THEY are the cult exercise regimes rigorously followed by fitness fanatics searching for the perfect body.

Millions of people are rapidly adopting high intensity fitness sessions to cram into their busy lives in the battle to beat the bulge.

But shocking figures from a Southampton expert reveals these “explosive exercises” have fuelled a four-fold increase in agonising injuries within three years.

Now a city expert warns that people pushing themselves to the limit in a quest for eternal youth are propelling themselves towards chronic diseases more common in elderly patients.

Gorav Datta, a surgeon at Southampton General Hospital, says he now sees 200 patients a year who are under 30 and suffering from hip and knee injuries and back problems, compared to around 50, just three years ago.

He is blaming this on the adoption of high-intensity workouts and “explosive” exercise programmes which people are juggling with their increasingly busy lives.

They include instructed fitness programmes and the adoption of indoor cycling among people of all levels of fitness and ability, he says.

He added: “Over the past few years there has been a real expansion in the fitness market designed to meet the needs of young people with many conflicting priorities to contend with.

“Cult fitness regimes and the use of over-zealous personal trainers, all of which emphasise high-intensity, high-impact work, appeal to those who want to cram exercise into their hectic daily lives.

“The problem, however, is that these short and intense bursts and repetitions can wreak havoc with joints and, longer-term, lead to the need for surgery.”

Some of the popular training regimes, which can be performed at gyms or at home, can consist of a range of repetitive aerobic exercises, body weight exercises, weightlifting and gymnastics which are performed in 30-minute to hour-long workouts.

He added: “I now see patients under 30 who have the types of bone and joint injuries we would previously have expected to see in people in their late 50s and 60s, with around a quarter requiring surgical intervention.”

He urged people to take-up more moderate workouts with adequate rest days, while people with established joint problems should and adopt low-impact exercises such as swimming and cycling and said: “The message for young people to avoid this predicament is to be careful not to over-train and to avoid some of the exercises and training regimes that can trash the joints.”

Oliver Tuson, an armed forces veteran who has set up his own fitness training company Oliver Tuson Personal Trainer (OTPT), said many young people taking up intense weightlifting regimes before their bodies are adequately prepared to take the loads, while others put their muscles and joints in danger by failing to warm up properly.

He said: “The health industry has grown and people are trying to copy what they see in glossy magazines. People should build up slowly and follow a structured regime from a professional who can assess their fitness.”