"Ian, your left side is totally shaking. Try and centre yourself. Run with perfect balance."
If anyone knows about perfectly balanced running, it's Kennedy Ochieng. Twice Olympic 400m bronze medallist, twice African champion, he's more used to competing against Michael Johnson than a wheezing, lopsided amateur, whose career pinnacle was reached in the Bedford half-marathon. In 1987.
No contest perhaps. But my brush with athletics' elite - a half-hour jog past lush vegetation, piles of elephant dung and screaming monkeys in Kenya's Arabuko-Sokoke forest - was just one more exhilarating experience at Wild Fitness: a lung-pumping fusion of adventure holiday and fresh air workout.
Centred on the Indian Ocean coastline south of Malindi, the course takes exercise out of the gym and into the wilderness: towering sand dunes, bleached white beaches and mangrove swamps, as well as the fish-infested reef of Watamu Marine Park.
"We're concerned with primary fitness," said Steve Bacot, a 34-year-old fitness instructor and ex-para. "We're working on the agility, co-ordination, balance, strength and speed you see in animals. This is about adventure, survival and getting fit while you're having fun. Forget developing a rippling six pack." I did - 25 years ago.
The evidence that this would be no ordinary tropical holiday was there before we left Britain. A questionnaire checked our health, diet, boozing habits and whether we had an irrational fear of wildlife (no, my fear of charging six-ton elephants is entirely rational). A disclaimer used words like "demanding" and "tiring"; however, "margarita", "tan" or "sun lounger" did not appear.
Within an hour of arriving we'd had a post-flight massage and were into the first exercise session on the rooftop of Baraka, the Moorish-style home that would be our base for the week. As the equatorial sun dropped below the horizon, we attempted to balance on wobble boards and stretch around large, inflated Swiss balls.
It might look like a Women's Institute activity class circa 1928 - next up, Margery's knitting tips - but it is actually working on core stability; recruiting and honing the deep abdominal muscles that support the spine. For someone whose middle region has the stability of the San Andreas Fault, it promised to be an interesting week.
Class over, we supped ice cold mango juice and slurped fresh oysters as bats swooped overhead - something that's never happened after a run in Tooting - before an uber-healthy supper of coconut soup and grilled white snapper. It set the tone for one of the most nutritious weeks of my life.
We needed the energy. We'd risen at 6.30am for a swim session in a gloriously warm Indian Ocean, and would later attend lectures on functional fitness, learning movements applicable to everyday life, as well as a more detailed peek at nutrition.
There was also a 90-minute massage and meditation - it turned me into grinning, speechless putty. I'd anticipated gaining flexibility and strength at Wild Fitness, but not expected to find a river of golden light flowing into my head and out of my toes. It was all very Glastonbury.
And that wasn't the end of it. The day also contained a posture assessment, circuit training, fitness test and Ashtanga yoga, the regime that re-shaped Geri Haliwell. But not me. For one thing I don't possess a micro bikini, for another there were no paparazzi around to let me flaunt my backward crab.
It wasn't until day three, however, that Wild Fitness really started to live up to its name. We drove out to Sita Village where our warm up stretches provoked screams of laughter from locals, who then followed us down to a narrow muddy channel overgrown with mangroves. It was the launch pad for a vigorous burst of activity: a two-and-a-half-mile swim. Six villagers accompanied us in hollowed-out canoes as we headed, aided by a strong current, down the middle of an ever-widening creek towards the Indian Ocean.
After an hour, we hit a long sandbank in mid-stream (it was over half a mile wide by now) where I was approached by an inquisitive stranger, dry from the waist up. He was wading through the thigh-deep water and was clearly a fan of the BBC World Service.
"Hello, I'm Military," he said. "Who are you?"
"Hello Military," I replied. "I'm Ian."
"Aah, Iain Duncan Smith."
"Not if I can help it."
An hour later, without anyone else mistaking me for a political leader, we arrived at our destination and a tasty chicken curry. It was necessary re-fuelling - we had another hour's hike along the beach past wheeling fish eagles, before more gruelling endurance training.
It's no surprise to find time flies at Baraka. Day four, 6.30am? It must be boxercise. My heart rate - we were constantly monitored - hit 148, but I think it was just the excitement of reaching breakfast alive. It was followed by a more intensive look at the acronym hell that is core stability. We had to work on our TVA (transversus abdominis), IO (internal obliques) and TLF (thoraco-lumbar facia). Frankly, I was just keen to loose some LARD (lard) off my BELLY (belly).
There were several other forays into the local environment over the week, including an African lunch, a flora and fauna walk, a visit to 12th century Swahili ruins and snorkelling over the reef. The afternoon of day four also involved more training circuits with exercises and weights, before a sunset run through the village of Dongo Kundu, past shallow swamps and thick forest. When we hit an open plain, our sprint training attracted a crocodile of squealing children following behind. And it wasn't over yet. At the end of the day, we had a beach barbecue, followed by tribal dancing; a bit like the hokey cokey on amphetamines.
Either we were getting fitter, or the instructors were being kinder, but the days seemed to be getting easier. There was a less taxing yoga session - although I still had the flexibility of a Thatcherite economist - and a float down an inlet of Mida Creek; hiking and swimming upstream before using the current to float back. Of course, we still squeezed in a killer circuit, before running with the famous Kennedy Ochieng.
It may have been demanding, but it was, by group consensus, one of the best holidays of peoples' lives. On the penultimate day, five out of the six-strong group (maximum size eight) swapped their only lie-in for 6.30am boxercise.
Our reward was a day on the elegy-inducing curve of beach at Cha Chale, 70s haunt of Hollywood glitterati like Liz Taylor, Richard Burton and Woody Allen. Of course we couldn't just lie on the sand flecked with gold Mica flakes and black titanium. As well as a swim across the bay, we greeted the sunset with a sprint up and down an increasingly epic series of dunes. By the end we were coated with a layer of sweat and sand, our faces glowing in the warm, honey light of early evening.
That just left a last day's marlin fishing. Our boat had seen its fair share of physical activity. "It used to be owned by Lady Delamere of White Mischief fame," said Gary Cullen, the MD of Hemmingway's, who chartered the boat. "When we bought it, all there was on board was a cocktail bar and double bed."
After one final circuit, we left with bespoke stretching and exercise routines. Exhausted but inspired. Two weeks' Wild Fitness would jump-start the most slothful couch potato; six would be a major boost for anybody's body and mind. Somehow, the gym has never had quite the same appeal again.
Way to go
Wild Fitness: call 0207 368 1632, or visit the website at www.wildfitness.com.
A nine-day "kick-start" course costs £1,600, a two-week "tool-box" course costs £1,995 and a six-week "immersion" course £5,500.
Flights, insurance, and certain activities such as kite surfing, scuba diving, and deep sea fishing are extra.
Fly with Kenya Airways (01784 888222). Return flights to Malindi via Nairobi cost from £547, including tax.
Deep sea fishing at Hemingway's costs $220 for half a day. Contact Outposts on 01647 231007.
