A series of phenylglyoxylic acids is described, many of which are able to promote carbohydrate oxidation in muscle tissue, thereby favorably altering the carbohydrate/fatty acid balance in situations where fatty acid utilization is elevated. Such situations are reported to occur in ischemic heart disease, particularly following myocardial infection. In an attempt to effectively deliver the phenylglyoxylic acids to the site of action within the cell, the L-(+)-phenylglycines were employed as prodrugs. These are known to be transaminated to phenylglyoxylic acids. L-(+)-2-(4-Hydroxyphenyl)glycine (25, oxfenicine) has been selected for clinical evaluation.