High Fiber Diet & HIITThe Effect of a High Fiber Diet and High-Intensity Interval Exercise in Patients With HFpEF

Enrolled patients will perform supervised exercise on 3 nonconsecutive days of the week for 4 weeks.

Enrolled patients will have all of their food prepared for them by a registered dietician for the duration of the study period. The diet will consist of a high fiber content DASH diet.

Enrolled subjects will undergo both the exercise training visits and be provided with the DASH diet.

Patients will be required to report for three sessions of supervised stationary cycling exercise per week over a period of 4-weeks. Training heart rates will be determined based on the pre-testing VO2peak and peak heart rate (PHR). All sessions will be supervised by trained personnel.

Patients will start with eight intervals of 2-min duration at 80-85% of PHR, separated by 2 min of recovery at 50% of PHR, progressing to four, 4-min intervals at 90-95% PHR, separated by 3 min at 50% PHR by the end of week 2.

Each training session will begin with a 10-min warm-up at 50% of PHR and end with a 5-min cool down at 50% PHR. Subjects will be weighed prior to every exercise session and weight tracked to ensure that their volume status hasn't changed significantly. Subjects will be instructed to maintain usual levels of physical activity and usual diet during the study and not to make any modifications to the same.

Patients will be interviewed with regard to their food/religious preferences and food allergies and a 7-day rotating meal plan will be designed per their preferences along with a registered dietitian. This will ensure that patients receive food that is acceptable to them. Participants will then be provided pre-packaged meals for 4-weeks with macronutrient compositions as follows - (Carbohydrates -55-60%, Protein -15-20%, Fat -15-25%, Fiber -35-45g/day). All foods will be labeled, sealed, and packed for weekly delivery and will be designed such that they can be refrigerated or frozen and stored without significant alterations to nutritional content. All food will be prepared by the UVA Hospital Nutrition Services department in conjunction with a registered dietician. Deviations (if any) from the study meal plan will be recorded by the participants in a food record provided at the start of each diet intervention period.

Patients will undergo both the exercise training intervention and DASH diet as explained above.