|Andy Murray's Greatest Hits|
|BBC One: 4 July (13:15 BST) and 5 July (1400)|
|Watch live on BBC TV, Connected TV, BBC Sport website & app, catch up on iPlayer|
Andy Murray says he is now serving as hard as he did when he was in his mid-20s, which is "good news" for his body as he rebuilds his injury-hit career.
The Scot, 33, reached the semi-finals of the Battle of Brits last week in his first event for seven months and was "pleasantly surprised" by his tennis.
"I just wasn't able to sustain it for long enough," he said in an interview for this weekend's Andy Murray's Greatest Hits programmes on BBC One.
"At times I played really well."
Former world number one Murray had career-saving hip surgery in January 2019 after pain had dogged him for a number of years.
He says the resurfacing operation has improved his movement so much that he is able to regain the power in his serve from a time when he was at the top of the sport.
"For the two years before I had the operation I couldn't extend my leg properly, so my right leg would always bend when I went to extend it and that was affecting my serve a lot. I had to change my ball toss and was not able to drive up properly," added Murray.
"But now, because it does extend properly, I am able to serve well again and am able to serve as hard as I was in my mid-20s, which given I didn't know I was going to be able to play again has been really positive.
"Obviously when you are able to serve bigger and harder, it means more shorter points - and that means good news for the body and the hip. The harder I serve, the better it is for my other hip I guess."
The ATP tour, which has been suspended since March because of the coronavirus pandemic, will resume next month. Murray's first event will be the Washington Open on 14 August before the US Open starts on 31 August.
The three-time Grand Slam champion will no longer play tournaments in back-to-back weeks as he bids to preserve his body and he says he "doesn't love" the fact that the rearranged French Open will come just two weeks after the US Open.
Murray is particularly unhappy that French Open organisers unilaterally decided when to hold the clay-court Grand Slam that usually takes place in May.
"Getting the US Open and the French Open played this year is a good thing, I think. It's positive, I just don't like the way the French Open went about scheduling their event," he said.
"But we're going to have to go back to playing at some stage. The most important thing is that the events are safe."