Children are less fit than they used to be, according to Toni Szifris, head of physical education at Portobello High, Edinburgh.
"We are encountering more and more kids who get frightened when their heart starts beating faster; they don't understand what's happening to them," he said.
He hopes to raise every pupil's heart rate next session when his department conducts fitness testing in response to the recommendations of the 5-14 initiative.
"We'll be introducing fitness profiles for each pupil so that they can find out more about their health and fitness as required in the 5-14 programme," said Mr Szifris, who is also involved in a pilot project to introduce more pupils to sport after school in the 4-6pm period. Napier University has provided sports coach students to help supervise the after-school activities for pupils in the first three years.
Mr Szifris commented: "By all means use the goodwill of teachers who want to help, but we must also use trained coaches. PE staff have long since taken their hands off the provision of extra-curricular sport in response to the demands of the curriculum."
As well as the traditional sports such as football, rugby and basketball, Portobello introduced classes for cheer-leaders and more than 40 of the 200 taking part in the after-school scheme wanted to do it: "The trendy things are popular. We presented it as a form of dancing and they enjoyed it. We even had requests for roller blading but that was not possible."
The evidence so far indicates a sharp drop-off in interest after second year. "By then you've probably lost the ground if you haven't got them in and they've filled up their time with other things, such as working after school," Mr Szifris said.
"Unless they're brought up in the habit of playing sport, it's probably a waste of time trying to get them back after first year but it's a rolling programme and we'll just have to see."
* Only one of 19 fourth-year Portobello pupils interviewed by the TESS was dissatified with their fitness level. Most said they played sport for several hours a week and added that they spent far more time playing sport than watching television.
* Twenty-three after-school football development centres have been set up in North Lanarkshire, attracting around 800 primary pupils. A joint councilScottish Football Association partnership has also helped 65 primaries to include football in the 5-14 curriculum.
* In East Lothian, more than half of the 32 primaries have after-school clubs in core sports. Twelve new junior sections in badminton, hockey and volleyball have been developed in sports centres.