A specific supplement blend has been shown to boost athletic performance. Could it work for you, too?
We'll hazard a guess that you, Women's Health Collective member, are in the business of optimisation.
If you don't don a pair of rubber gloves and clean the shower while you're still in it, then we suspect you save your phone calls for walks and use queues to catch up on your reading.
So here’s something that’ll horrify you. If you’ve been optimising your cardio performance via hamstring activation and (urgh) hill sprints, there could be a more efficient way to get there - one that involves no physical exertion whatsoever.
An elixir that, in just one month, could shave almost a minute off your three-mile run. Interested? So were we.
Researchers at Ohio State University have found a way to shave an average of 54 seconds off the three-mile time of female participants.
The same method helped them to cycle further in 25 minutes directly afterwards and boosted their performance in a 90-second step test. What's more, they weren’t even regular cyclists.
The game-changing addition was a teaspoon-sized blend of five common or garden nutrients.
The winning combo? The minerals iron, copper and zinc, plus carnitine, derived from amino acids, and phosphatidylserine, a blend of fatty acids and amino acids.
They’re all nutrients that you’re probably getting already, just in insufficient quantities; nutrients that had such a powerful effect because many fit, young women are deficient in them.
How can nutrients boost performance?
The nutrients used in the Ohio State study are micronutrients. Unlike macronutrients – carbohydrate, fat, protein – you don’t tend to hear them spoken about across office desks or gym changing rooms.
‘But these vitamins and minerals play incredibly important roles when it comes to keeping you healthy, affecting everything from fluid balance to cell metabolism,’ says sports dietitian Aisling Pigott.
‘We have to ingest all of these micronutrients through diet and, for most people, because you only need tiny amounts of them, if you eat a varied diet, you can get what you need through the food you eat.’
But not always. And micronutrient deficiencies - or ‘micro-deficiencies’ - are surprisingly widespread.
Two thirds of UK women aren’t reaching their recommended intake for iron, which helps red blood cells carry oxygen around the body.
Meanwhile one in five aren’t reaching the RNI for zinc – a mineral responsible for helping your immune system fight off bacteria.
These under-the-radar dietary deficits are having a negative effect on women’s fitness performance.
‘We know that young women often have micro-deficiencies and often happen in the very nutrients that play a role in how cells work during exercise,’ says Robert DiSilvestro, professor of human nutrition at Ohio State, and author of the study.
One reason? Your old friend, menstruation. ‘Women who bleed an average amount during their period [five days of manageable flow] lose around 1mg of iron per cycle,’ says Renee McGregor, a sports dietitian who specialises in eating disorders and WHC Expert Panellist.
For those with a heavy cycle, medically known as menorrhagia, the iron loss can be five to six times as great.
‘In general, women don’t appreciate the changes that occur within the body through their whole menstrual cycle and how important it can be – especially if you’re exercising regularly – to tailor their nutritional needs to their cycle,’ adds McGregor.
Can exercise create a deficiency?
While it’s not known whether the women participating in the Ohio study were deficient prior to taking the supplement, it’s likely.
‘We wanted the study to focus on women who were already recreationally fit,’ says Professor DiSilvestro. ‘People who could already run three miles without it being a terrible burden.’
For these women, aged 18 to 30 (although the study can’t verify it, it’s likely the findings apply to women beyond that age bracket, too), who exercised aerobically for between two and three hours a week, there’s an increased risk of micro-deficiencies.
‘Exercisers, especially runners, can lose iron via a number of routes,’ explains Dr Bartosz Buczkowski, senior lecturer in nutrition at Manchester Metropolitan University.
‘Every foot strike creates pressure that potentially destroys a small amount of red blood cells,’ he explains.
Iron can also be lost, he adds, through sweat and through the gastrointestinal tract during endurance exercise – the latter due to microscopic tears in the gut wall as circulation to that area dials down during exercise.
Unsurprisingly, a lack of iron decreases your red blood cells’ capacity to transport oxygen to exercising muscles.
Your VO² max (maximal oxygen uptake by muscles, heart and lungs and an athlete’s go-to aerobic endurance measurement) is also determined primarily by the oxygen-carrying capacity of your blood, which, you guessed it, requires iron.
What are the best dietary sources of iron?
So, it goes without saying that you require an adequate supply. The NHS recommends 14.8mg per day for women aged between 19 and 50, and 8.7mg if you’re over 50.
This equates to roughly a 400g portion of steak and means that if, like 14% of the UK population, you’re cutting back on meat, you’re more likely to miss out.
