Correction: A randomized controlled trial of nitrate supplementation in well-trained middle and older-aged adults

• Michael J. Berry, 
• Gary D. Miller, 
• Daniel B. Kim-Shapiro, 
• Macie S. Fletcher, 
• Caleb G. Jones, 
• Zachary D. Gauthier, 
• Summer L. Collins, 
• Swati Basu, 
• Timothy M. Heinrich