The UK Chief Medical Officer guidelines state that children aged 1-5 should participate in 180 minutes of movement each day and under 1's should have at least 30 minutes across the day of tummy time.
Infants (less than 1 year): Infants should be physically active several times every day in a variety of ways, including interactive floor-based activity, e.g. crawling.
For infants not yet mobile, this includes at least 30 minutes of tummy time spread throughout the day while awake (and other movements such as reaching and grasping, pushing and pulling themselves independently, or rolling over); more is better.
Tummy time may be unfamiliar to babies at first, but can be increased gradually, starting from a minute or two at a time, as the baby becomes used to it. Babies should not sleep on their tummies.
Toddlers (1-2 years): Toddlers should spend at least 180 minutes (3 hours) per day in a variety of physical activities at any intensity, including active and outdoor play, spread throughout the day; more is better.
Pre-schoolers (3-4 years): Pre-schoolers should spend at least 180 minutes (3 hours) per day in a variety of physical activities spread throughout the day, including active and outdoor play. More is better; the 180 minutes should include at least 60 minutes of moderate-to-vigorous physical activity.
91% of children aged 2-4 years are not meeting the Chief Medical Officer guidelines and therefore missing opportunities to develop the physical, mental, and emotional health benefits provided by physical activity.
The NHS website has guidelines on the amount of physical activity that children at different ages should be doing and suggests types of activities that are suitable.