Dietary nitrate, L-citrulline, epicatechin, vitamin C and glutathione have the potential to improve nitric oxide (NO) bioavailability, in humans, by influencing both the nitrate-nitrite-NO and NO synthase-dependent pathways, and the storage of NO. The study is designed to assess the efficacy of a newly developed product containing a mixture of these compounds. Specifically, the study will assess if the product is capable of increasing NO bioavailability and if this results in positive effects on exercise economy and intermittent exercise performance. These outcome measures have been chosen because they have previously been positively impacted by an increase in NO bioavailability.

Inclusion Criteria:

1. Male and female participants in self-reported good general health as assessed by the standard procedures described below and specifically meeting the following blood pressure (BP) and body mass index (BMI) ranges: systolic BP: 100-140 mmHg; diastolic BP: 60-90 mmHg; and BMI 18.5-30.
2. 18-40 years of age
3. Physically active. Determined by meeting the following criteria: completes vigorous physical activity (i.e. activities that take hard physical effort and make you breathe much harder than normal; e.g. heavy lifting, digging, aerobics, fast cycling, running etc) at least 2 x per week and moderate physical activities (i.e. activities that take moderate physical effort and make you breath somewhat harder than normal; for example: carrying light loads, cycling at a regular pace, playing doubles tennis) at least 3 x per week.
4. Understanding of the procedures to be undertaken as part of the study
5. Willingness to participate in exercise testing and follow supplementation guidelines and other instructions provided by the experimenter
6. Informed, voluntary, written consent to participate in the study

Exclusion Criteria:

1. Known pulmonary, cardiovascular or metabolic disease
2. Food allergies including phenylketonurea (PKU)
3. Current regular use of any dietary supplement (excluding macronutrient based supplements) or previous use of any dietary supplement in the past 6 months that is known to have a lasting effect.
4. Blood donation within 3 months prior to the start of the study
5. Substance abuse within 2 years of the start of the study
6. Smoking
7. Any prescription and non-prescription medication which may impact saliva production (antidepressants, diuretics, analgesics, antihistamines, anti-hyper/hypo-tensives, anti-anxiety, appetite suppressants).
8. Current or previous use of phosphodiesterase 5 (PDE5) inhibitors.
9. Participation in another clinical trial within past 4 weeks.
10. Participation in another PepsiCo study within the past 6 months.
11. Highly trained or elite endurance athlete as determined by current or recent (within 3 months) participation in an endurance sport at international or national level.
12. Pregnancy