The gym is a joint initiative between Merton Youth Service and Merton Youth Inclusion and Support Panel, which have each provided 50,000 towards the running costs.
Jason Young, the Positive Activities for Young People youth worker running the programme, said: "The young people who are referred to the scheme are often engaged in antisocial behaviour, so we aim to channel their negative energies and use them in a positive way."
Emma Richards, manager of Merton Youth Offending Service, said: "The idea is to get young people interested in fitness and a healthy lifestyle. The programme is very gym-oriented and includes circuit training and other activities. This will then be combined with mentoring."
The programme will run twice a week from May to July and from September to December.
