Objective: Standardized performance assessments are routinely used in Exercise Science to 1) measure muscle capacity and 2) monitor metabolic adaptations and response to intervention for both cardiovascular (aerobic) and muscle strength/power (anaerobic) performance. Clinically a standard voice evaluation is typically limited to sustained phonation, pitch glides, and brief reading passages for acoustic and aerodynamic analysis. Ecologically valid measures to assess vocal metabolic fitness /capacity in occupational voice users has yet to be established. The investigation sought to explore the validity of a newly adapted vocal fitness task to measure anaerobic vocal capacity by determining the association between a gold standard anaerobic power assessment used in Exercise Science and vocal function measures developed from the vocal fitness task.

Methods: A prospective study of 44 participants (age range 21-38 years, 26 females and 18 males) was completed. During the pretrial visit, participants were consented, trained in an adapted 60 second laryngeal diadochokinesis (LDDK) task, and acoustic and aerodynamic data was collected. At the trial visit body composition analysis was conducted and participants completed the LDDK task as well as the Wingate Cycling Test, a gold standard anaerobic power assessment routinely used in Exercise Science.

Results: Correlation analyses indicated a positive relationship between rate of the LDDK task that was produced at a high frequency/high sound level and mean anaerobic power. Results also indicated a negative relationship between the number of breaths produced during the LDDK task and mean anaerobic power. A multiple linear regression analysis revealed that the combined relationship between forced vital capacity and mean anaerobic power predicted the LDDK rate.

Conclusions: These results support previously found preliminary data on the LDDK being a potentially sound and clinically useful vocal fitness assessment to measure vocal anaerobic (power) ability. The LDDK task may also be used as an outcome measure to determine the metabolic adaptations and mechanistic changes that occur because of voice therapy. This would allow future work to create more individualized therapies to target the unique needs of voice disordered populations of varying metabolic profiles. Furthermore, an individual’s anaerobic capacity may be associated with / inform individual physiological processes used to produce voice.