The Prime Minister told a Downing Street press conference on Monday he was “thrilled” by the prospect of being able to play tennis again as outdoor sports events resume.
It comes as Sir Keir told reporters earlier in the day that he was looking forward to being able to “shout and scream” on the football pitch once again.
Stressing the benefits of exercise to build the UK’s “resilience” to Covid-19, Mr Johnson said: “I am personally thrilled that I will be able to play tennis, for instance.
“Without being remotely preachy, I do hope that we can take advantage of this moment and the beautiful weather to play sport, to take exercise, to have fun and build our national resilience in that way too.”
Football and cricket pitches, tennis and basketball courts, outdoor swimming pools, golf courses and sailing clubs are now free to reopen after months of being shuttered.
Organised team sports can also resume outdoors, meaning grassroots competitions can take place ahead of the Easter break without the need for social distancing.
Sir Keir said he was planning to play football on Monday evening after months of being unable to do so under lockdown.
He said: “I’m very much looking forward, this evening, to playing my first game of five-a-side for some time.
“So I will be out there, on the pitch, enjoying the fact that today I can shout and scream and go around the football pitch and have that game of five-a-side.”