Table 1.
Participant demographics
| Morning | Intermediate | P Value | Cohen’s d Effect Size | |
|---|---|---|---|---|
| Participant characteristics | ||||
| n (male/female) | 23 (5/18) | 23 (4/19) | ||
| Age, yr | 54.7 ± 1.4 | 56.0 ± 1.8 | 0.590 | 0.160 |
| Body mass, kg | 94.6 ± 2.1 | 102.7 ± 4.4 | 0.121 | 0.484 |
| BMI, kg/m2 | 33.7 ± 0.6 | 37.2 ± 1.2 | 0.017 | 0.754 |
| Menopausal status, n | ||||
| Pre | 3 | 2 | ||
| Peri | 2 | 4 | ||
| Post | 13 | 13 | ||
| Race/ethnicity, n | ||||
| African American | 2 | 4 | ||
| Hispanic/Latino | 3 | 0 | ||
| White | 18 | 19 | ||
| MEQ score | 64.0 ± 1.0 | 51.4 ± 1.1 | <0.001 | 2.508 |
| Epworth sleepiness score | 6.52 ± 0.8 | 6.95 ± 0.9 | 0.717 | 0.113 |
| PSQI total score | 6.27 ± 0.5 | 5.35 ± 0.6 | 0.207 | 0.414 |
| PSQI 3-factor sleep efficiency | 1.4 ± 0.37 | 1.1 ± 0.21 | 0.456 | 0.234 |
| PSQI 3-factor perceived sleep quality | 3.28 ± 0.52 | 2.32 ± 0.50 | 0.192 | 0.422 |
| PSQI 3-factor daily disturbances | 2.67 ± 0.24 | 2.26 ± 0.19 | 0.192 | 0.401 |
| Body composition | ||||
| FFM, kg | 53.0 ± 1.3 | 50.6 ± 1.9 | 0.311 | 0.364 |
| Body fat, % | 43.5 ± 1.2 | 44.4 ± 1.0 | 0.584 | 0.179 |
| VAT volume, cm3 | 904.0 ± 43.9 | 981.3 ± 54.3 | 0.273 | 0.396 |
| Aerobic fitness | ||||
| V̇o2max, L/min | 2.3 ± 0.1 | 2.2 ± 0.1 | 0.438 | 0.234 |
| V̇o2max, mL/kg/min | 24.5 ± 0.9 | 21.0 ± 0.8 | 0.004 | 0.888 |
| V̇o2max, mL/FFM kg/min | 43.1 ± 1.4 | 37.9 ± 1.1 | 0.005 | 0.968 |
| V̇emax, L/min | 71.5 ± 2.2 | 71.0 ± 3.7 | 0.911 | 0.034 |
| HRmax, beats/min | 163.6 ± 2.4 | 157.3 ± 2.6 | 0.080 | 0.294 |
| RERmax, AU | 1.1 ± 0.02 | 1.1 ± 0.02 | 0.684 | 0.124 |
| RPEmax, AU | 17.4 ± 0.3 | 18.0 ± 0.3 | 0.182 | 0.399 |
| Cardiometabolic disease risk | ||||
| ATP III score | 3.5 ± 0.1 | 3.5 ± 0.2 | 0.910 | 0.021 |
| WC, cm | 107.8 ± 2.1 | 114.1 ± 3.0 | 0.094 | 0.505 |
| SBP, mmHg | 129.6 ± 3.1 | 133.8 ± 1.5 | 0.229 | 0.364 |
| DBP, mmHg | 77.9 ± 2.2 | 81.2 ± 1.7 | 0.251 | 0.347 |
| FPG, mmol/L* | 95.8 ± 2.8 | 100.0 ± 2.6 | 0.286 | 0.326 |
| TG, mmol/L | 137.2 ± 11.8 | 152.0 ± 10.9 | 0.362 | 0.282 |
| HDL-c, mmol/L | 46.4 ± 2.2 | 48.0 ± 1.8 | 0.579 | 0.169 |
| Fasting biochemistries | ||||
| Leptin, ng/mL* | 37.4 ± 5.4 | 57.4 ± 6.8 | 0.042 | 0.468 |
| Nitrate, mmol/L* | 32.5 ± 3.9 | 21.4 ± 2.3 | 0.022 | 0.901 |
| Nitrite, mmol/L* | 0.03 ± 0.004 | 0.02 ± 0.004 | 0.202 | 0.501 |
| Sodium, mmol/L | 140.1 ± 0.4 | 139.9 ± 0.4 | 0.647 | 0.137 |
| Chloride, mmol/L | 105.3 ± 0.4 | 105.0 ± 0.3 | 0.588 | 0.161 |
| Potassium, mmol/L | 4.1 ± 0.06 | 4.1 ± 0.07 | 0.635 | 0.150 |
| Hemoglobin, g/dL | 14.0 ± 0.3 | 13.8 ± 0.3 | 0.536 | 0.184 |
| Hematocrit, % | 42.2 ± 0.5 | 42.3 ± 0.7 | 0.600 | 0.158 |
Values are means ± SE; n, number of participants. Sample size and sex distribution between group differences are shown [Morn, n = 23 (18 females); and Int, n = 23 (19 females)]. ATP III score, adult treatment panel III quantified risk of metabolic syndrome; BMI, body mass index; DBP, diastolic blood pressure; FPG, fasting plasma glucose; HDL-c, high-density lipoprotein; MEQ score, Morning-Eveningness questionnaire score; RERmax, maximal respiratory exchange ratio; RPEmax, maximally achieved rate of perceived exertion based on the borg scale; SBP, systolic blood pressure; TG, triglycerides; VAT, visceral adipose tissue; V̇emax, maximal exercise ventilation; V̇o2max, aerobic capacity relative to mean body weight (kg) and fat free mass (FFM); WC, waist circumference.
*Reflects blood analytes measured during visit 3. All other biochemistries were obtained during visit 1. Independent sample t test was used to identify group differences between morning and intermediate chronotype. Effect size was calculated via Cohen’s d.