comparison of low-intensity and high-intensity exercise in salivary nitric oxide response: a pilot study

Background: excessive production of salivary nitric oxide (s-no) is a risk factor for oral diseases such as sjogren syndrome and periodontal disease. although s-no is known to be affected by exercise, it is unclear how the difference in exercise intensities affects the s-no response. objectives: the purpose of this study was to investigate the acute effect of different exercise intensities (high vs. low intensity) on s-no production using a cross-over design. methods: five healthy male young adults (21.6 ± 0.9 years) performed two ergometer exercises for 30 min at different exercise intensities: 50% heart rate (hr)reserve (low-intensity condition) and 80% hrreserve (high-intensity condition). saliva samples were collected before (pre) and after (post 0-h and post 1-h) exercises. results: the s-no concentration significantly increased (p < 0.05) after the high-intensity exercise (δchanges in post 0-h; +244 ± 53μmol/l, post 1-h; +352 ± 58μmol/l), but the s-no concentration did not change after the low-intensity exercise (δchanges in post 0-h; +11 ± 37 μmol/l, post 1-h; +64 ± 69 μmol/l). conclusions: this study reveals that s-no production is dependent on exercise intensities, suggesting that low-intensity exercise can be possible without increasing the risk of oral diseases.