To the best of our knowledge, no previous study has examined the health-promoting effects of a daily supervised concurrent workplace training program in inactive office workers. The main objective of this study was to examine the effectiveness of a 6-month workplace training program on health indices, musculoskeletal pains, functional capacity, and physical fitness in office workers. Randomized controlled study. Four workplaces in the Region of Thessaly, Greece. A total of 36 office workers (≥6 hours/d, 5 days/wk) were randomly assigned to either a training group (TG; n = 18) or a control group (CG; n = 18). The TG participated, every working day, in a 6-month supervised concurrent (flexibility, strength, balance, aerobic) training program (120 training sessions, 2 workouts/d of 15-20 minutes) that was implemented, in small groups, at the workplace during the work shift. The CG did not participate in any training. Health indices (body composition, blood pressure, respiratory function), musculoskeletal pains, functional capacity (flexibility, balance), and physical fitness (maximal strength, cardiorespiratory fitness) were measured before and after the completion of the program. After the completion of the program, participants' enjoyment was assessed. Two-way analysis of variance (group × time) with repeated measures on the "time" factor. The statistical power, for all parameters, ranged from 0.85 to 0.94. Training group significantly increased lean body mass (3.81%); respiratory function (4.20%-4.53%); cervical, handgrip, back, and leg maximal strength (8.75%-26.55%); and functional capacity (19.71%-188.20%; P < .001-.01; Cohen's effect size: 0.80-7.21), while significant reductions were observed on body fat (7.58%), blood pressure (4.99%-8.05%), heart rate (12.80%), and musculoskeletal pains (33.33%-100%; P < .001; Cohen's effect size: 0.81-6.21). In CG, all the above variables did not change. Furthermore, a great percentage of workers (94.4%) reported high levels of enjoyment. The program "HealPWorkers" is an enjoyable exercise modality that may be safely and effectively used, to work settings, for the improvement of worker's health, overall fitness, and functional capacity.