It's a bit of a misleading headline which as it's the Guardian is to be expected.
This is the wording from the government that allows this:
Organised sport or exercises classes or licensed outdoor physical activity. This does not include informal sport or fitness activity with family or friends – this must be limited to a group of 6.
Elite sporting competition and training
So this covers all organized sports such as football, rugby, cricket as well as the licensed outdoor shooting events.