Halle Westfalen (Germany) (AFP) - Nick Kyrgios admitted that his love-hate relationship with tennis means he can only train for a couple of hours before boredom sets in.
The Australian, who reached the ATP Halle grass court semi-finals on Friday with a 6-4, 6-2 win over Spain's Pablo Carreno Busta, labelled his sport "frustrating".
"I get so frustrated at times I have to calm myself down," he said.
Accustomed to running his own practice sessions without bothering to hire a coach, the 27-year-old said he's happy with his own unorthodox procedures.
"In practice, I mainly play points and tiebreakers - I like to keep it fun.
"I need to be having fun on court.I need to do things to make me excited to train, so I use my basketball training.I can't play tennis for more than two hours - it's a bit boring I think."
Kyrgios confessed after reaching his second grass semi-final in as many weeks, that life on tour can be a huge burden.
"You are on your own, an island, you are exposed," the world number 65 said as he moves into position as an outside Wimbledon title threat.
"You can't go to your team and have a sit-down for 30 seconds.
"It's a love-hate relationship for me, for sure.My parents pushed me to play tennis from age seven, it's taken me on a long journey.
"You do get to travel the world every week and experience new cultures and people.Actually, it's a hell of a sport."
On Friday, Kyrgios dug deep into his tennis bag of tricks, treating the Halle crowd to an assortment of 'tweeners', behind-the-leg flick returns and an underarm serve to baffle his Spanish opponent in 69 minutes.
Kyrgios hit 13 aces and broke three times and said he played a standout match against Carreno Busta in their first meeting since 2016.
"I've had some good runs in my career, but I'm really pleased with this performance," the world number 65 said.
"He's Spanish but plays well on all surfaces and hits a flat ball - he's an all-court player.
"I knew I had to be locked in from the back (of the court), I played really well today."
Kyrgios won the sixth game of the opening set with a tiny flick from behind his legs on a return, causing Carreno Busta to sail a return long.
The Australian wild card, who lost in the Stuttgart semis last week to Andy Murray, also played an underarm serve in the sixth game of the second set as he closed in on victory.
"Tennis has been so straight for so long.All I'm doing is an underarm serve.It was not much, but the crowd went crazy," he said.
"They are so used to watching the same thing every time.When someone like me comes and does things differently, that's all it takes."
Kyrgios next takes on Poland's Hubert Hurkacz who defeated Felix Auger-Aliassime 7-6 (7/2), 7-6 (7/4).
Top seed Daniil Medvedev had another easy passage as he defeated Spain's Roberto Bautista Agut 6-2, 6-4.
Medvedev now faces German Oscar Otte, a 4-6, 7-6 (7/5), 6-4 winner over eighth seed Karen Khachanov
