No previous studies have investigated a high-intensity interval training program (HIIT) with an immersed ergocycle and Mediterranean diet counseling (Med) in obese patients. We aimed to compare the effects of an intensive lifestyle intervention, Med and HIIT with a water-immersed versus dryland ergocycle, on cardiometabolic and exercise parameters in obese patients.

We retrospectively identified 95 obese patients at their entry into a 9-month Med and HIIT program: 21 were trained on a water-immersed ergocycle and 74 on a standard dryland ergocycle. Body composition, cardiometabolic and exercise parameters were measured before and after the program.

For obese patients performing water- and dryland-exercise (mean age 58±9 years versus 55±7 years), BMI was higher for the water- than dryland-exercise group (39.4±8.3kg/m² versus 34.7±5.1kg/m², P<0.05), and total fat mass, fasting glycemia and triglycerides level were higher (P<0.05). Both groups showed similarly improved body composition variables (body mass, waist circumference, fat mass, P<0.001), fasting glycemia and triglycerides level (P<0.05). Initial maximal aerobic capacity (metabolic equivalents [METs]) and maximal heart rate (HR_max) were lower for the water- than dryland-exercise group (P<0.05). For both groups, METs, resting HR, resting blood pressure, abdominal and leg muscle endurance were similarly improved (P<0.05).

A long-term Mediterranean diet and HIIT program with water-cycling is as effective as a dryland program in improving body composition, fasting glucose, triglycerides level, blood pressure and fitness in obese patients. A Mediterranean diet combined with water-cycling HIIT may be efficient for severely obese patients at high risk of musculoskeletal conditions.