Table 1

Cardiometabolic and glycemic outcome variables

80% BRR (At t = −90 min)50% BRR (At t = −90 min)PS (At t = 0 min)
Absolute VO2 (L/min)20.7 ± 3.3321.1 ± 3.6321.0 ± 3.33
20.1 (18.6–22.6)21.2 (18.8–22.8)20.9 (19.9–22.6)
Relative VO2 (%)49.8 ± 3.1150.7 ± 3.8950.5 ± 3.04
49.1 (47.7–52.6)49.4 (47.9–53.9)50.7 (48.7–52.4)
Heart rate (beats per min)122 ± 11124 ± 12124 ± 13
124 (118–130)130 (116–133)126 (118–133)
Exercise time:10–15 min55–60 min10–15 min55–60 min10–15 min55–60 min
Respiratory exchange ratio0.87 ± 0.040.86 ± 0.050.87 ± 0.050.86 ± 0.030.87 ± 0.050.88 ± 0.06
0.9 (0.8–0.9)0.9 (0.8–0.9)0.9 (0.8–0.9)0.9 (0.8–0.9)0.8 (0.8–0.9)0.9 (0.8–0.9)
Carbohydrate oxidation (g/min)2.06 ± 0.61.87 ± 0.52.15 ± 0.71.91 ± 0.51.84 ± 0.61.82 ± 0.7
1.9 (1.8–2.4)1.8 (1.6–2.1)2.1 (1.8–2.4)1.9 (1.7–2.0)1.7 (1.4–2.1)1.7 (1.5–1.8)
Fat oxidation (g/min)0.29 ± 0.10.32 ± 0.20.31 ± 0.10.32 ± 0.10.34 ± 0.20.31 ± 0.2
0.3 (0.2–0.4)0.3 (0.2–0.4)0.3 (0.2–0.4)0.3 (0.3–0.4)0.3 (0.3–0.4)0.3 (0.2–0.4)
Blood glucose (mg/dL) at exercise start164 ± 41191 ± 49*164 ± 45
157 (133–171)184 (153–221)157 (142–180)
∆Glucose (mg/dL) from start to end of exercise−31 ± 58−47 ± 50−67 ± 41
−32 (−74 to 11)−45 (−88 to −14)−65 (−90 to −38)
Decremental AUC−64 ± 110−89 ± 99−142 ± 81
−86 (−141 to 20)−86 (−143 to −6)−136 (−186 to −79)
Nadir glucose (mg/dL) during exercise122 ± 47137 ± 5097 ± 45
112 (86–146)148 (95–148)88 (67–103)
Time to first hypoglycemic event (min)453040 ± 11
45 (30–45)
Number of hypoglycemic events117*
Mealtime bolus insulin (unit)2.9 ± 1.13.1 ± 1.22.6 ± 1.1
2.6 (2.2–3.5)3.8 (1.9–3.9)2.3 (1.7–3.5)
  • Data are mean ± SD followed by median (IQR) unless otherwise indicated; n = 17. “10–15 min” and “55–60 min” refer to the last 5 min of the beginning and end of exercise when metabolic data were collected.

  • *Significantly different from the other two treatment arms (P < 0.05, one-way ANOVA).

  • †Significantly different from PS (P < 0.05, one-way ANOVA).