Dietary nitrate markedly improves voluntary running in mice

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry

Background:

• Nitrate supplementation is known to enhance submaximal force in skeletal muscles.
• The impact of nitrate on voluntary running performance and underlying physiological adaptations requires further investigation.

Purpose of the Study:

• To determine if nitrate supplementation improves submaximal voluntary running performance in mice.
• To investigate the effects of nitrate on endurance, mitochondrial function, and running capacity.

Main Methods:

• Male C57Bl/6N mice were administered nitrate in drinking water.
• Mice were housed with or without access to an in-cage running wheel for varying durations.
• Running performance, endurance capacity (treadmill test), and mitochondrial citrate synthase activity were assessed.

Main Results:

• Nitrate supplementation significantly increased running speed (20%) and distance (30%) in mice with access to a running wheel.
• Endurance capacity improved by approximately 13% on a treadmill test, accompanied by a 14% increase in citrate synthase activity.
• Running performance decreased to control levels when nitrate supplementation was withdrawn.

Conclusions:

• Nitrate supplementation facilitates submaximal exercise, such as voluntary running, by improving low-frequency force.
• Enhanced mitochondrial oxidative capacity and exercise performance are dependent on continued nitrate intake.