The other change is I'm going to give the Beet Shot Pro (Concentrated Beet Juice) a try. I was having a conversation with another DIS user about the effects of Beet Juice on endurance performance and whether the scientific research supported the idea. This is what I surmised from the research:
Conclusions
-Acute supplementation (one time) with beetroot juice may have an ergogenic effect on reducing VO2 at less than or equal to VO2max intensity, while improving the relationship between watts required and VO2 level, mechanisms that make it possible to enable increase time-to-exhaustion at less than or equal to VO2max intensity.
-In addition to improving efficiency and performance in various time trials or increasing time-to-exhaustion at submaximal intensities, chronic supplementation with beetroot juice may improve cardiorespiratory performance at the anaerobic threshold and VO2max intensities.
-Apparently, the effects of supplementation with beetroot juice might not have a positive interaction with caffeine supplementation, mitigating the effects of beetroot juice intake on cardiorespiratory performance, however, more work is needed to confirm the results of these investigations because the number of studies analyzing the effects of the combination of beetroot juice with other supplements, such as caffeine, is limited.
-Intake of beetroot juice should be initiated within 90 min before athletic effort, since the peak value of NO3 occurs within 2–3 h after ingestion. At least 6–8 mmol (400mg) of NO3 intake is required, which can be increased in athletes with a high level of training.
-Can't use mouthwash because it destroys the necessary type of bacteria in the mouth. The reason the Beet Juice works is because it increases the amount of NO3 and that occurs because of the breakdown of the Beet Juice by the bacteria as it is being swallowed. I also read that you shouldn't chew gum either.
What's interesting to me is the research is based on two time frames: Acute (one time) and Chronic (6 days). The 6 day data seems to suggest additional benefits above and beyond the acute dosing. It does appear the benefits are about 1-2% in racing times.
For a 24 min 5k, that's 23:31-23:46 just by taking beet root supplementation. A 1:50 HM, would be a 1:47-1:48 by supplement. A 3:04 M, would be a 3:00:19-3:02:10 by supplement. So while, 1-2% seems small it might be just enough extra push to reach a goal (say a 3:04 marathoner's goal of a 2:59 marathon perhaps...)
The source that was tested continuously was from
http://beet-it.us/where-to-buy/
Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Raul Dominguez
This is pharmacodynamic and dose response data based on a single dose.
Beetroot juice and exercise: pharmacodynamic and dose-response relationships. Lee J Wylie.
So this data shows that the timing of the dose matters as far as nitric oxide concentration goes (only this specifically as other gains like blood pressure and mitochondrial changes very well can be a cumulative effect). It shows that the peak of the beet root juice and cardiovascular/VO2max improvements occurs around 2.5-4 hours. If you take it as a night time dose and run in the morning (~12 hrs later), then there will be a small gain over water, but not much. The 24 hr timepoint shows that unless the dose is really high the effects of nitric oxide wear off after 24 hrs. That's where my dose lives is in the higher range. Which means after 24 hrs a small residual is left over. As each successive day passes, there will be more and more residual remaining. Now this is a presumption based off a single does. To confirm we would need a baseline value from a single dose (like above) and then a second pharmacodynamic curve after 6 doses (not done by this paper). That should show the "0" as higher than the baseline "0". In the end, my belief is that there is a certain threshold based on an individual's characteristics that must be passed in order to elicit the benefits. The unknown is where is each person's threshold. But since no negative effects were seen at the higher dosage for 6 days, then I might as well go for that under the assumption my necessary threshold will be below that level. The accumulation will help increase the overall dose load over time.
Well the initial caffeine and beetroot juice research seems to imply they don't have an additive effect. One or the other is sufficient in receiving similar benefits.
Another paper seemed to suggest that the time trial benefits is reduced for people with a higher VO2max. Other research contends a higher dose is necessary for those with a higher VO2max.
The really difficult part about the research out there is that everyone seems to be using various dose levels, or various timing on dosing. Based on the pharmacodynamics, it would appear that timing of the dose is critical as well as the amount taken to maximize the effects.
This is like mid-January! I'm starting week 5 of my May HM plan today and I'm ready to run in some nicer weather. 
