As Michael Jamieson, one of our most impressive sportspeople, all but announced his retirement from competitive swimming last week he admitted he could not have believed four years ago that it would have come to this.

The only member of the British swimming team to claim a silver medal at the London Olympics - none won gold - has been shocked by the precipitous nature of his own decline, to the extent that he failed to make the team for either last year’s World Championships or the forthcoming Games in Rio.

The 27-year-old suggested he had not been able to match previous results because the wear and tear on his body meant he could no longer push himself as mercilessly as he had in the build-up to the Olympics four years ago and felt that his less physically punishing regime did not suit him mentally.

“I was telling myself that the programme I’m doing now should suit me because I’m really fragile and this model is designed to protect you from that,” he said of the training he has been undertaking of late.

“However I look at it and the injuries I’ve had are because I’ve chosen to give it everything as long as I can, whereas when you go to a new model where you can do anything but it’s been hard to accept because I feel I work best in pushing it to the limit. I’m just not able to do that any more.”

In a curious twist of fate the result which prompted this typically open and honest discussion of the his state of mind - his fifth place finish in the 200 metres breaststroke at the British Swimming Championship - occurred just three days after it had been announced that England cricketer James Taylor had been forced to retire from that sport ridiculously prematurely and stunningly unexpectedly.

The 26-year-old had been diagnosed with arrhythmogenic right ventricular cardiomyopathy, a condition similar to that which ended the football career of Fabrice Muamba, the Bolton Wanderers player, at the age of 23 when he suffered a cardiac arrest during a match which stopped his heart for 78 minutes.

Thoughts consequently drifted back to a training incident which Jamieson sought to downplay at the time but at the very least coincided with the start of his decline, when his heart went into arrhythmia during training.

Jamieson light-heartedly suggested back then that he took some pride in what had happened because it showed he was pushing himself to his physical limits and beyond, but that in turn raises the question of what has to be done to protect some of these youngsters from themselves.

This happens at a time when a completely separate debate is taking place regarding the use of the drug meldonium by sportspeople from Eastern Europe in particular, which was placed on the banned list by the World Anti Doping Agency late last year.

The following has the danger of being misinterpreted as playing to the sort of defences offered by those dubious medical practitioners who claim that in doping athletes they are merely reinstating bodies to their ‘normal’ condition and neutralising the impact of the exertions to which they are subjected.

We rightly reject such reasoning as unacceptably unprincipled when discussing practices that we know involve abuse of substances which have the potential to be deeply harmful to those taking them simply to gain competitive advantage and the claims of Maria Sharapova and others that they were taking meldonium for medical reasons have duly been dismissed in that vein.

However from what evidence has been made publicly available it seems meldonium is designed to protect the heart, while there is as yet little in the way of definitive evidence that this particular pharmaceutical either enhances athletic performance or has the potential to do long term damage to those taking it.

That, in turn, invites the question of what it is that we object to in terms of doping.

If, for example, it is simply that taking a substance enhances performance then a cricketing chum has been at it for years with his standard pre-match ritual of two bottles of Miller without which he, at least, reckons he cannot bamboozle opposing batsmen with his wily ways. Alcohol is a drug which may well enhance performance by relaxing the user and there is no shortage of evidence of the long-term health implications.

If that is too frivolous, another of our number swears by taking anti-inflammatories before every match, over-use of which impacted sufficiently on the health of his fellow brisk medium pacer Ian Botham to contribute to his decision to quit the sport.

In making these observations if must be noted that no one has suggested that using meldonium could have done anything to protect Michael Jamieson, James Taylor or Fabrice Muamba. However the juxtaposition of these stories highlights the moral and ethical difficulties to be confronted in assessing what represents medical support of those prepared to push themselves beyond limits and what is doping.