PULSE racing and sweat dripping, I sprint across a tennis court at Neilson's Messini Beachclub on southern Greece's Peloponnese peninsula.
Former British tennis pro Mark Petchey is putting me through my paces, challenging me to return shots from the net and the back of the court, while running in an X axis.
In the baking midday sun, it's not long before I'm worn out.
Realising I need a break, Mark calls time on our drill. I'm anxious I haven't been working hard enough, but my coach's generous spirit and infinite patience quickly puts an end to any concerns.
Never in my life did I think I would receive tennis lessons from Andy Murray's former coach, but his down-to-earth nature is quite relaxing. There's no intimidation in my lesson and I never feel like I'm being told off.
Mark spent two days training Neilson's LTA qualified tennis coaches earlier in 2016 and will consult with them regularly over the next two years, as they fine-tune a programme available to guests at the company's Greek and Turkish resorts.
"The ethos of any coaching is you want to make the person you're coaching the best that they can be," Mark tells me.
"Seeing somebody do something they thought was impossible beforehand – that's hugely satisfying for me."
Aware most holidaymakers will rarely spend longer than a week at resorts, Neilson's tennis coaches are focusing on the little things that can make a difference. Changing my grip, shifting my feet during a serve and opening the face of my racquet are all simple tips that I will take away with me when I return home to continue my practice.
Lessons are also loosely structured, so people can pick up where they left off if they skip a day to spend it at the beach instead. A daily programme of group coaching sessions will be available to guests at no extra cost. (Private coaching can also be booked from £32 per hour.)
"I want people to feel more confident about their game, so that when they go home, they feel as though they really understand what they're trying to do on the court," says Mark.
The approach is effective. I'm hardly likely to challenge Novak Djokovic any time soon, but my serve is now looking miles better. I've already progressed from the green (beginners) group, through to blue (casual players), and on to red (experienced), and eagerly await the tournament at the end of the week.
I wipe my brow before winding up for another serve. This time the ball clumps into the net. I'm getting tired, but Mark shows no signs of slowing down.
"Show me that grip. Open your face a little, let's have a nice C," he says, referring to my arm swing. Keeping the chat up is another key component of the training.
We move on to my forehand swing, where Mark wants me to loosen my grip and really try and whip the ball from down low to up high, and importantly, finish with the racquet over my shoulder and base pointing down court.
It takes a little while, but I finally get the knack.
Along with tennis lessons, guests at the Neilson resorts can sign up for a variety of sports and fitness activities.
I grew up near the sea, and it has been calling to me since I arrived, so the following morning, I make a beeline for the water skiing launch area. I've never tried the sport, but as a competent snow skier, I figure the skills are transferable, and my instructor assures me they are.
On our first outing, I find it easy to squat then gently rise out of the water as I hold onto a fixed training bar. But when I'm at the end of a rope, I start to struggle.
A few dumpings aside, I soon get used to holding my arms out straight and, as the water thumps my skis below, I hear a voice from the boat declare I'm "a natural".
Having made a splash, I return to land and join a 'beer and mountain bike ride' through some fields and a small village nearby. After a few sweaty kilometres, we pull up at a beach side bar.
Having burned more than a few calories in the past week, I feel deserving of a drink. Walking towards the bar, while practising a few serves, I reflect upon my improved tennis skills. I can't wait to challenge my friends to a game back home.
Right now, though, I have other priorities in mind. This is, after all, my holiday, and the only C swing I'll be making with my forearm is in the direction of a cool, reviving pint.
TRAVEL FACTS
:: Nick McAvaney was a guest of Neilson Holidays (www.neilson.co.uk; 0333 014 3350) who launched the Mark Petchey tennis programme this year across their Greek and Turkish Beachclubs. A seven-night stay at the Neilson Messini Beachclub costs from £535pp (saving £250pp), including accommodation in a club twin or double room, club board meal basis (daily breakfast and lunch plus four evening meals per week), a range of inclusive activities together with group tuition, plus free children's clubs for all ages (2-17yrs). Based on an October 2 departure.
