Apparently getting into gear for his new arrival, the Duke of Sussex enjoyed watching a strenuous Jui-Jitsu display before serving lunch to youngsters at the charity initiative in Streatham.
Harry, whose wife Meghan is expecting their first child in late April, was visiting the John Corfield Centre, where volunteers and youth leaders run activities for kids aged seven to 16.
The 34-year-old was seen admiring the trampolining facilities before taking to the kitchen to help staff serve a hot, nutritious lunch of pasta and salad.
It was a rare lone appearance for Harry, who is more often than not inseparable from Meghan since they wed last May.
The seven months pregnant Duchess is currently enjoy a break in New York to see friends, who are said to be surprising her with a baby shower.
On her return she'll then join Harry on a trip to Morocco later this week, the first royal engagement in the North African country – where they'll highlight some of their key causes such as girls' education and empowerment for young people.
But today it was time for Harry to strike out on his own – and he seemed to be relishing his lunchtime visit with the Streatham Youth and Community Trust.
The Fit and Fed programme was launched in 2016 with the aim of offering children and young people free access to activity sessions and a nutritious lunch during school holidays.
Its objective is to increase young people's skills, help them build the confidence and to increase expectations of what they can achieve.