1370-P: Effects of Concomitant High-Intensity Interval Training or Resistance Exercise Training on Muscle Protein Synthesis, Body Composition, and Metabolic Markers following 6-Week VLCD among Healthy Overweight/Obese Men

Background: Very Low-Calorie Diet (VLCD) is effective for rapid weight loss but is associated with lean mass (LM) loss. Resistance exercise training (RET) and high-intensity interval training (HIIT) are known to promote muscle hypertrophy or improvements in cardiopulmonary fitness (CPF) . We therefore explored the effects of VLCD with or without RET or HIIT on body composition, metabolic markers, and CPF. Methods: Participants were randomly allocated into VCLD only (n=10; 46±8y; 104±12kg; BMI 32±4, mean±SD) , VLCD+RET (n= 8; 40±8y;99k±10kg; BMI 32±2) or VLCD+HIIT (n=8; 46±11y; 101±12kg; BMI 33±3) . All groups had six weeks of VLCD. Exercise groups had supervised training three times/week. Pre- and post-interventions assessment included DXA scan, lipid profiles, insulin sensitivities, blood pressure, cardiopulmonary exercise test and biopsy of vastus lateralis muscle for muscle protein synthesis (MPS) using deuterium oxide technique. Results: Significant reduction in body weight (-11.1±3 kg, -10.8±4kg, -11.7±4kg) , fat mass (-6.8±2kg, -6.9±2kg, -7.7±3kg, and LM (-4.3±2kg, -3.9±2kg, -4±1kg) were seen for VLCD only, VLCD+RET and VLCD+HIIT respectively (P<0.0001) , with no between-groups difference. MPS rate following interventions were 0.8%±0.2d-1, 0.9%±0.2d-1 and 1.2%±0.2d-1 (statistically higher in VLCD+HIIT compared to VLCD only; P=0.004) . Significant improvements were seen in metabolic markers (insulin sensitivities, lipid profiles and blood pressure) in all groups, with no inter-group difference. No intra- and inter-groups differences were seen for VO2max or anaerobic threshold. Conclusion: VLCD with or without exercise induced marked weight loss, improved insulin sensitivities, and metabolic markers despite LM loss. HIIT was associated with significant improvement in MPS and may be used as an adjunct to preserve VLCD induced LM loss. Disclosure M.Abdul aziz: None. I.Ramzan: None. N.Gharahdaghi: None. M.Brook: None. D.J.Wilkinson: None. B.E.Phillips: None. K.Smith: None. P.J.Atherton: None. I.R.Idris: None.