Andy Jones Interview (Transcript)
1. Andy, you are a Professor of Applied Physiology and Associate Dean Research at the University of Exeter – where did an Exercise and Sport Science passion start for you?
I think my interest probably began as an athlete myself – as a teenager I was reasonably successful as a distance runner and I wanted to learn more about the limits of performance and so I was naturally drawn to Sports Science. I did my first degree in Sports Science and eventually my PHD in Exercise Physiology and as my running career started to fall by the way side then I was able to put that same energy into studying the limitations to performance and so it was a natural sort of transition.
2. In your career you've worked with Elite athletes such as Paula Radcliffe. What other interests in sport do you have?
I guess I'm a fan of all sports really; I love it when the Olympics comes around. I'm a fan of rugby, particularly, as a Welshman I follow the 6 Nations very closely. But I think my first love will always be endurance sports but distance running in particular. With my background as a runner myself, I think that's the one that I continue to live vicariously through.
3. Many people know you as "@AndyBeetroot" online – such as Twitter – why was beetroot the chosen vegetable?
Nitrate is contained in a variety of different vegetables; green leafy vegetables in particular, and a couple of fruits as well. We chose beetroot simply because it's quite easy to administer because you can juice beetroot – and it's very easy to consume in a liquid form – at certain volume, which contains a certain amount of nitrate – and when you're doing controlled laboratory experiments, that's quite a nice capability to have. Whereas with something like lettuce or spinach, you wouldn't ever quite know how much you were giving and to consume 100g of spinach prior to exercise is not quite so straight forward as consuming say, 70ml of beetroot juice.
4. Beetroot is available in many forms, why do you use concentrated beetroot shots rather than beetroot juice or the beetroot just the vegetable, for your research?
Beetroot is available in many forms and of course if you were to consume say three or four beetroots you’d consume a certain amount of nitrate, which would be effective. But the problem is, you don’t really know exactly how much you’re going to get. So it’s much easier to consume a liquid than a solid – especially if you’re an athlete and you’re due to train or to compete. And of course the smaller the volume of fluid that you consume, the more convenient that is as well so using the concentrated shots we find is more palatable and easier, just logistically both for us and for our subjects than consuming the 500ml of juice that we did in our original experiments.
5. What are the main physiological outcomes of consuming natural nitrate for sports performance?
Following the consumption of inorganic nitrate, there are a whole variety of physiological effects. One of the most striking is a reduction in the oxygen cost of exercise, which suggests that muscle has become more economical, or more efficient. Exactly why that occurs we’re not absolutely sure – it seems that the contractile apparatus in the muscle may become more efficient in itself. It may be that the mitochondria that produce energy aerobically become more efficient and simultaneously we think there’s a dilation of blood vessels to allow more blood and more oxygen to flow to the areas within the muscles that need it the most. So all that’s, I think quite important. And of course, if you can improve muscle economy, then you ought to be able to improve performance. More recently we find that actual muscle power output might be positively impacted as well which means that sprint sports and intermittent sports may benefit from nitrate consumption pre-exercise also.
6. Do the physiological mechanisms differ with different durations or different types of sport? For example, with a 10km cycle versus high-intensity intermittent running such as rugby or hockey?
So the mechanisms that may explain differences in physiological response and performance outcome in different types of sport probably vary according to the intensity and duration of exercise that we do. So for longer duration exercise, which predominantly relies on aerobic metabolism, then delivering plenty of oxygen to the muscles and using that oxygen very efficiently is what’s going to be important for performance. But if we’re talking about high power sports; short duration; sprint activities; intermittent sports such as rugby, soccer, hockey and so forth, then the effects on muscle contractility is what’s important as well and we think that there is some effect on calcium activity within cells which enables a stronger contraction.
7. Is there an optimal dose and duration of taking nitrate supplementation? And is there a maximal threshold for which you can consume?
We’re still investing the optimal duration of dosing and the optimal amount of nitrate that could be taken pre-exercise. Partly depends upon things such as body size and body mass and the type of activity that you may be performing. Generally speaking to take the nitrate for several days before competition, plus on the day of competition is what we’d recommend. And around 6 to 8 millimoles in one to two concentrated beetroot shots again is what we’d typically recommend. That would be taking two to three hours before the main competition because it takes about that long for the nitrate to be processed within the body. Any less than around 5 or 6 millimoles of nitrate possibly isn’t going to be very effective, unless you take it over a number of days consecutively, but any more than 8 to 12 doesn’t seem to have any extra benefit, so there is no advantage to taking more than the one or two shots per day or immediately prior to competition.
8. The majority of the research has looked at the effects of nitrate for exercise performance but is there any research that leads to the effects of natural nitrates for exercise recovery?
Most of our work has looked at the effects of nitrate pre-exercise, but there is some literature now looking at what happens post-exercise – in other words, recovery from exercise. And there’s some indications that it may be beneficial there as well. Now that could be because we get some dilation of blood vessels which enables oxygen to continue to flow and for waste products to be removed, but equally it seems that muscle damage which can occur following an unaccustomed bout of exercise is less pronounced when beetroot juice is consumed within that immediate recovery period. It may not be the nitrate actually because of course beetroot juice contains a whole variety of other components as well including polyphenols and antioxidants and flavonols and such alike, but it could be the ‘cocktail’ within the beetroot juice that’s important, more than – or as much as – the nitrate per-se.
