Pushy parents risk damaging their children's health if they link affection to sporting success, it has been claimed.
They face a 'delicate balance' between supporting playing field ambitions and pushing their children too far, a heads' conference was told.
Rod Jaques, national medical director of the English Institute of Sport, which works with elite athletes, said that in some case a parent's love can appear 'conditional' on the child achieving sporting success.
This can lead, he claimed, to youngsters developing eating disorders or inventing injuries.
Addressing the Headmasters' and Headmistresses' Conference (HMC), Dr Jaques said: 'I think it is a tough one when a parent comes into the consultation who is both the coach and parent. It is a potential for conflict of interest there.
'It's a very delicate balance between encouragement and support for that child, and its potential for being a mentor or a tormentor of the child I think is really quite real.
'It is often anecdotally said that behind every injured child is a parent athlete wanting to get out.
'Australians have gone a bit further and called this the ugly parent syndrome and we probably have witnessed this on the side of our rugby fields or football fields of the bawling parent, not just at the referee but at the child on the field of play.
'This love for their child should not be conditional on results and unfortunately it sometimes is.'
Speaking afterwards, Dr Jaques said most parents bringing up a child competing at a high level have the dynamic 'absolutely right' and are 'caring and loving and the love is entirely unconditional'.
But he added: 'Occasionally, I don't see that. The love is conditional upon them having sporting success. But that's rare, I want to stress that, it's rare, but it occasionally happens and it is worrying to see it in a medical context.
'In the worst case it can create eating disorders, it can make them invent injuries, or even protract injuries where we find no evidence of injury still existing but they still complain of pain.'
The conference also heard that private school pupils are more likely to become Olympic athletes than their state school counterparts.
Dr Jaques told delegates that 34 per cent of the Great Britain team at the Beijing games were educated privately, with almost half of Britain's medal haul won by privately educated athletes.
He later said private school pupils often have more sports to choose from, and better opportunities to train and succeed.
He said: 'For the state sector kid to make a success of their training they have to go an extra mile to do it.
'Mum and dad have to be that much more co-operative, mum and dad have to access sports clubs outside of the school setting and have the time and inclination to do that. It's a tough ask.'
Pushy Parents That Demand Results From Doctors
In one study, doctors looked back at 23 cases of children with unexplained severe abdominal pain referred to Great Ormond Street Hospital between 1997 and 2001.
They had all undergone checks, including blood tests, ultrasound and endoscopy.
Fifteen had already been seen by at least two consultants before they were seen at Great Ormond Street.
Two of the children had seen seven doctors prior to their referral.
Seven families had asked for extra tests to be carried out, even though there was no clinical indication they were necessary. Only two were successful, and in neither case did the results change the diagnosis.
Many parents had lost faith in the medical profession and were aggressive or confrontational with the GOSH doctor.
Twelve families made a formal complaint about the care their child received, hoping to persuade doctors into carrying out more investigations.
And, despite the link with psychological factors, only 13 families accepted referral to psychological services.
In 12, a high degree of family conflict or dysfunction had been seen, and parents were unaware of the potential impact this could have on their child's illness.
Eleven of these children improved after psychological support and resumed normal activities within a year.
Of the 10 families who refused psychological help, only three children eventually improved.
In each of these cases, the families accepted the role psychological factors played.