Interindividual responses of appetite to acute exercise: a replicated crossover study

Purpose: Acute exercise transiently suppresses appetite, which coincides with alterations in appetite-regulatory hormone concentrations. Individual variability in these responses is suspected, but replicated trials are needed to quantify them robustly. We examined the reproducibility of appetite and appetite-regulatory hormone responses to acute exercise and quantified the individual differences in responses. Methods: Fifteen healthy, recreationally-active men completed two control (60-min resting) and two exercise (60-min fasted treadmill running at 70% peak oxygen uptake) conditions in randomised sequences. Perceived appetite and circulating concentrations of acylated ghrelin and total peptide YY (PYY) were measured immediately before and after the interventions. Inter-individual differences were explored by correlating the two sets of response differences between exercise and control conditions. Within-participant covariate-adjusted linear mixed models were used to quantify participant-by-condition interactions. Results: Compared with control, exercise suppressed mean acylated ghrelin concentrations and appetite perceptions (all ES = 0.62 to 1.47, P < 0.001), and elevated total PYY concentrations (ES = 1.49, P < 0.001). For all variables, the SD of the change scores was substantially greater in the exercise versus control conditions. Moderate-to-large positive correlations were observed between the two sets of control-adjusted exercise responses for all variables (r = 0.54 to 0.82, P ≤ 0.036). After adjusting for baseline measurements, participant-by-condition interactions were present for all variables (P ≤ 0.053). Conclusion: Our replicated cross-over study allowed, for the first time, the interaction between participant and acute exercise response in appetite parameters to be quantified. Even after adjustment for individual baseline measurements, participants demonstrated individual differences in perceived appetite and hormone responses to acute exercise bouts beyond any random within-subject variability over time

Scatter plot of the changes over time in energy cost (Kcal∙km^-1) adjusted for body mass (BM) vs the changes over time in V̇O_2max (L∙min^-1) adjusted for BM (r = 0.35; P &lt; 0.001) within the longitudinal analysis.

<p>Scatter plot of the changes over time in energy cost (Kcal∙km^-1) adjusted for body mass (BM) vs the changes over time in V̇O_2max (L∙min^-1) adjusted for BM (r = 0.35; P &lt; 0.001) within the longitudinal analysis.</p

Scatter plot of energy cost (Kcal∙km^-1) adjusted for body mass (BM) vs V̇O_2max (L∙min^-1) adjusted for BM for both females (A; <i>n</i> = 70; r = 0.25; <i>P</i> = 0.036) and males (B; <i>n</i> = 98; r = 0.26; <i>P</i> = 0.0

<p>Scatter plot of energy cost (Kcal∙km^-1) adjusted for body mass (BM) vs V̇O_2max (L∙min^-1) adjusted for BM for both females (A; <i>n</i> = 70; r = 0.25; <i>P</i> = 0.036) and males (B; <i>n</i> = 98; r = 0.26; <i>P</i> = 0.009) within the cross-sectional analysis.</p

Physiological and anthropometrical characteristics of athletes within the cross sectional and longitudinal investigations.

<p>V̇O_2max, maximal oxygen uptake; vLTP, velocity at lactate turnpoint.</p><p>Physiological and anthropometrical characteristics of athletes within the cross sectional and longitudinal investigations.</p

SAS codes from A comprehensive allometric analysis of 2nd digit length to 4th digit length in humans

SAS code

2d4d ratio - Right hand data from A comprehensive allometric analysis of 2nd digit length to 4th digit length in humans

2nd and 4th digit measurements in the right han

2d4d ratio - Left hand data from A comprehensive allometric analysis of 2nd digit length to 4th digit length in humans

2nd and 4th digit measurements in the left han

Are there interindividual responses of cardiovascular disease risk markers to acute exercise? A replicated crossover study

Purpose: Using a replicated crossover design, we quantified the response heterogeneity of postprandial cardiovascular disease (CVD) risk marker responses to acute exercise. Methods: Twenty men (mean (SD) age, 26 (6) years; BMI, 23.9 (2.4) kg·m-2) completed four, 2-day conditions (two control, two exercise) in randomised orders. On days 1 and 2, participants rested and consumed two high-fat meals over 9-h. Participants ran for 60-mins (61 (7)% of peak oxygen uptake) on day 1 (6.5-7.5 h) of both exercise conditions. Time-averaged total-area-under-the-curve (TAUC) for triacylglycerol (TAG), glucose and insulin were calculated from 11 venous blood samples on day 2. Arterial stiffness and blood pressure responses were calculated from measurements at baseline on day 1 and at 2.5-h on day 2. Consistency of individual differences was explored by correlating the two replicates of control-adjusted exercise responses for each outcome. Within-participant covariate-adjusted linear mixed models quantified participant-by-condition interactions and individual-response SDs. Results: Acute exercise reduced mean TAUC-TAG (-0.27 mmol·L-1 h; Cohen’s d = 0.29, P = 0.017) and TAUC-insulin (-24.45 pmol·L-1 h; Cohen’s d = 0.35, P = 0.022) vs. control, but led to negligible changes in TAUC-glucose and the vascular outcomes (Cohen’s d ≤ 0.41, P ≥ 0.106). Small-to-moderate, but nonsignificant, correlations were observed between the two response replicates (r = -0.40 to 0.15, P ≥ 0.066). We did not detect any individual response heterogeneity. All participant-by-condition interactions were P ≥ 0.137, and all individual-response SDs were small with wide 95% confidence intervals overlapping zero. Conclusion: Large trial-to-trial within-subject variability inhibited detection of consistent inter-individual variability in postprandial metabolic and vascular responses to acute exercise.</p

One-year weight loss separated by pain classification group.

<p>One-year weight loss separated by pain classification group.</p

Key characteristics for complete case and missing data groups.

<p>Key characteristics for complete case and missing data groups.</p