Advanced diabetes technologies supporting marathon training in type 1 diabetes

A. Pirazzi,¹ E. Larnè,¹ M. Giuriato,¹ C. Cavallo,^1,2 V. Carnevale Pellino,¹ A. Gatti,^1,3 E. Durando,¹ M. Vandoni,¹ A. Alberico¹ | ¹Laboratory of Adapted Motor Activity, Department of Public Health, Experimental Medicine and Forensic Science, University of Pavia, Italy; ²Luxembourg Health & Sport Sciences Research Institute A.s.b.l., Differdange, Luxembourg; ³National PhD Programme in One Health approaches to infectious diseases and life science research, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Italy

Diabetes technologies have transformed the management of type 1 diabetes (T1D). In marathon runners with T1D, optimal glycemic management is a key determinant of training quality and competition performance. Advanced diabetes technologies facilitate real-time glucose monitoring and adaptive insulin adjustments during endurance training, which requires a careful balance of exercise intensity and insulin therapy to ensure metabolic safety. This study examines the contribution of advanced diabetes technologies and wearable devices to marathon preparation in a recreational athlete with T1D. A 32-year-old woman with T1D completed a 12-month structured marathon training program. The program comprised 5 weekly sessions: 3 running and 2 functional strength training. Monthly running volume is 70±15 kilometers, and workouts alternated interval training sessions, tempo runs, and long slow distance runs. Glycemic patterns and insulin delivery were continuously monitored using a Tandem insulin pump integrated with a Dexcom G7 continuous glucose monitoring system. Training load, heart rate, and running metrics were systematically recorded throughout the intervention using a Garmin Venu 3 smartwatch. Over the 12-month training period, the athlete showed a progressive improvement in aerobic capacity and endurance-related performance. The marathon was completed in 3:39:31. Resting heart rate decreased from 61 to 55 bpm. Total daily insulin requirements increased by 27% over the training period, alongside an increase in daily carbohydrate intake from 146 g to 210 g. Continuous glucose monitoring data were available for 94% of the training sessions, covering 244 out of 260 sessions. Advanced diabetes technologies and wearable devices enable safe marathon preparation in athletes with T1D. Integrated continuous glucose monitoring and insulin pump therapy support adaptive insulin management during endurance training, while smartwatch-derived metrics support the training responses monitoring. Therefore, technology promotes personalized and telemedicine-oriented care models.