Effects of Steady State and High-Intensity Exercise on Compensatory Eating Behavior Study Notes

Study Overview and Objectives

• Research Title: Effects of Steady State and High-Intensity Exercise on Compensatory Eating Behavior.

• Authors: Emily Sauers, Johnathan P. Klein, Chad A. Witmer, Gavin L. Moir, Shala E. Davis (East Stroudsburg University of Pennsylvania, East Stroudsburg, PA).

• Primary Aim: To observe differences in compensatory eating behaviors and macronutrient selection following High-Intensity Intermittent (HI) exercise versus Vigorous Intensity Steady State (SS) exercise.

• Context: While exercise is critical for weight management, results are often individualistic. One potential reason for lack of weight loss is compensatory eating (eating more after exercise to offset caloric expenditure).

• Hormonal Background: Acute and chronic exercise can influence appetite by increasing anorexigenic hormones such as cholecystokinin ($\text{CCK}$), polypeptide YY ($\text{PYY}$), and glucagon-like peptide-1 ($\text{GLP-1}$), while decreasing appetite-stimulating hormones like acylated ghrelin ($\text{AG}$) in the gastrointestinal tract.

• Key Words: Caloric expenditure, macronutrients, eating behaviors.

Scientific Methodology

Participant Demographics

• Sample Size: $9$ individuals ($3$ males and $6$ females) from the East Stroudsburg University community.

• Age: $23.6 \pm 1.3$ years old.

• Fitness Level: Recreationally active with a $\text{VO}_2\text{max}$ of $47.0 \pm 2.9\,\text{ml/kg/min}$.

• Body Composition: Non-obese; weight stable for the previous $6$ months.

  • Height: $66 \pm 1\,\text{in}$.

  • Weight: $148 \pm 7\,\text{lb}$.

  • Body Mass Index (BMI): $24 \pm 0.7\,\text{kg/m}^2$.

  • Body Fat Percentage: $20 \pm 2\%$.

• Inclusion Criteria: Non-smokers, not taking dietary supplements, free of cardiovascular, metabolic, and renal disease.

Preliminary Assessments

• Screening: Subjects completed a written informed consent, a Physical Activity Readiness Questionnaire ($\text{PAR-Q}$), and a weight/activity history.

• Equipment:

  • Height/Weight: Wall-mounted stadiometer and Detecto physician’s scale.

  • Body Composition: Air-displacement plethysmography via $\text{BOD POD}^{\circledR}$ (COSMED, Concord, CA).

  • Exercise Testing: $\text{Quinton}^{\circledR}\text{ TM55}$ motorized treadmill using the Bruce protocol.

  • Gaseous Analysis: $\text{Parvo Medics TrueOne 2400}$ metabolic cart.

  • Heart Rate Monitoring: $\text{Polar T-31}$ heart rate monitor.

• $\text{VO}_2\text{max}$ Validation Criteria:

  1. $\text{VO}_2$ increase < 50\,\text{ml/min} with increasing workload.

  2. Rate of Perceived Exertion ($\text{RPE}$) $\ge 17$ on the Borg Scale.

  3. Heart Rate ($\text{HR}$) > 85\% of age-predicted maximum.

Exercise Protocol Design

Trial Structure

• Subjects were blinded to the study's true purpose (told it was a heart rate response study) to prevent biased food selection.

• Three Randomized Conditions:

  1. High-Intensity Intermittent (HI): $34\,\text{minutes}$. Alternated between $1\,\text{minute}$ running at $90\%$ $\text{VO}_2\text{max}$ and $1\,\text{minute}$ walking at $50\%$ $\text{VO}_2\text{max}$ ($16$ total intervals).

  2. Steady State (SS): $33\,\text{minutes}$ of continuous running at $70\%$ of $\text{VO}_2\text{max}$.

  3. Control (CON): $34\,\text{minutes}$ of quiet sitting.

• Calculations: Treadmill speeds for $50\%$, $70\%$, and $90\%$ $\text{VO}_2\text{max}$ were calculated using American College of Sports Medicine ($\text{ACSM}$) metabolic equations at $0\%$ grade. Resting $\text{VO}_2$ was assumed at $3.5\,\text{ml/kg/min}$.

Daily Session Procedures

• Fasted State: Subjects arrived between $6:00\text{ am}$ and $8:00\text{ am}$ in an $8$ to $10\text{ hour}$ fasted state.

• Standardized Supplement: Upon arrival, subjects consumed $20\,\text{oz}$ of original $\text{Gatorade}^{\circledR}$ (orange or fruit punch).

  • Content: $140\,\text{kcal}$, $36\,\text{g}$ carbohydrate, $0\text{g}$ fat, $0\text{g}$ protein.

• Preparation: Subjects sat for $60\,\text{minutes}$ post-beverage, followed by a $5\text{-minute}$ warm-up ($50\%$ $\text{VO}_2\text{max}$).

• Monitoring: HR recorded every minute; RPE recorded every $2\,\text{minutes}$. Followed by a $5\text{-minute}$ cool-down ($50\%$ $\text{VO}_2\text{max}$).

• Timeline: Sessions were completed on the same day of the week over three consecutive weeks.

Nutrition and Data Analysis

Food Logging

• Tracking: Food logs were kept $24\,\text{hours}$ before and $24\,\text{hours}$ after each exercise bout via the $\text{MyFitnessPal}$ mobile app/website.

• Verification: Subjects provided photographs of all food and drink.

• Metrics: Daily caloric intake ($\text{kcal}$), Carbohydrate ($\text{CHO}$), Protein ($\text{PRO}$), and Fat ($\text{FAT}$).

