Protective effects of physical activity against health risks associated with type 1 diabetes: “Health benefits outweigh the risks”

Table 1 Summary of studies on exercise intervention in type 1 diabetes mellitus patients to improve glycemic control

Ref.	Year	Intervention	Findings
Sonnenberg et al[223]	1990	CSII during exercise	Hypoglycemia could only be avoided when the premeal insulin bolus was decreased by 50% and discontinuation of the basal insulin infusion during exercise
Rabasa-Lhoret et al[224]	2001	Premeal insulin dose reductions forpost-prandial exercises	Minimized risk of hypoglycemia during postprandial exercises of different intensities and different durations by a suitable decrease in premeal insulin lispro
Dubé et al[225]	2005	Glucose supplement during exercise in subjects using N-lispro	For 60 min of late post-prandial exercise followed by 60 min of recovery, an estimated 40 g of a liquid glucose supplement, ingested 15 min before exercise was good for BG control
Diabetes Research in Children Network (DirecNet) Study Group et al[211]	2006	Suspension of basal insulin during exercise	Basal insulin suspension decreases hypoglycemia from 43% to 16% in individuals, but hyperglycemia 45 min after exercise was more frequent
Bussau et al[226]	2006	Ten-second sprint after moderate-intensity exercise	This avoided early post-moderate intensity exercise hypoglycemia
Bussau et al[227]	2007	Ten-second sprint before moderate-intensity exercise	Prevented hypoglycemia during early recovery from moderate-intensity exercise
West et al[228]	2010	Reductions in pre-exercise rapid-acting insulin by 75%, 50%, or 25%	A 75% reduction in pre-exercise insulin resulted in the greatest preservation of BG, and a decreased dietary intake, for 24 h after running
Taplin et al[229]	2010	20% reduction of basal rate overnight	Was safe and effective in preventing nocturnal hypoglycemia
		2.5 mg bedtime dose of oral terbutaline	Effective at avoiding hypoglycemia, but linked with hyperglycemia
Riddell et al[219]	2011	RT-CGM and carbohydrate intake algorithm (8-20 g), depending on the concentration of glucose at the time of RT-CGM alert and rates of change in glycemia	The coupled carbohydrate intake algorithm with RT-CGM avoided hypoglycemia and maintained euglycemia during exercise
Garg et al[230]	2012	An automatic suspension of insulin delivery when BG ≤ 70 mg/dL during or after exercise	This significantly decreased the duration and severity of induced hypoglycemia without causing rebound hyperglycemia
Yardley et al[200]	2012	Resistance exercise before aerobic exercise	Performing resistance first improved glycemic stability throughout the exercise and decreased the duration and severity of post-exercise hypoglycemia
Yardley et al[231]	2013	Resistance vs aerobic exercise	Resistance caused a less initial decline in BG but prolonged decreases in post-exercise glycemia than aerobic exercise
Campbell et al[232]	2013	Pre- and post-exercise rapid-acting insulin reductions	25% pre-exercise and 50% post-exercise rapid-acting insulin dose preserved glycemia and protected patients against early-onset hypoglycemia (8 h)
Schiavon et al[233]	2013	In silico optimization of basal insulin infusion rate during exercise	A decrease in basal insulin by 50% starting 90 min before exercise and by 30% during exercise is safe and effective for glucose control
Danne et al[234]	2014	PLGM (suspension of insulin delivery based on predicted sensor glucose values)	PLGM may decrease the severity of hypoglycemia above that already established for algorithms that use a threshold-based suspension
Campbell et al[235]	2015	Combined basal-bolus insulin dose reduction and carbohydrate feeding strategy following exercise	Reducing basal-bolus insulin by 20% (80%) protected from nocturnal hypoglycemia for 24 h post-exercise
Cherubini et al[236]	2019	PLGM system during exercise	Effective for avoiding hypoglycemia during and after exercise, regardless of the thresholds of PLGM used
Moser et al[237]	2019	Oral administration of carbohydrates during moderate-intensity exercise	Pre-exercise BG levels determine the amount of orally administered carbohydrates during exercise to maintain euglycemia
Zaharieva et al[238]	2019	Basal rate reductions set 90 min pre-exercise vs pump suspension at exercise onset	50%-80% Basal rate reductions set 90 min pre-exercise improved BG control and reduced hypoglycemia risk during exercise better than pump suspension at exercise onset
Moser et al[239]	2019	Reduction in insulin degludec dose (75% IDeg dose vs 100% IDeg dose)	Reducing the usual IDeg dose by 25% led to more time spent in euglycemia with small effects on time spent in hypo- and hyperglycemia
Zaharieva et al[240]	2020	Insulin pump connected (pump on) vs pump disconnected (pump off) during high-intensity exercise	No significant differences in BG concentrations during 40 min of intermittent high-intensity exercise

CSII: Continuous subcutaneous insulin infusion; BG: Blood glucose; RT-CGM: Real-time continuous glucose monitoring; PLGM: Predictive low glucose management.