Effects of nicotinamide mononucleotide and paprika xanthophyll on endurance performance: a randomized, placebo-controlled, double-blind, parallel group study

Efficient energy production is essential for endurance performance, and thus it is important to promote mitochondrial ATP production. Nicotinamide mononucleotide (NMN) is converted to the coenzyme nicotinamide adenine dinucleotide (NAD+), which contributes to mitochondrial ATP production. Meanwhile, paprika xanthophyll (PX), an oil-based extract from ripe red paprika, improves the oxygen-delivery capacity of red blood cells by increasing their membrane flexibility. This study was a randomized, placebo-controlled, double-blind, parallel-group trial that investigated the effects of intake of NMN (500 mg/day), PX (9 mg/day), or their combination for 8 weeks on endurance performance. The participants were male collegiate track-and-field athletes aged 18 years or older. As endurance performance, running velocity at lactate threshold, running velocity at the onset of blood lactate accumulation, and heart rate were evaluated using the lactate curve test. The results showed that NMN did not effectively improve endurance performance after intake for 8 weeks, which was the primary endpoint of this study. However, the results after intake for 4 weeks, as well as stratified analyses by blood NAD+ levels before intake, suggested that the combination of NMN and PX might improve endurance performance. Thus, both the increase in NAD+ induced by NMN intake and sufficient oxygen delivery induced by PX intake may be beneficial for promoting mitochondrial ATP production, thereby leading to improved endurance performance.