Statistical Analysis

• Tests used: One-way Repeated Measures Analysis of Variance ($\text{ANOVA}$).

• Post-hoc: Bonferroni analysis.

• Effect Size: Cohen’s Guidelines.

• Software: $\text{SPSS version 24.0}$.

• Significance level: $p \le 0.05$.

Results: Exercise Session Physiological Data

• Energy Expenditure (EE):

  • CON: $77 \pm 10\,\text{kcal}$.

  • HI: $321 \pm 73\,\text{kcal}$.

  • SS: $345 \pm 73\,\text{kcal}$.

  • Significance: CON was significantly lower than HI and SS (p < 0.001). No difference between HI and SS ($p = 0.49$).

• Rate of Perceived Exertion (RPE):

  • CON: $6 \pm 0$.

  • HI: $14 \pm 3$.

  • SS: $14 \pm 1$.

  • Significance: CON significantly lower than others (p < 0.001); no difference between HI and SS ($p = 0.81$).

• Heart Rate (HR):

  • CON: $68 \pm 10\,\text{bpm}$.

  • HI: $156 \pm 22\,\text{bpm}$.

  • SS: $157 \pm 21\,\text{bpm}$.

  • Significance: CON significantly lower (p < 0.001); no difference between HI and SS ($p = 0.67$).

Results: Dietary Intake and Compensation

Caloric Intake

• General Finding: No statistically significant difference in caloric intake between trials ($p = 0.23$ for trials; $p = 0.42$ between groups day before vs day after).

• Post-Exercise Data (Abstract Results):

  • CON: $1558 \pm 172\,\text{kcal}$.

  • HI: $1851 \pm 150\,\text{kcal}$.

  • SS: $1683 \pm 143\,\text{kcal}$.

• Trial Comparison (Pre vs Post from Table 1):

  • CON: Pre: $1614 \pm 106$ vs Post: $1557 \pm 172\,\text{kcal}$ (Effect size $d = -0.13$).

  • HI: Pre: $1553 \pm 114$ vs Post: $1850 \pm 150\,\text{kcal}$ (Effect size $d = 0.74$ - Medium-large).

  • SS: Pre: $1567 \pm 158$ vs Post: $1683 \pm 143\,\text{kcal}$ (Effect size $d = 0.26$ - Not notable).

Carbohydrate (CHO)

• Post-Exercise Data (Abstract Results): CON: $186 \pm 25\,\text{g}$, HI: $225 \pm 24\,\text{g}$, SS: $201 \pm 23\,\text{g}$ ($p = 0.41$).

• Trial Comparison (Pre vs Post):

  • HI Group: Pre: $166 \pm 19$ vs Post: $225 \pm 24\,\text{g}$. Large-very large effect size ($d = 0.91$).

  • CON & SS: No notable effect sizes ($d = -0.24$ and $0.27$ respectively).

Protein (PRO)

• Post-Exercise Data (Abstract Results): CON: $78 \pm 28\,\text{g}$, HI: $69 \pm 10\,\text{g}$, SS: $70 \pm 14\,\text{g}$ ($p = 0.64$).

• Trial Comparison (Pre vs Post):

  • SS Group: Pre: $73 \pm 12$ vs Post: $72 \pm 8\,\text{g}$. Medium-large effect size decrease ($d = -0.58$).

  • HI & CON: No notable clinical effect sizes.

Fat (FAT)

• Post-Exercise Data (Abstract Results): CON: $55 \pm 8\,\text{g}$, HI: $73 \pm 9\,\text{g}$, SS: $63 \pm 5\,\text{g}$ ($p = 0.16$).

• Statistical Significance: No notable differences between days or exercise sessions ($p = 0.30$).

Discussion and Practical Implications

Energy Deficits

• HI Trial: Caloric expenditure of exercise ($321\,\text{kcal}$) was nearly matched by an increase in caloric intake ($297\,\text{kcal}$), resulting in a minimal deficit of only $24\,\text{kcal}$.

• SS Trial: Caloric expenditure of exercise ($345\,\text{kcal}$) combined with a smaller increase in intake ($116\,\text{kcal}$) resulted in a much larger energy deficit of $229\,\text{kcal}$.

• Comparison to Literature: Findings align with some studies (Martins, 2015) while differing from others (Sim et al., 2014) that found lower energy intake after high intensity. The authors suggest this difference stems from their use of a free-living environment (eating at will) versus controlled liquid meals.

Exercise Mode Benefits

• For individuals seeking weight loss, the study suggests that Steady State exercise may be more effective for maintaining a caloric deficit than High-Intensity exercise, as HI showed a trend toward greater compensatory eating (specifically carbohydrates).

• HIIT remains a popular and enjoyable exercise mode (listed in top three Worldwide Fitness Trends since 2014), but users should be cautious of overeating afterward.

Study Limitations

• Menstrual Cycle: The cycle was not controlled, which is a known factor affecting appetite and macronutrient selection (increased intake often seen in the luteal phase).

• Population: The study focused on lean, recreationally active young individuals. Responses in obese individuals may differ due to leptin resistance and lower ghrelin levels.

• Recovery Energy Expenditure: Post-exercise energy expenditure (excess post-exercise oxygen consumption) was not measured, which could contribute to the overall energy deficit.

Conclusions

• Acute HI exercise did not lead to statistically significant different compensatory eating behaviors compared to SS exercise in healthy, lean young adults.

• Practitioners can recommend either exercise model (steady state or high-intensity interval training) for general fitness without high concern for massive overeating.

• However, if using High-Intensity exercise specifically for weight management, care should be taken as the medium-to-large effect sizes suggests individual tendencies toward increased carbohydrate consumption that could potentially negate the caloric benefits of the workout.