Biomarkers of insulin action during single soccer sessions before and after a 12-week training period in type 2 diabetes patients on a caloric-restricted diet

Background: We investigated the biomarkers of insulin action as well as changes in free fatty acids and lactate concentration after an acute soccer session pre and post training with caloric-restricted diet versus diet alone in type 2 diabetes (T2D) patients. Methods: Fifty-one middle-aged (61.1 +/- 6.4 years) T2D patients were randomly allocated to the soccer + diet group (SDG) or the diet group (DG). The control group comprised T2D patients observing a caloric-restricted diet who did not receive soccer training. Over 12 weeks, SDG performed 3 x 40 min per week of soccer training. Results: The first soccer session for SDG induced acute increases in blood lactate (1.4 +/- 0.1-6.0 +/- 0.7 mmol/l, P < 0.05) and glucagon levels (112.1 +/- 6.2-142.9 +/- 8.0 pg/ml, P < 0.05), whereas glucose and insulin levels remained unchanged. Moreover, this session showed suppressed insulin levels as well as higher free fatty acids, lactate levels and glucagon/insulin ratio compared to DG (p < 0.05). After 12 weeks, a baseline decrease was observed in glucagon, leptin and lactate levels in SDG and DG (p < 0.05), whereas HOMA-IR, Adipo-IR and glucose levels were lower only in SDG (p < 0.05). At the last soccer training session, the blood lactate response was significantly lower than for the first session (4.0 +/- 0.4 vs 6.0 +/- 0.7 mmol/l). At 48 h pre intervention, a decrease was observed in leptin levels (p < 0.05), which remained lower post intervention. The positive correlation between leptin and insulin, and the lower levels after training, could be attributed to the improved insulin sensitivity along with the weight loss observed in both groups (similar to 3.4 kg for DG and 3.7 kg for SDG). Conclusion: Acute soccer sessions markedly improved insulin action markers in T2D patients, while the cumulative effects enhanced insulin sensitivity and decreased risk factors associated with cardiovascular disease after 12 weeks of intervention better than caloric-restricted diet.