3.1. Participant characteristics
Sixty-five participants were enrolled in the study. Eight participants were excluded (intensity of exercise session not at 60% VO2peak [n = 6], no exercise data [n = 2]); hence 57 participants were included in our analyses. Baseline characteristics of all included participants (mean age 21.7 [SD = 2.5] years, mean BMI 23.7 [SD = 2.3], 75% White, 54% female) are presented in Table 1. Weight, percent body fat, FFM, VO2peak, and maximal power differed by sex (all P ≤ 0.001), all other characteristics did not differ between men and women (all P ≥ 0.26). On average, participants expended 343 (SD = 85) kcal during the 45-minute exercise session and consumed 867 (SD = 411) kcal during the post-exercise ad libitum test meal. Relative to the energy expended during the exercise sessions, participants consumed 526 (SD = 406) kcal during the post-exercise test meal (compensatory intake). After the rest condition, energy intake during the test meal was 821 (SD = 383) kcal with an average difference in intake between the two test meals of 46 (SD = 303) kcal (P = 0.26). Exercise-related energy expenditure and energy intake during the test meals by sex are presented in Table 1.
Table 1
Participant characteristics.
|
All (N = 57)
|
Men (n = 26)
|
Women (n = 31)
|
Race/Ethinicity, n (%)
|
|
|
|
|
|
|
|
White
|
43
|
(75.4)
|
18
|
(69.3)
|
25
|
(80.6)
|
|
African American
|
9
|
(15.8)
|
6
|
(23.1)
|
3
|
(9.7)
|
|
Asian
|
4
|
(7.0)
|
1
|
(3.8)
|
3
|
(9.7)
|
|
Other
|
1
|
(1.8)
|
1
|
(3.8)
|
0
|
(0.0)
|
|
Mean
|
(SD)
|
Mean
|
(SD)
|
Mean
|
(SD)
|
Age, years
|
21.7
|
(2.5)
|
21.4
|
(2.4)
|
21.9
|
(2.6)
|
Weight, kg
|
68.7
|
(10.2)
|
73.6
|
(11.3)
|
64.6
|
(7.0)
|
BMI, kg/m2
|
23.7
|
(2.3)
|
23.8
|
(2.7)
|
23.5
|
(2.1)
|
Fat-free mass, kg
|
59.6
|
(9.0)
|
66.0
|
(8.9)
|
54.2
|
(4.6)
|
Total body fat, %
|
13.2
|
(6.0)
|
9.9
|
(5.4)
|
15.9
|
(5.1)
|
Physical activity behavior and cardiorespiratory fitness
|
Total habitual exercise, min/week a
|
245.9
|
(181.2)
|
236.0
|
(137.7)
|
254.4
|
(213.9)
|
Habitual exercise days, days/week
|
3.4
|
(1.9)
|
3.7
|
(1.9)
|
3.3
|
(2.0)
|
MVPA, min/week
|
332.4
|
(145.7)
|
350.4
|
(159.9)
|
317.3
|
(133.4)
|
Relative VO2peak, mL/kg/min
|
37.4
|
(6.2)
|
40.6
|
(5.8)
|
34.7
|
(5.2)
|
Absolute VO2peak, L/min
|
2.6
|
(0.6)
|
2.3
|
(0.6)
|
2.2
|
(0.3)
|
Maximal power, W b
|
220.6
|
(48.5)
|
248.5
|
(47.6)
|
196.5
|
(34.8)
|
Appetitive traits
|
|
|
|
|
|
|
Cognitive Restraint via TFEQ-R18v2
|
5.9
|
(2.2)
|
5.7
|
(2.6)
|
6.0
|
(1.8)
|
Uncontrolled Eating via TFEQ-R18v2
|
17.3
|
(4.7)
|
17.6
|
(4.9)
|
17.0
|
(4.5)
|
Emotional Eating via TFEQ-R18v2
|
9.8
|
(3.3)
|
9.2
|
(2.7)
|
10.2
|
(3.7)
|
Appetite-regulating hormones c
|
|
|
|
|
|
|
GLP-1, pg/mL d
|
10.9
|
(5.2)
|
10.0
|
(4.4)
|
11.4
|
(5.8)
|
PYY, pg/mL d
|
110.8
|
(47.0)
|
110.4
|
(46.5)
|
111.1
|
(48.4)
|
Ghrelin, pg/mL e
|
865.2
|
(393.0)
|
807.3
|
(435.0)
|
906.5
|
(365.3)
|
Adiponectin, ng/mL f
|
11.7
|
(7.1)
|
8.9
|
(6.4)
|
13.8
|
(6.9)
|
Exercise session
|
|
|
|
|
|
|
Energy expenditure, kcal
|
343
|
(85)
|
400
|
(85)
|
296
|
(46)
|
Test meal
|
|
|
|
|
|
|
Energy intake (post exercise), kcal
|
867
|
(411)
|
1010
|
(478)
|
748
|
(304)
|
Energy Intake (post rest), kcal
|
821
|
(383)
|
999
|
(376)
|
672
|
(326)
|
Difference in energy intake, kcal g
|
46
|
(303)
|
11
|
(398)
|
75
|
(193)
|
Compensatory energy intake, kcal h
|
526
|
(406)
|
609
|
(482)
|
452
|
(320)
|
Data are mean (standard deviation) unless stated otherwise. Weight, percent body fat, FFM, VO2peak, and maximal power differed by sex (all P≤0.001), all other characteristics did not differ between men and women (all P≥0.26).
