A modular exercise system comprising: a first support frame module having a first support frame comprising a plurality of frame member: comprising a pair of upright frame members (14a,14b) defining opposing lateral sides of the first support frame module, each frame member being joined to an adjacent frame member of the first support frame module and oriented in a common plane such that the first support frame is two-dimensional in form; a weight source mounted on the first support frame; a plurality of pulleys mounted to different frame members of the first support frame; and a cable running from the weight source over the pulleys to connect the weight source to one or more manual actuator for performing a resistance exercise in use, the weight source and pulleys being located between the upright frame members; characterised in that the first support frame comprises one or more attachment formation for selective attachment to one or more further support frame module; a further support frame module also having a further support frame comprising a plurality of frame members being two-dimensional in form and selectively attachable in a side-by-side arrangement to the attachment formation of the first support frame in an orientation within the common plane such that the entire exercise system including the first and further support frame modules (10,100) has a depth dimension of less than 200mm, wherein the further support frame module comprises one or more further manual actuator wherein either or both of the upright frame members (14a,14b) of the first support frame module comprise one or more cable opening to allow the cable to pass through said upright frame member (14a,14b) from the first to the further support frame module: wherein the cable comprises a plurality of connector locations for attachment of one or more manual actuator within the first support frame module, such that the first support frame module is configurable as exercise equipment in its own right, offering a plurality manual actuator configurations based on the cable and pulley wheels within the first support frame module alone and the further support frame module is selectively useable to offer one or more further exercise option for the user. a first support frame module having a first support frame comprising a plurality of frame member: comprising a pair of upright frame members (14a,14b) defining opposing lateral sides of the first support frame module, each frame member being joined to an adjacent frame member of the first support frame module and oriented in a common plane such that the first support frame is two-dimensional in form; a weight source mounted on the first support frame; a plurality of pulleys mounted to different frame members of the first support frame; and a cable running from the weight source over the pulleys to connect the weight source to one or more manual actuator for performing a resistance exercise in use, the weight source and pulleys being located between the upright frame members; characterised in that the first support frame comprises one or more attachment formation for selective attachment to one or more further support frame module; a further support frame module also having a further support frame comprising a plurality of frame members being two-dimensional in form and selectively attachable in a side-by-side arrangement to the attachment formation of the first support frame in an orientation within the common plane such that the entire exercise system including the first and further support frame modules (10,100) has a depth dimension of less than 200mm, wherein the further support frame module comprises one or more further manual actuator wherein either or both of the upright frame members (14a,14b) of the first support frame module comprise one or more cable opening to allow the cable to pass through said upright frame member (14a,14b) from the first to the further support frame module: wherein the cable comprises a plurality of connector locations for attachment of one or more manual actuator within the first support frame module, such that the first support frame module is configurable as exercise equipment in its own right, offering a plurality manual actuator configurations based on the cable and pulley wheels within the first support frame module alone and the further support frame module is selectively useable to offer one or more further exercise option for the user.