The agency has softened its stance as a parade of Scottish Executive ministers on Tuesday lent their backing to a revised - but strangely familiar - sports strategy for the next four years.
An insistence on two hours a week has been dropped in favour of a more aspirational commitment "to make progress towards" the target.
After reviewing its old four-year strategy, Sportscotland acknowledges "real practical obstacles to achieving this ambition by 2007, in terms of both the school estate and the numbers and training of teachers and coaches and other personnel who could make a contribution".
In a tacit acceptance that its target may be counter to the new realities in schools, Sportscotland states: "Schools are being encouraged to take a more flexible and innovative approach to curriculum design and delivery and so any move to prescribe a minimum time requirement is in conflict with this policy."
It accepts decisions on curriculum allocations will be left to headteachers, although it argues that the target should be retained "to keep the ambition firmly in view". Meanwhile the Scottish Executive is to gather baseline data on current PE provision over the next year.
Lindsay Roy, education convener of the Headteachers' Association of Scotland, said: "The practicalities present quite a challenge".
Mr Roy, head of Inverkeithing High in Fife, added: "It is about time for core subjects but it is also about the level of facilities across the country. If you have only one games hall, for example, you will find it difficult and some schools would need a considerable extension of facilities."
Kay Hall, president of the Association of Head Teachers in Scotland and head of West Kilbride primary in North Ayrshire, welcomed the subtle change. "Reality has to be part of the curriculum as well. We recognise we have an unfit generation but some of this has to be done outside school and properly funded. People should be paid for their commitment and we should not try to squash this into teachers' 25 hours."
In primaries, there was also a practical problem: gym halls are used for lunches.
Fitness and health continue to feature strongly in the Sportscotland strategy as the focus switches to more general activity outwith formal school hours. Picking up the recommendation of the Physical Activity Task Force, it backs the target of having primary children active for at least an hour a day on five days of the week.
HMI's review of primary PE 18 months ago suggested that relying on classes in physical education alone would not address concerns. It avoided any reference to time slots for PE.
A third Sportscotland target, again echoing the task force, is to widen opportunities for 13-17s, the group that experiences the sharpest decline in participation. Teenage girls remain the chief priority. Walking, cycling, dance and informal outdoor pursuits will be included in the get-them-active plan.