a Data available for 54/57 participants (25/26 men and 29/31 women).
b Data available for 56/57 participants (26/26 men and 30/31 women).
c Hormone concentrations are reported as means between pre-exercise and pre-rest. Fasting concentrations before the two study conditions did not differ (all P≥0.08).
d Data available for 39/57 participants (16/26 men and 23/31 women).
e Data available for 36/57 participants (15/26 men and 21/31 women).
f Data available for 38/57 participants (16/26 men and 22/31 women).
g Post-exercise ad libitum energy intake (kcal) – energy intake following the rest condition (kcal).
h Energy intake during test meal (kcal) – energy expenditure during exercise session (kcal)
Abbreviations: BMI, body mass index; GLP-1, Glucagon-like Peptide 1; MVPA, moderate-to-vigorous physical activity; PYY, peptide YY; SD, standard deviation; TFEQ-R18v2, revised 18-item Three-Factor Eating Questionnaire.
3.2 Predictors of total post-exercise energy intake
Total post-exercise energy intake was inversely associated with habitual exercise behavior (β=−0.29, P=0.032; Table 2, Figure 1A) and positively associated with FFM (β=0.30, P=0.025; Table 2) and fasting concentrations of PYY (β=0.39, P=0.015; Table 2, Figure 1D). We also found a sex effect, as men consumed on average 261.9 kcal more than women (P=0.015). After stratifying by sex, PYY (β=0.88, P<0.001) and additionally adiponectin (β=0.66, P=0.005, Table 2, Figure 1G) were significant predictors of total post-exercise energy intake only in men, while habitual exercise (β=−0.44, P=0.017) was a significant predictor of total post-exercise energy intake only in women.
Table 2
Linear regression analysis for the association between anthropometrics, physiological and behavioral baseline characteristics and total energy intake during the post-exercise ad libitum test meal.
