Fig. 1

Flow diagram of article selection process. ¹ Exclusion of duplicates. ² not randomized controlled trials, different age group, no time trial or submaximal exercise followed by time trial. ³ Considerable differences with respect to type of exercise: McGawley et al., [29]; Rollo et al., [28]. Soccer-specific protocol: Clarke et al., [30]. Considerable differences with respect to carbohydrate intervention: Burke et al., [25]; Burke et al., [26]; Beelen et al., [27]. Inoperable presentation of data: El-Sayed et al., [33]; Flynn et al., [32]