Nitrate and Exercise Performance in Middle to Older Aged Adults
Condition: Aging
Study type: Interventional

Summary: 
      Research with young healthy individuals has shown that beetroot juice beverages that contain
      large amounts of nitrate can improve exercise performance. Currently, it is not know whether
      the consumption of beetroot juice beverages high in nitrate can improve exercise performance
      in higher functioning middle- to older-aged adults. Therefore, the purpose of this study is
      to compare the effect of two different beetroot juice beverages (one high in nitrate and one
      low in nitrate) on exercise performance in middle- to older-aged adults.
    

Detailed description: 
      Nitric oxide (NO) has been identified as an important biological messenger involved in a
      number of physiological processes and is produced from L-arginine and molecular oxygen by
      NO-synthases or the more recently identified nitrate to nitrite to NO pathway. Dietary
      nitrate can be found in green leafy vegetables and is particularly abundant in beetroot and
      has been shown to be a potential ergogenic agent. The nitrate to nitrite to NO pathway has
      been shown to be involved in a number of physiological processes that could account for the
      improved exercise response following nitrate ingestion. However, the benefits of nitrate as
      an ergogenic aid have been shown to be effected by numerous factors that can influence its
      efficacy. These include age, training level, dosage and the mode, duration and intensity of
      the exercise.

      Research with healthy younger moderately trained adults has repeatedly shown that ingestion
      of dietary nitrate can reduce the oxygen cost of submaximal exercise and improve exercise
      performance during high intensity exercise; whereas research with younger more highly trained
      endurance athletes is equivocal, since some studies have failed to demonstrate an improvement
      in exercise performance following nitrate ingestion.

      The effects of nitrate have also been shown to be influenced by age. It has been documented
      that there are alterations in NO metabolism in older adults thought to result from impairment
      of the NO-synthases pathway. The investigators have shown that consumption of a supplement
      high in nitrate, such as beetroot juice, leads to elevated plasma nitrite levels and may help
      restore NO metabolism in older adults; whereas a diet high in nitrate without supplementation
      was insufficient at increasing plasma nitrite levels. The investigators research, along with
      that of others has shown nitrate supplementation to have positive effects in older adults
      with chronic diseases. However, research examining the effects of dietary nitrate on exercise
      performance in healthy older adults is scarce. Presently, it is unclear as to whether nitrate
      supplementation is beneficial to exercise performance in older adults and there is no data
      examining the effect of nitrate supplementation on exercise performance in active older
      adults. Therefore, the purpose of this study is to examine the effect of chronic nitrate
      supplementation on exercise performance in active higher functioning older adults.
    

Intervention name(s): High Nitrate Beetroot Juice; Low Nitrate Beetroot Juice
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): High nitrate beetroot juice (120 ml) will be administered for 7 days consecutively followed by a 7 day washout period then 7 consecutive days of low nitrate beetroot juice.; Low nitrate beetroot juice (120 ml) will be administered for 7 days consecutively followed by a 7 day washout period then 7 consecutive days of high nitrate beetroot juice..
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Beetroot Juice; Older Adults; Nitrate; Nitrite; Nitric Oxide