Carbohydrate supplementation stabilises plasma sodium during training with high intensity

authored by

M. Schrader, B. Treff, T. Sandholtet, Norbert Maassen, V. Shushakov, J. Kaesebieter, Mirja Maassen

Abstract

Background: Investigations of the effect of beverages containing carbohydrates, only, on the sodium and fluid balance during intermittent exercise of high intensity are rare. Therefore, we compared the effects of water and carbohydrate supplementation on plasma, blood volume, and electrolyte shifts during intermittent exercise. Methods: Ten male subjects performed an intermittent exercise test twice. In one trial, tap water (4 ml/kg/15 min) was consumed (Plac trial). In the other trial, the same amount of water supplemented with maltodextrin to achieve a 9.1 % carbohydrate solution (CHO trial) was ingested. Training schedule: warm-up at 50 % for 15 min. Afterwards, power changed between 100 % of the maximum power from a previous incremental test minus 10 and 10 W for each 30 s. Venous blood was sampled to measure electrolytes, osmolality, [protein], hct, [Lactate], [glucose], [Hb] and catecholamines. Hydration status was evaluated by BIA before and after exercise. Results: After beverage ingestion [glucose] was significantly higher in CHO until the end of the trial. Starting with similar resting values, osmolality increased significantly more during CHO (p = 0.002). PV decreased by 5 % under both conditions, but recovered partly during exercise under Plac (p = 0.002). [Na+] and [Cl⁻] decreased with Plac during exercise (both p < 0.001) but remained constant during exercise with CHO. Conclusions: Sole carbohydrate supplementation seems to stabilise plasma [Na+]. This cannot be explained simply by a cotransport of glucose and [Na+], because that should lead to a recovery of the blood and plasma volume under CHO. In contrast, this was found during exercise with Plac.

Organisation(s)

Institute of Sports Science

External Organisation(s)

Hannover Medical School (MHH)
Data Input

Type

Article

Journal

European Journal of Applied Physiology

Volume

116

Pages

1841-1853

No. of pages

13

ISSN

1439-6319

Publication date

01.09.2016

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Orthopedics and Sports Medicine, Public Health, Environmental and Occupational Health, Physiology (medical)

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1007/s00421-016-3429-4 (Access: Closed)