Reference No. of Subjects (males) Age (ys) Characteristics Intervention Outcome
HbA1c (%) Insulin doses/day    
Heyman et al. [107] 7 T1D (7) 7 CG 10.5 ± 0.3 10.3¬† 0.3 7.7 ± 0.7 0.92 ± 0.2 IU.kg-1.day-1 Evaluating aerobic fitness during an incremental maximal test and Aerobic power PWC170. [IA-DA-].¬† [PP]. Exercise ~ 2.25 h after insulin injection. - T1D pre-pubertal boys showed a significant ↓ in blood glucose during exercise.
Tansey et al. [108] 50 T1D (NA) 14.8 ± 1.7 7.8 ± 0.8 NA 1 x 75 min aerobic training session, heart rate 140 bpm. [IA+ DA +]. [PP]. - 30% of subjects became hypoglycaemic
- Blood glucose level significant ↓
Heyman et al. [97] 19 T1D (0) 19 CG 15.9 ± 0.3 16.6 ± 1.1 8.1 ± 0.3 68.3 ± 3.1 IU.day-1 Maximal incremental exercise test on a bicycle ergometer. [IA-DA-]. [PP]. Exercise ~ 2.25 h after insulin injection. - T1D adolescents (girls) showed a significant¬† ↓ in blood glucose during exercise.
Poortmans et al. [109] 17 T1D (17) 17 CG (17) 16.2 ± 0.7 16.6 ± 1.0 Good GC: 7.3 ± 0.3 Poor GC: 11.4 ± 0.9 Control: 6.3 ± 0.2 NA Maximal incremental exercise on bicycle ergometer. [IA-DA-]. [PP]. - Blood glucose levels significant ↓ more in well-controlled T1D compared with poor controlled T1D.
Guelfi et al. [110] 7 T1D (4) - ± 4 7.4 ± 1.5 14.8 ± 7.5 IU.day-1 A 30-min session of moderate continuous training (40% of VO2max.). [IA -DA-]. [PP]. - Capillary glucose level significant ↓
West et al. [111] 7 T1D (7) 31 ± 2 8.3 ± 0.1 NA Ingestion of 75 g CHO 30, 60, 90 and 120 min prior to a single session of 45 min of running exercise (70% of VO2max.). [IA+DA+]. [PP]. Insulin injection 30, 60, 90 and 120 min prior to the exercise. - 75g CHO 30 min before exercising decreases the incidence of hypoglycemic episodes and augments blood glucose levels after exercise compared to the ingestion of 75 g 60, 90 or 120 minutes before exercise.
Yamanouchi et al. [25] 6 T1D (3) 42.7 ± 13.6 7.4 ± 0.9 27.2 ± 9.4 IU.day-1 30 minutes of walking (< 50% of their VO2max) at a heart rate of 90-110 bpm, before or after breakfast. Subjects had 1 injection of regular insulin 30 min before breakfast: exercise after breakfast is performed while insulinaemia is high (peak of rapid insulin) whereas the exercise before breakfast is performed with low insulinaemia. [IA/DA+]. [FS and PP]. Exercise ~ 1h after insulin injection. - Blood glucose values significant ↓ when exercise is performed after breakfast, but not when exercise is performed before breakfast.
Zinman et al. [119] 16 T1D (10) 30 (22-43) NA NA 45 min at 50% of VO2max. [IA infusion, DA NA] 2 groups: 1 group continuous insulin infusion, 1 group received one-third of usual intermediate acting insulin by subcutaneous injection. [FS]. Exercise ~ 1h after insulin injection. - Rapid ↓ in glucose in subjects receiving one third of usual insulin. [P] glucose during exercise is constant in subjects with iv insulin infusion.
Zinman et al. [124] 13 T1D (7) 30.0 ± 1.8 10.7 ± 0.3 → 10.3 ± 0.8 37.6 ± 3.2 IU.day-1 A 45-min session of aerobic exercise (60-85% of their VO2max.). [IA-DA- (daily routines)]. [PAS, PP, FS = NA]. Exercise ~ 45 -135 min after insulin injection. - Plasma glucose significant ↓
*Data presented as mean ± SD; N° of Subjects (males) = total number of subjects and the number between brackets are the number of males; T1D: Type 1 Diabetes; GC: Glycaemic Control; NA: Not Applicable; CG: Controls; CHO: Carbohydrates; [VP]: Venous Plasma Glucose; [V]: Venous Whole blood, [P]: Plasma; [C]: Capillary; IA: Insulin Advice before/after Exercise; DA: Dietary Advice before/during or after Exercise; iv: intra-venous; ↓: Decrease; [PAS]: Post Absorptive State (5-11h after last meal); [PP]: Post Prandial (during 4h after meal); [FS]: Fasting State (> 12h after meal); HbA1c: Glycaeted Haemoglobin; VO2max: Maximal Oxygen Uptake; PWC: Physical Working Capacity
Table 1: Effects of a single bout of aerobic exercise on blood glucose levels in T1D patients. (Table based on [100]).