Background and Aims: People with type 1 diabetes (T1D) experience higher rates of sleep disturbances than those without diabetes, and this can have negative implications for glycemic control. Sleep is critical for optimal athletic performance and recovery so it is important to have an understanding of factors that can influence sleep in athletes with T1D. This study investigated whether there is a relationship between i) daily training load and ii) time in glycemic ranges on sleep time of professional cyclists with T1D.

Methods: Sixteen professional cyclists from Team Novo Nordisk (age 27 ± 4 y; HbA1c 6.8 ± 0.5%) used a wrist-worn actigraph device (Actiwatch Spectrum Plus, Philips Respironics, Murrysville, PA) to monitor sleep-wake activity over a 10-day training camp. Training variables (distance (km), elevation (m), work (kJ)) were used to determine a training stress score (TSS) for each day of the camp and glycemia was recorded using Dexcom, G6 (San Diego, CA). Summary statistics and correlations were run over the measured variables.

Results: On average, riders spent 8.6 ± 1 h in bed with a total sleep time of 7 ± 1.3 h (6.0 ÷ 7.8). The riders cycled 115 ± 26 km with 1849 ± 1086 m of elevation gain per day, corresponding to a mean TSS of 221 ± 142. Total sleep time was negatively associated with TSS (-0.29, p=0.01). Greater time in range (4-10 mmol/l) was positively associated with sleep time (r=0.21, p=0.03), with hyperglycemia, particularly level 2 (>14 mmol/l), being negatively associated with sleep time (-0.21, p=0.03).

Conclusions: We provide preliminary evidence that a greater TSS is negatively associated with total sleep time in professional athletes with T1D. Second, greater time spent in euglycemia is associated with greater sleep time, with time above target having a negative association with sleep. Further data should be collected longitudinally to strengthen these results to serve as a basis to promote better sleep hygiene practices to overcome the effects of higher training loads.


S.N. Scott: None. F.Y. Fontana: None. B. Martinez-Gonzalez: None. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. P.H. Lagrou: None. S. Marcora: None. T. Zueger: None. C. Stettler: None.

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