140 employees of an automobile company (11 % female, median age 48 years (range 25–60), BMI 29.0 kg/m2 (25.0–34.8)) were randomized in a 3:2 ratio to an intervention group receiving structured exercise schedules or a control group choosing workouts individually via an interactive website. The 12-week intervention took place in Munich, Germany, during summer 2008. Main outcome measure was performance at the lactate anaerobic threshold (PAT/kg) during ergometry.
77 participants completed the study. The intervention group (n = 50) improved significantly in PAT/kg ((mean (SD)) 1.68 (0.31) vs. 1.81 (0.33) W/kg; p = 0.002), VO2peak (3.21 (0.63) vs. 3.35 (0.74) L/min; p = 0.04), and waist circumference (100.5 (7.9) vs. 98.0 (7.8) cm; p = 0.001). The control group (n = 27) improved significantly in PAT/kg (1.59 (0.38) vs. 1.80 (0.49); p < 0.001) and waist circumference (101.9 (8.7) vs. 98.3 (8.5) cm; p < 0.001), but not in VO2peak. No significant between group differences in these outcome measures were noted.
Structured, internet-delivered exercise recommendations are not superior to internet-delivered non-structured exercise recommendations in a workplace setting. Both lifestyle intervention strategies are, however, limited by high dropout rates.