The grades used are:
Easy: Generally flat trails with a smooth surface and some gentle slopes or shallow steps. These trails are generally suitable for family groups including children and the elderly. Normal outdoor footwear can be worn.
Moderate: These trails may have some climbs and may have an uneven surface where the going is rough underfoot with some obstacles such as protruding roots, rocks, etc. The routes are appropriate for people with a moderate level of fitness and some walking experience. Specific outdoor walking footwear and clothing is recommended.
Strenuous: These are physically demanding trails, which will typically have some sections with steep climbs for long periods and the going underfoot can be extremely rough including many obstacles. Suitable for users accustomed to walking on rough ground and with a high level of fitness. Specific outdoor walking footwear and clothing required.