‘Vegans have a hard time with iron,’ says Professor DiSilvestro. Some of the most iron-rich foodstuffs available, such as spinach and fortified cereals, have the worst absorption rates.
That means that while their numbers look good, a limited amount of their iron content actually reaches the bloodstream.
And what about supplements? ‘No iron supplements can compete with the haem iron in meat,’ he explains.
Confused? Dietary iron comes in both haem and non-haem forms. Your body absorbs haem iron – found only in animal meat – much better, but over half of the iron found even in meat is non-haem, so the nutrition label won’t reflect the amount of iron your body’s primed to take on.
‘Meat is such a first-rate source of iron because it contains both kinds,’ adds Professor DiSilvestro. ‘That’s why we used quantities of iron in our studies that were above the RNI doses.’
The theory being that you’d have to OD on non-haem iron to get the same bang for your buck. So, what’s a woman who trains and prefers to be powered by plants to do?
‘You can boost absorption of non-haem iron to some extent by eating good amounts of vitamin C.’
If you’re supplementing, McGregor recommends Proto-col to her clients, as its products are batch-tested and certified by supplement testers Informed Sport.
Can any other deficiencies affect your fitness?
But while iron tends to grab the micro-deficiency spotlight, it’s only part of the story. ‘With the rise of plant-based diets, we’re also starting to see individuals with iodine and B12 deficiencies,’ says McGregor.
And, she adds, most Brits will have a vitamin D deficiency – especially during the winter months, and the standard recommended dose of vitamin D isn’t sufficient for those who are very physically active.
If you’re a heavy-duty exerciser (we’re looking at you, WHC member) McGregor recommends taking a supplement between September and April.
Copper, found in high amounts in liver and oysters, but also – to a lesser degree – in almonds and sesame seeds, should also be on your radar; there’s some research to support that ingesting above-RNI levels of copper can improve cycling times.
And, in a flicker of good news for vegans, Professor DiSilvestro explains that the copper you get from a vegan diet can exceed the amount you get from diets that contain meat.
Remember the third band member – zinc – in Professor DiSilvestro’s study? One in five of us aren’t getting enough.
That's important – as studies show that suboptimal zinc levels can lead to increased DOMS. Other research suggests that supplementing zinc can boost your VO² max, too.
As for the other ingredients in Professor DiSilvestro’s recipe, there’s plenty left to learn. But a good approach is to re-think the way you fuel your workouts more generally.
‘Any restrictions placed on diet will lead to nutrient deficiencies,’ says McGregor, including for those whose training plans factor in nutrition, too.
‘A great source of a number of micronutrients – including iron, B vitamins, magnesium and vitamin E – is whole grains, but some people remove carbs from their diets without appreciating that,’ says McGregor.
The real hack? ‘Some micronutrient deficiencies, like iron or vitamin D, may be diagnosed by a blood test,’ says Pigott. ‘But the best way to prevent deficiency is to have a varied, balanced diet.’ We've said it before and we'll say it again: you can't out-train a bad diet.
Micro-deficiencies at a glance
Suspect you’re low in any of the below? Find out what you can do about it
Iron
- It increases the amount of oxygen available to your muscles, keeping them working for longer and boosting your VO₂ max.
- Meat is the best source, but you can get a fix from spinach and fortified cereals.
- Non-meat iron is less bioavailable, so up your vitamin C intake to boost absorption.
Copper
- Copper’s involved in the final step of producing energy in your muscles.
- It also helps the body detoxify free radicals, which can contribute to painful DOMS.
- Food sources include liver and oysters, but a vegan diet rich in almonds and sesame seeds can actually be higher in copper than a meat eater’s.
Zinc
- If your body is low on zinc, you’re susceptible to devastating DOMS, as zinc is crucial for muscle recovery.
- Zinc also supports your immune system and ups your VO₂ max.
- Shellfish, lean meats and eggs contain high levels of zinc.
- Vegan? Top up with spinach, legumes, nuts and seeds.
Phosphatidylserine
- Adequate levels could lessen post-workout fatigue, improve reaction times and keep exhaustion at bay for longer when running or cycling.
- The best dietary sources are oily fish, offal and soya.
- Smaller amounts can be found in white beans if meat is off the menu.
Carnitine
- Carnitine is used to transport fatty acids to your cells’ mitochondria, which in turn provide the energy you need to fuel your workouts.
- Red meat contains the highest levels of carnitine.
- It can also be found – in smaller amounts – in dairy, cod and even asparagus.
