The Roosevelt Island Operating Corp (RIOC) installed several pieces of exercise equipment at an outdoor fitness area between the West Promenade and Octagon Soccer Field.
Have you tried it yet? The fitness area can accommodate all exercise skill levels from this man doing

Image From Goldenarms 921 You Tube Video Muscle Ups , a combination of Pull Ups and Dips,
to less strenuous activities on an eliptical machine, balance beam

chest press

and more.
Give it a try. At one time, RIOC had discussed placing an outdoor exercise equipment area in Soutown as well but that never happened.
