Interaction between impaired glucose control and sleep disturbances in elite athletes

Samband mellan försämrad blodsockerkontroll och sömnstörningar hos elitidrottare

Project Leader

  • Filip Larsen


  • Department of Physiology, Nutrition and Biomechanics

Research Funders

  • Swedish National Centre for Research in Sports


Below you can read summaries about the project in English and/or Swedish. The information is taken from the publication database DiVA.

It is well established that an appropriate exercise stimulus improves performance, whereas too much training leads to staleness and reduced performance. This state of impaired performance is termed non-functional overreaching (NFOR), which can develop into the overtraining syndrome. Athletes are advised to get more sleep time and improve the quality of sleep to improve recovery. Interestingly, it is well recognized that moderate levels of exercise increase sleep quality while excessive exercise for unknown reasons can cause sleep disturbances. NFOR is further associated with mood disturbances and an increased incidence of viral infections.

In previous and ongoing projects we have found that NFOR is associated with an unexpected shutdown of mitochondrial function that coincides with a disturbance in glucose metabolism. Likewise, we have found that elite endurance athletes have more episodes of both hyper- and hypoglycaemia than a matched control group. Nocturnal hypoglycaemia is associated with sympathetic activation and triggers an awakening response in healthy individuals and can thereby interact with sleep quality. Additionally, sleep deprivation causes depressed immune function and glucose intolerance in healthy subjects thereby highlighting the multidirectional relationship between NFOR, sleep disturbances, glucose regulation and immune function.

The present proposal is an observational study in a real-life setting following elite athletes in their normal training and competitions for one year. We will closely measure sleep, glucose control, mood, immune function, training load and athletic performance.

This project has 3 distinct objectives;
1) Does nocturnal blood glucose levels affect sleep patterns in elite athletes?
2) Can NFOR be detected at an early stage using continuous glucose monitoring, sleep tracking and subjective mood ratings?
3) Can we predict athletic performance by tracking training volume/intensity, nocturnal blood glucose, sleep patterns, immune function and mood state?

Using new technology, we can follow blood glucose, sleep pattern, training load, subjective well-being and athletic performance continuously in elite athletes in their natural environment with minimal interference. Our hypothesis is that we can detect NFOR at an early stage by signature changes in glucose metabolism and sleep patterns. If successful, this project can have a large impact on improving athletes training, health and athletic careers.

Träning på hög nivå brukar beskrivas som en balansgång mellan lagom hård träning och alltför hård träning som leder till sämre prestationsförmåga och ökar risken för infektioner, sömnstörningar och metabola rubbningar. I dagsläget saknas helt objektiva markörer som kan diagnosticera om en idrottare tränar för hårt. Den teknologiska utvecklingen har gjort att man nu kan mäta blodsocker kontinuerligt, sömncykler, puls, pulsvariabilitet och kroppstemperatur mäts med en enkel ring på fingret. Träningsintensitet övervakas med GPS och puls.

Syftet med detta projekt är att använda dessa nya tekniska hjälpmedel för att förstå vad som händer när idrottare tränar alltför hårt. Vi vill förstå hur sömn, immunförsvar och kroppen blodsockerkontroll förändras under perioder med alltför hård träning.

Funding period

  • 2021 - 2023

Project type

  • Project grant

National Research Field

  • Sport and Fitness Sciences