Thwock! A final tennis ball fizzes into the service area. The young tennis player has been on court for three hours and has been told at last to call it a day.
The idea of a morning dedicated to sport would certainly appeal to most teenagers, but Georgina Bastick's training session is pretty gruelling. Besides, the 17-year-old now has an hour and a half-long economics lesson to attend.
Georgina is a student at Freedom School, recently established by former UK number one women's doubles player Helen Crook to cater for promising young athletes.
The independent school structures its pupils' days so that they spend as much time as they need training in their chosen sport. But it also provides a "normal" education to give them as much chance of succeeding outside sport, should their dreams of becoming the next Andy Murray come to nothing.
Located in Chingford, Essex, the school was set up in response to what Ms Crook describes as the "inflexible structure" of state schools. The problem is, she says, that if a child shows promise in a sport, the majority of the training has to be fitted in around school hours.
According to Ms Crook, mainstream schools give far too much academic work to their pupils, especially those who show sporting potential, and this can lead them to abandon their studies altogether.
"Most schools these days have children studying 10 or even 11 GCSEs when they need far fewer to get into university," she says. "It's crazy, and actually creates an incentive for children whose main focus is sports, or the arts, to drop out of school and abandon academic qualifications altogether.
"The number of children dropping out and becoming full-time sports people has never been higher. On the surface, this is great - if we have a UK Wimbledon winner in 15 years' time we'll all be patting ourselves on the back and saying job done. After all, who wouldn't like to emulate Andy Murray's success?
"But think about all those others who fall through the net? What will happen to those twentysomethings without anything to fall back on and no direction to take?"
Freedom School's answer is to provide its pupils with the minimum needed to get into university. The intake starts in Year 9, where pupils take three GCSEs in their first year, and another three in the second. Students then go on to take two or three A-levels over the final two years. But, unlike state schools, the teaching revolves around the child's training.
The usual school day consists of two hours' teaching in an allocated subject. This is followed by five hours of coaching in the sport in which they excel. The day finishes with a one or two-hour conditioning and physiotherapy session.
The idea is that academic lessons are as intensive as the training sessions. The class size never exceeds eight pupils, meaning that more of the syllabus can be covered in a shorter time.
The school currently has five pupils awaiting A-level results and is set to enrol another eight of GCSE age. There are five teachers - generally supply staff or private-school teachers who combine their main jobs with teaching at Freedom School. Each teaches their specialist subject.
However, the school prides itself on being as flexible as the pupil needs it to be. If it does not cater for a particular subject that the student wants to pursue, it simply hires the relevant teacher.
All this comes at a price, of course. But its fees of pound;4,000 a year are around one third of those at other private schools in the area. The school hopes to provide parents with an alternative to more drastic measures, such as taking the child out of education altogether.
Georgina Bastick is an A-level pupil at the school. She had a stint at being home schooled as her parents tried to cater for her tennis playing. But she says it did not work out.
"We tried home schooling but it was a bit of a disaster," she says. "I basically put a disc into my computer and tried to learn that way. (But) there was no help, and no advice."
But Freedom School says it gives budding athletes the structure they need. Tom Reynolds, also 17, joined the school after completing his GCSEs. His day is split perfectly to allow him to train hard but also get the lessons he needs.
"The morning usually starts with a couple of hours of tennis and a 30- minute fitness session," he says. "We then break for lunch. After that, I have three hours of lessons. I take English literature, economics and PE. I will have two subjects in three hours. The day then finishes off with another fitness session.
"The teaching is better because it's all basically one-to-one, and it makes it easier for me to play tennis. I can take it more seriously, and I have improved massively since joining."
Jo Ward is both a tennis coach and English literature teacher at the school. A former tennis pro, she knows how difficult it can be to find the time to play tennis in the usual state school system.
And she sees at first hand the difficulties young athletes face trying to achieve in their chosen sport while fitting in their school work.
"I am coaching a boy who is 12 and at his age and at his standard he needs to be playing up to 20 hours a week," she says. "He's doing nine or 10 subjects, with nine or 10 sets of homework in some subjects he has no interest in pursuing. He needs to be doing subjects he's good at. By diluting his time all you do is get less success in all of the subjects.
"What's more, he lives an hour from here. He gets off the court at 9pm and condenses those 20 hours a week into such a small space of time. On a Monday, he'll be on court for five hours. He's getting home at 10pm at night. You worry whether the kid is getting any kind of balanced life."
Ms Ward says the UK doesn't compete with other countries such as the US and Russia and even France and Spain when it comes to giving its school children the right balance of sport and academia.
"In the US they have the perfect balance between work and sport," she says. "They accommodate the sport in the academic day. In France, we spoke to schools which give the whole of Wednesday off to play sport."
The lack of a balance to accommodate sport in a school day is a peculiarly British problem, it seems. As a nation, we are fanatical sports fans, but we do very little to give promising athletes the chance - or the cash - to shine on a world stage.
The only reason footballers can compete globally is because the players are scooped up by top clubs before their voices have even broken. But the standard of education they receive is often of debatable quality.
Instead, Freedom School advises its pupils to look at the alternatives, even if those are abroad.
Ms Ward says: "With our school, you don't need to sacrifice anything really. You get a bespoke education in small classes in less time and still achieve good results. This model will work with any sport, and it can even work with music or art.
"But our advice is to get your A-levels, give your sport a go for a year, and then go to university. We often say look to America."
More than 1,000 US universities offer sports scholarships, and the country ploughs millions - if not billions - of dollars into college sport.
"The US system is amazing, especially for British athletes, and it's particularly good for women," Ms Ward says. "There's a piece of legislation that stipulates that a US college has to give as many sport scholarships for women as it does for men. And because you have so many male scholarships - for the (American) football teams, basketball teams etc - the opportunities for individual women's sports, such as tennis, are fantastic."
It is advice Georgina and Tom hope to follow. Both want to continue with their sport to see how far it can take them. The idea that they can enjoy a top-class education off the back of their talent gives added incentive.
"It's imperative to have something to fall back on," Ms Ward says. "If you fail at tennis and then have nothing to turn to, you're going to go through life feeling like a total failure, aren't you?
"I was national ladies champion and played at Wimbledon. I travelled the world and had a fantastic life, but I was forced to retire at 25 and I always felt unfulfilled academically.
"But if you have a bash at your sport and it doesn't work out, you can at least go on to get a degree and be successful in something else."