Title: The Effect of Exercise Frequency on Health Outcomes: A One Way ANOVA Analysis
Abstract
The purpose of this study was to examine the effect of different exercise frequency levels on various health outcomes using a one way analysis of variance (ANOVA). 90 adults between the ages of 18-65 were recruited and assigned to one of three groups based on their self-reported weekly exercise frequency: low (1-2 times/week), moderate (3-4 times/week) and high (5 or more times/week). Dependent variables measured included body mass index (BMI), blood pressure, glucose levels and cholesterol levels. Results of one way ANOVA tests revealed statistically significant differences between groups for BMI, systolic blood pressure and glucose levels, but not for cholesterol levels. Post hoc comparisons using Tukey’s HSD test indicated the high exercise frequency group had significantly lower BMI, systolic blood pressure and glucose compared to the low exercise frequency group. These findings provide support that higher exercise frequency confers greater health benefits and suggests public health recommendations should encourage exercising most days of the week.
Introduction
Regular physical activity is widely recommended for its numerous health benefits (Warburton et al., 2006). Current public health guidelines suggest adults aim for at least 150 minutes of moderate intensity aerobic activity or 75 minutes of vigorous intensity activity per week to gain health benefits (Department of Health and Human Services, 2018). Some research questions whether meeting the minimum weekly target is sufficient, or if health risks continue to decrease with even higher weekly amounts. Additionally, little is known about the impact of exercise frequency, independent of total weekly duration.
Distributing exercise evenly across the week rather than concentrating it into just a few sessions may provide additional benefits. For example, higher frequency would maintain more consistent cardiorespiratory fitness and body composition changes compared to intermittent bouts of exercise only a few times per week. This is important as sustained changes in fitness and weight status are likely needed to see long term health effects. Therefore, the purpose of this study was to examine the influence of different self-reported exercise frequency levels on common health outcomes using a one way ANOVA.
Methods
Participants
Ninety healthy adults between 18-65 years of age were recruited from a university campus and surrounding community. Participants were excluded if they reported any medical conditions that would preventthem from engaging in regular exercise or if they were already meeting public health exercise recommendations of 150 minutes per week. Eligible participants provided written informed consent and then completed a short demographic and exercise history questionnaire.
Measures
Exercise Frequency Groups – Based on reported average weekly exercise frequency over the past month, participants were assigned to one of three exercise frequency categories: Low (1-2 days/week), Moderate (3-4 days/week) and High (5 or more days/week).
Health Outcomes – Dependent variables assessed included:
Body Mass Index (BMI) – Calculated from measured height and weight.
Blood Pressure – Average of two seated measurements took 1-2 minutes apart using an automatic monitor.
Glucose – Fasting blood sample analyzed for glucose levels using a fingerstick monitor.
Total Cholesterol – Fasting blood sample analyzed for total cholesterol levels using a fingerstick monitor.
Procedure
Participants attended one lab session after an overnight fast. Height and weight were measured to calculate BMI. Blood pressure was measured while seated. A certified phlebotomist then drew a small fingerstick blood sample which was immediately analyzed for glucose and total cholesterol using a point-of-care monitor. Participants were later categorized into the low, moderate or high exercise frequency groups based on their baseline questionnaire responses. All procedures were approved by the university’s Institutional Review Board.
Data Analysis
One way analysis of variance (ANOVA) tests were conducted to examine differences between the three exercise frequency groups (independent variable) on each of the dependent health outcome variables (BMI, blood pressure, glucose, cholesterol). Post hoc comparisons using Tukey’s HSD test were performed for any variables showing a significant main effect. Statistical significance was set at p < 0.05. All analyses were performed using SPSS statistical software.
Andrew Stroud