Effects of age, sex, disease, and exercise training on lip muscle strength

Abstract

Lip muscle strength has been shown to influence daily functional activities such as facial expression, speech production, and eating. In this review, recent literature regarding lip strength and exercise training responses are summarized, highlighting the influence of sex, age, and disease (e.g., stroke). A search using five electronic databases was conducted. Twelve studies were identified from the search, which included five studies using healthy adults and seven studies using patients with diseases or chronic ailments. Regardless of the population, lip strength training multiple times a day for a relatively short term (<24 weeks) has resulted in improvements of lip muscle strength. This change in lip strength has been observed in both young and old participants. Although changes in strength have been observed in both men and women, we are unaware of any studies that have tested whether there are sex differences in this response. The same directional change can be expected for patients with stroke and patients with lip incompetence, but the magnitude of the training effect seems to be higher in healthy people.