The effects of pre-exercise blood glucose on responses to short duration high intensity exercise

Swanwick, E; Matthews, MJ

Abstract

Purpose
To investigate the relationship between pre-exercise blood glucose levels and performance during a 7-point incremental swim test.

Methods

Forty-two National level swimmers undertook a 6 × 200 m incremental training set at predetermined pace, followed by an additional maximum effort swim, with each swim starting every 6:30 minutes. Subjects were asked to be one hour post-absorptive. Results were analysed in three groups based on pre-test blood glucose level; Low Blood Glucose (LBG) below 4.3; Euglycemic (EUG), 4.3 mmo/l to 6.0 mmol/l; High Blood Glucose (HBG) above 6.0 mmol/l. After each 200 m - swim, blood glucose, blood lactate, and heart rate were taken. Additionally, swim speed, stroke count, and stroke rate were recorded for each swim. Values were plotted against the swim time of each swim.

Results

Significant differences were observed between responses for both LBG and HBG when compared to EUG for blood glucose, lactate and heart rate (P < 0.01). Additionally, markers of swim efficiency and swim speeds were significantly affected by LBG (P < 0.01). High blood glucose appeared to be beneficial to swimming efficiency against LBG and EUG (p < 0.01).

Conclusions

Blood glucose levels prior to swimming had a marked effect on performance. LBG resulted in a significant reduction in the blood glucose, lactate, heart rate, and swimming efficiency responses to swimming at a range of intensities, up to maximal effort.

Citation

Swanwick, E., & Matthews, M. (2018). The effects of pre-exercise blood glucose on responses to short duration high intensity exercise. International journal of sports and exercise medicine, 4(1), https://doi.org/10.23937/2469-5718/1510082

• Journal Article Type: Article
• Acceptance Date: Jan 6, 2018
• Online Publication Date: Jan 8, 2018
• Publication Date: Jan 8, 2018
• Deposit Date: Apr 6, 2018
• Publicly Available Date: Apr 6, 2018
• Journal: International Journal of Sports and Exercise Medecine
• Volume: 4
• Issue: 1
• DOI: https://doi.org/10.23937/2469-5718/1510082
• Publisher URL: http://dx.doi.org/10.23937/2469-5718/1510082
• Related Public URLs: https://clinmedjournals.org/International-Journal-of-Sports-and-Exercise-Medicine.php