|
All participants
|
Men
|
Women
|
|
Energy intake (kcal)
|
Energy intake (kcal)
|
Energy intake (kcal)
|
|
R2
|
B
|
SE
|
β
|
P
|
R2
|
B
|
SE
|
β
|
P
|
R2
|
B
|
SE
|
β
|
P
|
Sex a
|
0.103
|
261.9
|
104.5
|
0.32
|
0.015
|
|
|
|
|
|
|
|
|
|
|
Age, years
|
0.000
|
−2.3
|
22.3
|
−0.01
|
0.920
|
0.002
|
−8.2
|
40.0
|
−0.04
|
0.840
|
0.008
|
10.7
|
22.0
|
0.090
|
0.632
|
Weight, kg
|
0.052
|
9.2
|
5.3
|
0.23
|
0.088
|
0.022
|
6.2
|
8.5
|
0.15
|
0.471
|
0.000
|
0.2
|
8.1
|
0.00
|
0.979
|
BMI, kg/m2
|
0.009
|
16.8
|
23.5
|
0.10
|
0.477
|
0.000
|
2.9
|
36.4
|
0.02
|
0.937
|
0.034
|
27.0
|
26.9
|
0.18
|
0.323
|
Fat-free mass, kg
|
0.088
|
13.5
|
5.9
|
0.30
|
0.025
|
0.059
|
13.1
|
10.7
|
0.24
|
0.233
|
0.031
|
−11.6
|
12.0
|
−0.18
|
0.340
|
Total body fat, %
|
0.018
|
−9.4
|
9.2
|
−0.14
|
0.315
|
0.016
|
−11.2
|
18.1
|
−0.13
|
0.542
|
0.060
|
14.7
|
10.8
|
0.25
|
0.183
|
Physical activity behavior and cardiorespiratory fitness
|
Habitual exercise, min/week
|
0.085
|
−0.7
|
0.3
|
−0.29
|
0.032
|
0.032
|
−0.6
|
0.7
|
−0.18
|
0.395
|
0.194
|
−0.6
|
0.3
|
−0.44
|
0.017
|
Habitual exercise days/week
|
0.024
|
−33.0
|
28.1
|
−0.16
|
0.246
|
0.013
|
−28.9
|
50.6
|
−0.12
|
0.572
|
0.103
|
−49.3
|
27.0
|
−0.32
|
0.078
|
MVPA, min/week
|
0.012
|
0.3
|
0.4
|
0.11
|
0.418
|
0.019
|
0.4
|
0.6
|
0.14
|
0.498
|
0.000
|
0.0
|
0.4
|
−0.02
|
0.924
|
Relative VO2peak, mL/kg/min
|
0.000
|
1.2
|
9.0
|
0.02
|
0.896
|
0.009
|
−7.8
|
16.8
|
−0.09
|
0.648
|
0.074
|
−16.0
|
10.5
|
−0.27
|
0.138
|
Absolute VO2peak, L/min
|
0.021
|
97.5
|
90.2
|
0.14
|
0.284
|
0.000
|
9.4
|
158.1
|
0.01
|
0.953
|
0.083
|
−270.1
|
166.2
|
−0.29
|
0.115
|
Maximal power, W
|
0.049
|
1.9
|
1.1
|
0.22
|
0.101
|
0.015
|
1.2
|
2.0
|
0.12
|
0.558
|
0.003
|
−0.5
|
1.7
|
−0.05
|
0.781
|
Appetitive traits
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cognitive Restraint
|
0.013
|
−21.4
|
25.3
|
−0.11
|
0.401
|
0.058
|
−44.1
|
36.3
|
−0.24
|
0.237
|
0.040
|
34.5
|
31.5
|
0.20
|
0.282
|
Uncontrolled Eating
|
0.010
|
8.9
|
11.9
|
0.10
|
0.455
|
0.004
|
−6.2
|
19.7
|
−0.06
|
0.757
|
0.091
|
20.6
|
12.1
|
0.30
|
0.098
|
Emotional Eating
|
0.002
|
5.8
|
16.9
|
0.05
|
0.732
|
0.011
|
−18.0
|
35.5
|
−0.10
|
0.618
|
0.097
|
26.0
|
14.7
|
0.31
|
0.087
|
Appetite-regulating hormones
|
GLP-1, pg/mL
|
0.000
|
0.7
|
12.8
|
0.09
|
0.957
|
0.108
|
38.4
|
29.5
|
0.33
|
0.214
|
0.036
|
−8.4
|
9.5
|
−0.19
|
0.388
|
PYY, pg/mL
|
0.149
|
3.3
|
1.3
|
0.39
|
0.015
|
0.775
|
9.6
|
1.4
|
0.88
|
< 0.001
|
0.013
|
−0.6
|
1.1
|
−0.12
|
0.600
|
Ghrelin, pg/mL
|
0.005
|
0.1
|
0.2
|
0.07
|
0.681
|
0.087
|
0.3
|
0.3
|
0.30
|
0.285
|
0.021
|
−0.1
|
0.2
|
−0.14
|
0.535
|
Adiponectin, ng/mL
|
0.043
|
12.0
|
9.5
|
0.21
|
0.213
|
0.438
|
52.9
|
16.0
|
0.66
|
0.005
|
0.010
|
3.8
|
8.4
|
0.10
|
0.659
|
Bold font indicates statistical significance (P < 0.05). Dependent variable in all models: Total energy intake during the post-exercise ad libitum test meal (kcal). |
a Female = 0, male = 1. |
Abbreviations: B, unstandardized regression coefficient; β, standardized regression coefficient; BMI, body mass index; GLP-1, Glucagon-like Peptide 1; MVPA, moderate-to-vigorous physical activity; PYY, peptide YY; SE, standard error. |
3.3 Predictors of compensatory energy intake
Similar to total post-exercise energy intake, compensatory energy intake was inversely associated with habitual exercise behavior (β=−0.31, P=0.024; Table 3, Figure 1B) and positively associated with fasting concentrations of PYY (β=0.37, P=0.021; Table 3, Figure 1E). Similar to total post-exercise energy intake, PYY (β=0.85, P<0.001) and additionally adiponectin (β=0.69, P=0.003; Table 3, Figure 1H) were significant predictors of compensatory energy intake only in men, while habitual exercise (min/week: β=−0.44, P=0.016; days/week: β=−0.39, P=0.032) and additionally VO2peak (relative: β=−0,36, P=0.044; absolute: β=−0.42; P=0.020; Table 3) were significant predictors of compensatory energy intake only in women.
