Andy Murray (GB) 2. Garbine Muguruza (Spa) 3. Roger Federer (Swi) 3. Agnieszka Radwanska (Pol) 4. Rafael Nadal (Spa) 4. Angelique Kerber (Ger) 5. Stanislas Wawrinka (Swi) 5. Simona Halep (Rom)

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