A Cochrane review included 13 studies with a total of 106 subjects. The largest treatment trial included 19 cases. As there were only single trials for a given intervention no meta-analysis was undertaken. There is a lack of evidence to show benefit from supplementation with branched chain amino acids, depot glucagon, dantrolene sodium, verapamil, vitamin B6, high dose oral ribose or high dose creatine. Minimal benefit was found with low dose creatine and ramipril only for patients with a polymorphism known as the D/D angiotensin converting enzyme (ACE) phenotype. A carbohydrate-rich diet resulted in better exercise performance compared with a protein-rich diet. Two studies of oral sucrose given at different times and in different amounts before exercise showed an improvement in exercise performance.
Comment: The quality of evidence is downgraded by imprecise results (few patients and wide confidence intervals), by inconsistency (heterogeneity in interventions and outcomes) and study quality (inadequate allocation concealment).