Table 3
Linear regression analysis for the association between anthropometrics, physiological and behavioral baseline characteristics and compensatory post-exercise ad libitum energy intake (energy intake [kcal] – energy expenditure [kcal]).
|
All participants
|
Men
|
Women
|
|
Compensatory energy intake (kcal)
|
Compensatory energy intake (kcal)
|
Compensatory energy intake (kcal)
|
|
R2
|
B
|
SE
|
β
|
P
|
R2
|
B
|
SE
|
β
|
P
|
R2
|
B
|
SE
|
β
|
P
|
Sex a
|
0.038
|
157.4
|
106.9
|
0.19
|
0.147
|
|
|
|
|
|
|
|
|
|
|
Age, years
|
0.000
|
−2.0
|
22.0
|
−0.01
|
0.929
|
0.007
|
−16.1
|
40.3
|
−0.08
|
0.693
|
0.012
|
13.8
|
23.1
|
0.11
|
0.554
|
Weight, kg
|
0.007
|
3.4
|
5.4
|
0.09
|
0.528
|
0.000
|
0.9
|
8.7
|
0.02
|
0.923
|
0.002
|
−2.0
|
8.5
|
−0.04
|
0.816
|
BMI, kg/m2
|
0.000
|
3.0
|
23.3
|
0.02
|
0.899
|
0.007
|
−14.5
|
36.6
|
−0.08
|
0.695
|
0.020
|
21.8
|
28.5
|
0.14
|
0.449
|
Fat-free mass, kg
|
0.019
|
6.1
|
6.0
|
0.14
|
0.312
|
0.013
|
6.1
|
11.0
|
0.11
|
0.583
|
0.054
|
−16.0
|
12.5
|
−0.23
|
0.209
|
Total body fat, %
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Physical activity behavior and cardiorespiratory fitness
|
Habitual exercise, min/week
|
0.094
|
−0.7
|
0.3
|
−0.31
|
0.024
|
0.035
|
−0.6
|
0.7
|
−0.19
|
0.372
|
0.197
|
−0.7
|
0.3
|
−0.44
|
0.016
|
Habitual exercise days/week
|
0.054
|
−48.7
|
27.4
|
−0.23
|
0.081
|
0.028
|
−41.9
|
50.6
|
−0.17
|
0.416
|
0.149
|
−62.4
|
27.6
|
−0.39
|
0.032
|
MVPA, min/week
|
0.012
|
0.3
|
0.4
|
0.11
|
0.419
|
0.027
|
0.5
|
0.6
|
0.16
|
0.421
|
0.001
|
−0.1
|
0.4
|
−0.02
|
0.900
|
Relative VO2peak, mL/kg/min
|
0.019
|
−9.1
|
8.8
|
−0.14
|
0.306
|
0.043
|
−17.3
|
16.7
|
−0.21
|
0.312
|
0.133
|
−22.6
|
10.7
|
−0.36
|
0.044
|
Absolute VO2peak, L/min
|
0.004
|
−40.1
|
89.9
|
−0.06
|
0.657
|
0.026
|
−127.0
|
157.4
|
−0.16
|
0.428
|
0.173
|
−408.6
|
166.0
|
−0.42
|
0.020
|
Maximal power, W
|
0.001
|
0.3
|
1.1
|
0.04
|
0.781
|
0.001
|
−0.4
|
2.1
|
−0.04
|
0.853
|
0.027
|
−1.5
|
1.7
|
−0.16
|
0.386
|
Appetitive traits
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cognitive Restraint
|
0.012
|
−20.4
|
25.0
|
−0.11
|
0.420
|
0.050
|
−41.2
|
36.8
|
−0.22
|
0.274
|
0.021
|
26.4
|
33.4
|
0.15
|
0.436
|
Uncontrolled Eating
|
0.008
|
7.7
|
11.7
|
0.09
|
0.517
|
0.008
|
−8.5
|
19.9
|
−0.09
|
0.671
|
0.094
|
22.0
|
12.7
|
0.31
|
0.093
|
Emotional Eating
|
0.004
|
7.4
|
16.7
|
0.06
|
0.660
|
0.016
|
−22.6
|
35.7
|
−0.13
|
0.532
|
0.095
|
27.0
|
15.5
|
0.31
|
0.092
|
Appetite-regulating hormones
|
GLP-1, pg/mL
|
0.002
|
3.0
|
12.5
|
0.04
|
0.811
|
0.108
|
38.8
|
29.8
|
0.33
|
