Table 1.

Summary of clinical trials examining the impact of metformin in combination with exercise on glycemic control compared to exercise alone.

Study details	Prescription/Population	FPG	2-h Postprandial	HbA1c
Ramachandran et al. (24)	Walk or cycle >30 min/d + 1,000 mg/d metformin for ~3 years in overweight/obese adults	↔	↔ during OGTT	N/A
Sharoff et al. (23)	An acute bout of cycle ergometry for 30 min @ 65% VO2Peak + 2–3 weeks of 2,000 mg/d metformin treatment prior in overweight/obese adults	↔	N/A	N/A
Love-Osborne et al. (25)	Self-chosen life style change + 1,700 mg/d metformin for 6 months in overweight/obese adolescents	↔	↔ during OGTT	N/A
Erickson et al. (26)	Postmeal exercise (5 x 10-min bouts of treadmill walking at 60% VO2Peak) + 1,000–2,000 mg/d metformin in overweight/obese adults	N/A	↓ during MMTT	N/A
Ortega et al. (27)	An acute bout of exercise + physician prescribed dose of metformin in insulin-resistant adults	N/A	↔ during OGTT	N/A
Boulé et al. (31)	~33 submaximal exercise bouts lasting 3–15 min @ 67–79% VO2Peak + 28 d of 2,000 mg/d metformin treatment prior in adults with T2D.	↑	↑ during MMTT	N/A
Terada and Boulé (30)	Nutrition intervention/with ≥175 min exercise/wk + metformin therapy in overweight adults with T2D	↑	N/A	↑
Malin et al. (32)	60–75 min of moderate-high intensity concurrent training 3 d/wk + of 2,000 mg/d metformin administration for 12 weeks in adults with prediabetes	↔	N/A	N/A
Konopka et al. (33)	45 min of moderate-high intensity cycle ergometry 3 d/wk + 2,000 mg/d metformin for 12 weeks in older adults with prediabetes	↔	N/A	↔
Walton et al. (34)	PRT + 1,700 mg/d metformin for 14 weeks in healthy older adults	↔	N/A	N/A

FPG, fasting plasma glucose; OGTT, oral glucose tolerance test; MMTT, mixed meal tolerance test; N/A, Not applicable because the measurement was either not reported or measured; ↑, higher; ↓, lower; ↔, no difference.