9. Beetroot juice has been used to see the effects on sports performance in a variety of sports. So in a perfect world, what athlete, or what sport type would you love to get in the lab and experiment?
Beetroot juice has been used in a variety of different sports, different levels of competition, mostly with positive results. I think the area that we’re moving into now is the effect on sprint performance and muscle power and so forth, and there are some indications, at least in recreational or sub-elite athletes that it can be effective in those circumstances. What we don’t know yet is whether elite sprinters stand to benefit and I think that may be the next area to look at – elite basketball players who very much rely on power, elite football players, and sprinters themselves.
10. Given the range of sports and exercise types for using dietary nitrate on sports performance covers quite a large range now, is it safe to say that any athlete regardless of their discipline, could get a benefit from using natural nitrate supplementation?
I think athletes respond in different ways to different supplements – nutritional supplements – and that includes beetroot juice. We know that recreational athletes do tend to benefit on average; the elite athletes, possibly somewhat less so, at least at standard doses. I know a variety of reasons why that may be the case. So the higher aerobic fitness tends to reduce the impact that nitrate may have on performance. Even a small effect could be beneficial and sometimes small amounts are difficult to measure because of the variability that we get from day to day anyway. But we also see that in some elite athletes, that they do respond – like with lots of nutritional supplements – we have ‘responders’ and ‘non-responders’ and even in elite athletes there’s a small minority of athletes that still do benefit substantially, so probably worth them at least exploring the potential benefits of nitrate to their performance.
11. A lot of the research has been done on short – 30 to 40 minutes of exercise performance – with dietary nitrate. Is there any evidence to say that it could be beneficial for ultra-endurance athletes, say to use during as a top up?
Most of the research to date has focused on relatively short durations of exercise, whether they be continuous or intermittent. And an unanswered question at the moment is the extent to which it might also benefit much longer duration performance; ultra-endurance activities and such like. We don’t really know what happens there. We know that nitrite levels in the blood tend to fall over time, which opens up the possibility or the interesting question about whether if you supplement nitrate during exercise, whether that may elevate or maintain the elevation of plasma nitrite levels and allow performance to be continued for longer, or for better performance to be enabled later in the competition. So that’s something we’re actually working on right now.
12. What has been the most interesting finding from your research during 2016?
I think one of the most interesting findings we’ve had in recent times is within a study that we did where we looked at simulated soccer performance. We did two 40 minute halves where we replicated the metabolic demands, but simultaneously we asked our subjects to do some quite demanding cognitive function tasks so they were asked to respond as quickly and as accurately to some prompts that they saw on a computer screen in front of them. In the controlled condition as you’d expect, their performance got worse – they were able to think less clearly and they made decisions much more slowly in the second half compared to the first half. That was with the placebo. But when we gave them the nitrate and of course this was a double-blind experiment, to our surprise, their cognitive abilities were better maintained in the second half compared to the first half. So they continued to make similarly accurate, or inaccurate decisions, but they did it with less decline in the rate which they answered. So there seemed to be benefits both on physical performance but also on cognitive performance in that study as well, and of course, when you’re talking about team sports, the ability to make fast and accurate decisions is important as well as the physical component.
13. What can we expect to find from your dietary nitrate research in 2017 and beyond?
So getting my crystal ball out and thinking about where the dietary nitrate story might lead next, I think the direction of travel is definitely in what happens within muscle to enable it to generate more power and for sprint performance to be enhanced – so trying to unveil a mechanistic basis for that is an important next step. We’re also quite interested to know where nitrate is stored. We know that nitrate levels and nitrite levels go up in the blood, but are they stored in tissue – in muscle tissue, for example. And there are animal experiments that indicate that it is – that when you take nitrate, the reservoir of nitrate and nitrite within your muscle is elevated – but that's not yet been shown in humans. So the gradient from muscle to blood and vice versa is going to be an important next step as well.
14. Can you see any medical applications from your research into dietary nitrate?
My research here at the University of Exeter focuses on what happens with nitrate and sports performance and the physiological responses to exercise of different types, but we know that if you can increase nitric oxide bioavailability then you may expect to have some clinical, or health benefits as well. One of the obvious ones is a reduction in resting blood pressure. That’s been very widely researched and we think that can have a positive effect on cardiovascular health across the population – so we should be eating and consuming more nitrate-containing vegetable products, I think. But also lots of people are getting into now, the extent to which nitrate may enhance performance in different types of people within the population. Older folks for example – again if we can reduce the oxygen cost of walking, then that may increase quality of life and improve the amount of physical activity that they do, but also in disease conditions which influence oxygen availability at the muscle – things like heart failure, peripheral arterial disease, then there are potential applications there which other groups, and us to some extent, are investigating presently.
Thank you Andy for sharing your knowledge and experience into dietary nitrate research. I wish you all the best with your research in 2017 and please keep us updated with any advancements that you make.
No problem at all, thanks very much.