0.214
|
0.024
|
−7.5
|
10.3
|
−0.16
|
0.477
|
PYY, pg/mL
|
0.136
|
3.1
|
1.3
|
0.37
|
0.021
|
0.724
|
9.4
|
1.6
|
0.85
|
< 0.001
|
0.022
|
−0.8
|
1.2
|
−0.15
|
0.501
|
Ghrelin, pg/mL
|
0.018
|
0.1
|
0.2
|
0.14
|
0.431
|
0.090
|
0.4
|
0.3
|
0.30
|
0.278
|
0.001
|
−0.0
|
0.2
|
−0.03
|
0.911
|
Adiponectin, ng/mL
|
0.066
|
14.6
|
9.2
|
0.26
|
0.120
|
0.476
|
55.8
|
15.6
|
0.69
|
0.003
|
0.001
|
1.3
|
9.0
|
0.03
|
0.888
|
Bold font indicates statistical significance (P < 0.05). Dependent variable in all models: Compensatory post-exercise ad libitum energy intake (energy intake during test meal [kcal] – energy expenditure during exercise session [kcal]). |
a Female = 0, male = 1. |
Abbreviations: B, unstandardized regression coefficient; β, standardized regression coefficient; BMI, body mass index; GLP-1, Glucagon-like Peptide 1; MVPA, moderate-to-vigorous physical activity; PYY, peptide YY; SE, standard error. |
3.4 Predictors of post-rest energy intake
Energy intake after the rest condition was positively associated with weight (β=0.35, P=0.008), FFM (β=0.38, P=0.004) and aerobic fitness as measured by absolute VO2peak (β=0.43, P<0.001) and maximal power during the exercise test (β=0.43, P<0.001; Supplemental Table 1). Similar to post-exercise, post-rest energy intake differed by sex (P<0.001). Absolute VO2peak (β=0.53, P=0.006) and maximal power (β=0.54, P=0.005) were only associated with ad libitum energy intake in men, while in women, only habitual exercise minutes per week was a significant predictor of ad libitum energy intake (β=−0.37, P=0.048).
3.5 Predictors of the difference between post-exercise and post-rest energy intake
The difference in total energy intake between exercise and rest was inversely associated with aerobic fitness as measured by relative (β=−0.31, P=0.020) and absolute (β=−0.35, P=0.008) VO2peak. The difference between exercise and rest was also positively associated with fasting PYY concentrations (β=0.33, P=0.038; Supplemental Table 2, Figure 1F). Notably, significant associations were driven by men, and they were not significant for women (Supplemental Table 2). In men, above a VO2peak cut point of 40.9 mL/kg/min (3.0 L/min), post-rest energy intake was greater than post-exercise energy intake, while below the cut point, post-exercise energy intake was greater than post-rest energy intake. For PYY in men, post-exercise energy intake was greater than post-rest energy intake above the cut point of 118.6 pg/mL, while below the cut point, post-rest energy intake was greater than post-exercise energy intake.