We just published a new paper in the Journal Nutrients that addresses the role of carbohydrate for team sports (and other intermittent activities). The paper is a review article summarizing all available literature and is published as Open Access which means that everyone can download it and read it. Click link to the full paper here.
The paper reviews:
(1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance
(2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition
(3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence.
I would refer the interested reader to the full paper, but here is a very brief summary:
There is some potential for carbohydrate ingestion to enhance performance in tests that simulate the intermittent high-intensity nature and skills of intermittent sports. Carbohydrate ingestion consistently improves intermittent high-intensity exercise capacity; however, studies have shown mixed results (some show improved and show minimal or no effect) with regards to effects on sprinting, skill and minimal effects on jumping and cognition (attention and response time).
Carbohydrate intake at a rate of 30–60 g/h has been associated with a consistent beneficial effect on skill performance in soccer. On the other hand, studies in basketball and racquet sports have found mixed results (at best) from 35–80 g/h carbohydrate ingestion on sport-specific skills.
In most of these studies the amount of carbohydrate consumed was 30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin.
It is my personal opinion that this field of research would benefit from better validated studies where the day to day variation of specific tests are known before embarking on performance tests. If the day to day variation is large, it will be very difficult to pick up small but relevant changes in performance. Without knowing the variation that naturally occurs, it is difficult to judge whether a test shows no effect because there is too much “noise” in the measurement or because there really is no effect. This is especially important because these studies are not easy to perform and the number of subjects is typically small.
Based on the information available it is certainly advisable to make sure there is adequate carbohydrate supply, but I would encourage everyone with a passion in this area to study this further so we get more well controlled studies that will help us to refine the guidelines for athletes involved in intermittent sports.
Lindsay B. Baker, Ian Rollo, Kimberly W. Stein and Asker E. Jeukendrup Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance. Nutrients 2015, 7, 5733-5763; doi:10.3390/nu7075249