Obesity is a growing epidemic with almost two thirds of Australian adults classified as overweight or obese. Exercise is known to be beneficial as an intervention in obesity, possibly due to increases in mitochondrial activity and the concomitant increases in nicotinamide adenine dinucleotide (NAD+). Recent studies have tried to pharmacologically increase NAD+ levels through supplementation with precursors such as nicotinamide mononucleotide (NMN). Our previous work comparing effects of NMN and exercise in the context of high fat diet (HFD)-induced obesity showed that both interventions were able to improve glucose tolerance but were associated with differing tissue-specific effects on mitochondrial function. Here we aimed to examine whether NMN and exercise could synergise in the management of obesity. Eighty 5-week old female C57BL/6J mice were split across 5 groups: Control (Con), HFD, HFD with NMN (HN), HFD with exercise (HEx) and HFD with both NMN and exercise (HNEx). After 11 weeks of diet, the exercise groups started treadmill exercise (15m/min for 45 min, 6 days/week), while NMN groups received NMN in drinking water (400mg/kg body weight/day). These interventions continued for 8 weeks during which metabolic measures were performed before collection of tissues. As expected, HFD feeding increased body weight and adiposity, with no significant impact of any intervention. Interestingly while impaired glucose tolerance caused by HFD-feeding was improved in the HEx group, this was not observed in the HNMN nor the combination HNEx groups. Both NMN groups had significantly increased liver NAD+ levels. Muscle mitochondrial DNA (mtDNA) copy number was increased in both exercise groups compared to HFD group. Overall, these data suggest that although NMN was able to increase liver NAD+ and exercise was able to improve glucose tolerance and increase muscle mtDNA copy number, there was no evidence for synergistic benefits of NMN supplementation and exercise.