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Beet juice vs. nitrate supplements

October 3rd, 2011

The story so far: beet juice improves endurance performance. We’re pretty sure it’s because of the nitrate in beets. But we’re not sure whether you can get the same effects by simply taking nitrate supplements directly.

Enter a study in this month’s Medicine & Science in Sports & Exercise, from researchers  in Spain. They administered either a placebo or a dose of sodium nitrate (10 mg per kg of body weight) to 11 well-trained cyclists and triathletes. Then, three hours later, the athletes did a series of sub-maximal cycling bouts and a progressive VO2max test to exhaustion. The results: well, this is where it gets confusing:

[W]e found that the VO2peak was significantly reduced when athletes ingested nitrate. These in vivo data were found without any changes in cardiorespiratory and performance parameters, which suggests that nitrate and its reaction products could play an important role in oxygen consumption at maximal intensity of exercise in well-trained athletes.

So basically, in the progressive test to exhaustion, the athletes lasted the same amount of time with or without nitrate (416 seconds with nitrate, 409 seconds with placebo, a nonsignificant difference) — but they reached failure while using less oxygen. So the good news is that nitrate did somehow make the cyclists more efficient at converting oxygen into power. But the bad news is that this didn’t improve their performance — they just used less oxygen.

What to make of this? I’m not sure. That’s partly because the paper is fairly confusing, but I think it’s also because researchers simply don’t know what exactly is going on yet! For practical purposes, my conclusion would be that if you’re looking for a boost, stick with real beet juice rather than sodium nitrate for now. There may be other differences between this study and previous successful performance-boosting studies (e.g. in the training of the subjects, their typical dietary habits and usual nitrate levels, etc.) — but until further studies sort this out, the only thing we know for sure is that beet juice, in some circumstances, works.

  1. David Bailey
    October 3rd, 2011 at 21:43 | #1

    This response is thought to be related to the reduction in blood pressure from nitrate and the subsequent reduction in cardiac pre-load, ventricular pressure and hence stroke volume. However, that is not always seen, so it’s likely this is mode, protocol and perhaps person specific.

  2. RH
    October 4th, 2011 at 07:04 | #2

    Probably no simple answers here, but let’s give it a try.

    The difference between this study and the other you blogged about seems to be that in this study they performed a pretty tough time to exhaustion trial (exhaustion in six minutes), while in the other study the subjects performed a self paced time trial.

    If nitrate makes you use oxygen more efficiently, it seems plausible that you can exploit this best in a self paced time trial, where you can ‘play’ with your oxygen debt, rather than in a short all out effort.

    Secondly I presume that is difficult to get significant results from a graded +_ six minute test, since the individual variation will likely drown the effect of the intervention, especially if, as I assume to be the case, it starts out easy, so the difference is made in just the last few minutes.

  3. alex
    October 4th, 2011 at 12:59 | #3

    @RH: This explanation makes sense to me. I guess it implies (as other studies have done) that supply of oxygen is NOT the limiting factor at VO2max pace — thus, when an intervention causes you to use oxygen more efficiently, you reach the same limits (whatever they are) but use less oxygen.

    It’ll be nice to see (a) a VO2max-style test using beet juice, and (b) a time-trial study with sodium nitrate, to confirm this.

  4. October 4th, 2011 at 14:13 | #4

    Could this finding be useful for sea-level athletes competing at altitude, when they’d want to be using a lower level of oxygen very efficiently?

  5. dave
    October 4th, 2011 at 14:26 | #5

    we are currently investigating this issue in our laboratory. So far, the results are inconclusive.

  6. thescience
    June 20th, 2013 at 23:14 | #6

    I get huge advantages from megadosing spinach powder, but this is for high intensity weight lifting. ive noticed no advantage running. I bought spinach designed for this purpose and it has an VERY pronounced muscle hardening effect and the quality of my reps has improved. that said, that amount of spinach, equal to 180 grams of fresh spinach I supposed (though nitrate content may vary) is hard to tolerate. for that reason, I will be trying sodium nitrate. interestingly, the reason why the spinach works is beause two proteins are increased pertaining to calcium regulation, leading to better muscle contraction. as I get way more calcium than most people (from protein shakes, milk and spinach) I believe this heightens the effect. sodium nitrate is in the mail. drop a comment if anyone wants to hear how that goes

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