The figures emerge in a report on outdoor learning to be published this spring, based on analysis of nine secondary and eight primary schools all randomly chosen. The information was used at a conference in Dalkeith, where Chalmers Smith, outdoor learning co-ordinator for Midlothian Council, described it as "not wonderful".
He stressed, however, that where there was a willingness to take children outdoors, that tended to happen, despite limitations on time, transport, cost and support.
The research showed that in eight primary schools noted for their commitment to outdoor learning, it accounted for 68 minutes of a pupil's week - nearly four times as much as in the randomly chosen schools. In six secondary schools committed to outdoor learning, the figure was 39 minutes, or three times what it was in the random schools.
The research was conducted by Stirling University on behalf of Learning and Teaching Scotland and Scottish Natural Heritage.
Outdoor learning at Midlothian Council is delivered by a three-strong team at the Greenhall Centre in Gorebridge. It includes Eoin Keane, one of the first outdoor learning teachers recognised by the General Teaching Council for Scotland.