Many lives are led at speeds faster than drinkers’ digits tweeting snaps of their schnapps. Unable to function at anything less than an eyeballs-out pace, the pursuit of fitness is no less frenzied, and it’s a widespread assumption that in order for bodily improvement to occur during the brief timeframe allocated to exercise, one’s energy expenditure must exceed that needed to power up, say, a Bessemer converter.

This approach might explain the condition called exertional rhabdomyolysis (ER), increasingly prevalent – but not exclusively so – among exercise-naive attendees of spinning classes.

A spinning class involves mounting a stationary bike and pedalling furiously. For some participants this means summoning their out-of-condition musculature into an effort it’s ill-prepared for. ER develops following damage to striated muscle cell membranes, the injury flooding the circulation with minerals, enzymes and other proteins.

The presence of excess calcium triggers further muscle necrosis, and acute renal failure may occur.

Last year, in the Ulster Medical Journal, clinicians at Daisy Hill Hospital, Newry, reported two cases of ER.

The first was in a 21-year-old woman who was hospitalised two days after a 40-minute spin class, her first return to strenuous exercise after giving birth four months previously.

She had swollen, stiff and painful legs, plus increased thirst. She underwent “intravenous fluid resuscitation” and was discharged two days later.

In the second case, a previously healthy 17-year-old female was hospitalised with painful and tender legs the day after her first spin class, lasting 45 minutes.

Prevention

The Newry clinicians suggest the condition can be avoided by performing “sub-maximal training over a longer period of time instead of short bursts of high intensity and limited exercise in hot conditions”, plus staying hydrated, ensuring a high carbohydrate intake and spacing out rest periods “to optimise glycogen repletion”.

In the Current Sports Medicine Reports journal last year, Dr Randy Eichner said the first case of so-called "spinning rhabdo" he located in the medical literature was reported in 2003, describing a 49-year-old man who was hospitalised after his first one-hour spinning class.

In the January/February 2016 issue of the same journal, Eichner cites the case of a 25-year-old woman who described the experience of her first spinning class, when she was “encouraged to go all out”, an exhortation which resulted in a six-day hospitalisation.

The woman was given a refund, although the gym owner – plus his lawyer – said they had never heard of ER and that it couldn’t be caused by spinning.

This means that the gym owner – plus his lawyer – had failed to note three warnings published in 2005 and 2006 by spinning.com in which instructors were warned about the risk of ER for novice spinners.

According to Eichner, there are at least 50 recorded cases of “spinning rhabdo” in the medical literature to date.

Intense pain

ER, however, is not restricted to those who do spinning classes, as a report in the

Clinical Journal of Sports Medicine

(2013, 23: 496) underlines; also highlighting the fact that an in-depth knowledge of ER confers no immunity against the condition.

In Exertional Rhabdomyolysis in an Acutely Detrained Athlete/Exercise Physiology Professor we learn how an ER expert did 400 press-ups and 200 pull-ups in 48 minutes; experienced some difficulty moving his arms and upper body; played ice hockey the next day, despite intense pain; and ended up in hospital, during which time, one assumes, his professorial intellect may have reflected on what seems to be a craze for frenzied activity.

In her book Wanderlust: a History of Walking, Rebecca Solnit suggests that both mind and feet work well together at about three miles an hour. "If this is so," she writes, "then modern life is moving faster than the speed of thought, or thoughtfulness."

The search for fitness has become a box-ticking exercise, with frantic pedalling, bench-pressing or weekend sprints around muddy obstacle courses squeezed into schedules tighter than a pair of Spandex breeks.

Medics and organisers have a responsibility to point out that participation in a mass-athletic event does not necessarily confer the status of athlete on ill-prepared participants.

But in this era of entitlement, when we are all encouraged in the belief that we can be anything we want to be, who dares to suggest that Solnit’s advice to spend some time encouraging mind and feet to work together at about three miles an hour is more sensible than coaxing individuals to cram some all-out action into a rigid time slot?

The acquisition of fitness often depends more on the philosophy of a tortoise than a hare.