BackgroundThe aim of this study was to compare carbohydrate and lipid oxidation during moderate intensity continuous exercise (MICE) and high intensity intermittent exercise (HIIE) in patients with chronic heart failure (CHF).MethodsEighteen males with CHF (60±9 years, LVEF = 26±7%, VO2peak = 17.4±5.5 mL/min/kg) were assigned in random order to a single session of high-intensity interval exercise corresponding to 2×8 min of 30s intervals at 100% of peak power output (PPO) and 30s passive recovery intervals and one week later to a 22 min isocaloric MICE corresponding to 60% of PPO. Gas exchange, ECG and blood pressure were monitored continuously. VO2 uptake and energy expenditure were assessed from gas exchanges and carbohydrate and lipid oxidation using the Frayn equation. Endpoints were carbohydrate and lipid oxidation measured during the last 2 minutes of HIIE blocs and corresponding same exercise time period on MICE.ResultsVO2 uptake and energy expenditure during exercise did not differ (P=0.10) between MICE (VO2=1208 and 1263±289 and 311 mL/min, EE=6.08 and 6.29±1.45 and 1.53 kcal/min) and HIIE (VO2=1048 and 1074±239 and 238 mL/min, EE=5.26 and 5.37±1.21 and 1.28 kcal/min). Carbohydrate (CHO) and lipid oxidation during exercise were similar (P=0.09 and 0.63) between MICE (CHO=1.66 and 1.46±0.48 and 0.37 g/min, lipids=0.05 and 0.10±0.06 and 0.09 g/min) and HIIE (CHO=1.39 and 1.20±0.45 and 0.39 g/min, lipids=0.06 and 0.11±0.05 and 0.06 g/min) in CHF patients.ConclusionThese findings showed that carbohydrate and lipid oxidation during exercise are similar between 2 isoenergetic exercise bouts of different form and intensities in CHF patients.EPIC Foundation, MHIF BackgroundThe aim of this study was to compare carbohydrate and lipid oxidation during moderate intensity continuous exercise (MICE) and high intensity intermittent exercise (HIIE) in patients with chronic heart failure (CHF). The aim of this study was to compare carbohydrate and lipid oxidation during moderate intensity continuous exercise (MICE) and high intensity intermittent exercise (HIIE) in patients with chronic heart failure (CHF). MethodsEighteen males with CHF (60±9 years, LVEF = 26±7%, VO2peak = 17.4±5.5 mL/min/kg) were assigned in random order to a single session of high-intensity interval exercise corresponding to 2×8 min of 30s intervals at 100% of peak power output (PPO) and 30s passive recovery intervals and one week later to a 22 min isocaloric MICE corresponding to 60% of PPO. Gas exchange, ECG and blood pressure were monitored continuously. VO2 uptake and energy expenditure were assessed from gas exchanges and carbohydrate and lipid oxidation using the Frayn equation. Endpoints were carbohydrate and lipid oxidation measured during the last 2 minutes of HIIE blocs and corresponding same exercise time period on MICE. Eighteen males with CHF (60±9 years, LVEF = 26±7%, VO2peak = 17.4±5.5 mL/min/kg) were assigned in random order to a single session of high-intensity interval exercise corresponding to 2×8 min of 30s intervals at 100% of peak power output (PPO) and 30s passive recovery intervals and one week later to a 22 min isocaloric MICE corresponding to 60% of PPO. Gas exchange, ECG and blood pressure were monitored continuously. VO2 uptake and energy expenditure were assessed from gas exchanges and carbohydrate and lipid oxidation using the Frayn equation. Endpoints were carbohydrate and lipid oxidation measured during the last 2 minutes of HIIE blocs and corresponding same exercise time period on MICE. ResultsVO2 uptake and energy expenditure during exercise did not differ (P=0.10) between MICE (VO2=1208 and 1263±289 and 311 mL/min, EE=6.08 and 6.29±1.45 and 1.53 kcal/min) and HIIE (VO2=1048 and 1074±239 and 238 mL/min, EE=5.26 and 5.37±1.21 and 1.28 kcal/min). Carbohydrate (CHO) and lipid oxidation during exercise were similar (P=0.09 and 0.63) between MICE (CHO=1.66 and 1.46±0.48 and 0.37 g/min, lipids=0.05 and 0.10±0.06 and 0.09 g/min) and HIIE (CHO=1.39 and 1.20±0.45 and 0.39 g/min, lipids=0.06 and 0.11±0.05 and 0.06 g/min) in CHF patients. VO2 uptake and energy expenditure during exercise did not differ (P=0.10) between MICE (VO2=1208 and 1263±289 and 311 mL/min, EE=6.08 and 6.29±1.45 and 1.53 kcal/min) and HIIE (VO2=1048 and 1074±239 and 238 mL/min, EE=5.26 and 5.37±1.21 and 1.28 kcal/min). Carbohydrate (CHO) and lipid oxidation during exercise were similar (P=0.09 and 0.63) between MICE (CHO=1.66 and 1.46±0.48 and 0.37 g/min, lipids=0.05 and 0.10±0.06 and 0.09 g/min) and HIIE (CHO=1.39 and 1.20±0.45 and 0.39 g/min, lipids=0.06 and 0.11±0.05 and 0.06 g/min) in CHF patients. ConclusionThese findings showed that carbohydrate and lipid oxidation during exercise are similar between 2 isoenergetic exercise bouts of different form and intensities in CHF patients.EPIC Foundation, MHIF These findings showed that carbohydrate and lipid oxidation during exercise are similar between 2 isoenergetic exercise bouts of different form and intensities in CHF patients.