Tongue-Strengthening Exercises in Healthy Older Adults: Effect of Exercise Frequency - A Randomized Trial

Introduction: Positive effects from tongue-strengthening exercises (TSE) are widely described, but dose-dependent studies concerning exercise frequency have not yet been reported. This study aimed to determine the training and detraining effects of TSE with exercise frequencies of respectively 3 and 5 times per week on maximum isometric anterior and posterior tongue pressures (MIPA and MIPP) and on anterior and posterior tongue strength during an effortful saliva swallow (Pswal(A) and Pswal(P)). Method: Twenty healthy adults were randomly assigned to two exercise groups, training 3 (EX3, n = 10) or 5 (EX5, n = 10) times per week with the Iowa Oral Performance Instrument. MIPA, MIPP, Pswal(A), and Pswal(P) were measured at baseline, after 4 and 8 weeks of training and 4 and 8 weeks after the last training session to document detraining effects. Descriptive statistics, linear mixed model effects, and post hoc analyses were calculated. Results: Significant increases in MIPA, MIPP, Pswal(A), and Pswal(P) were measured for training both 3 and 5 times per week. No significant differences on any parameter were found between EX3 and EX5 groups. No significant detraining effects were found after 4 or 8 weeks in any treatment arm either for MIPs or for effortful swallow pressures. Conclusion: This randomized study demonstrated a positive effect of TSE on MIP and Pswal in healthy older adults, without detraining effects. No superiority of exercise frequency was identified based on significance testing, although some trends are discussed.