title: The acute effect of exercise modality and nutrition manipulations on post-exercise resting energy expenditure and respiratory exchange ratio in women: a randomized trial.
abstract: BACKGROUND
  The purpose of this study was to examine the effect of exercise modality and pre-exercise carbohydrate (CHO) or protein (PRO) ingestion on post-exercise resting energy expenditure (REE) and respiratory exchange ratio (RER) in women.
  
  
  METHODS
  Twenty recreationally active women (mean ± SD; age 24.6 ± 3.9 years; height 164.4 ± 6.6 cm; weight 62.7 ± 6.6 kg) participated in this randomized, crossover, double-blind study. Each participant completed six exercise sessions, consisting of three exercise modalities: aerobic endurance exercise (AEE), high-intensity interval running (HIIT), and high-intensity resistance training (HIRT); and two acute nutritional interventions: CHO and PRO. Salivary samples were collected before each exercise session to determine estradiol-β-17 and before and after to quantify cortisol. Post-exercise REE and RER were analyzed via indirect calorimetry at the following: baseline, immediately post (IP), 30 minutes (30 min) post, and 60 minutes (60 min) post exercise. A mixed effects linear regression model, controlling for estradiol, was used to compare mean longitudinal changes in REE and RER.
  
  
  RESULTS
  On average, HIIT produced a greater REE than AEE and HIRT (p < 0.001) post exercise. Effects of AEE and HIRT were not significantly different for post-exercise REE (p = 0.1331). On average, HIIT produced lower RER compared to either AEE or HIRT after 30 min (p < 0.001 and p = 0.0169, respectively) and compared to AEE after 60 min (p = 0.0020). On average, pre-exercise PRO ingestion increased post-exercise REE (p = 0.0076) and decreased post-exercise RER (p < 0.0001) compared to pre-exercise CHO ingestion.
  
  
  CONCLUSIONS
  HIIT resulted in the largest increase in REE and largest reduction in RER.
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: Hailee L
authors.initials: HL
authors.lastname: Wingfield
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA. abbsmith@email.unc.edu.
authors.forename: Abbie E
authors.initials: AE
authors.lastname: Smith-Ryan
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: Malia N
authors.initials: MN
authors.lastname: Melvin
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: Erica J
authors.initials: EJ
authors.lastname: Roelofs
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Trexler
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.|Department of Nutrition - Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Hackney
authors.affiliation: Departments of Medicine and Biostatistics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Weaver
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina, 209 Fetzer Hall, CB #8700, Chapel Hill, NC, 27599-8700, USA.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Ryan