We are all aware of how vitamins and minerals can affect our health; rarely a day goes by that there isn’t something in the media about how adequate [insert vitamin or mineral] can decrease [insert disease] risk. But what about their effect on exercise?
In this article we’ll look at how vitamins and minerals affect exercise and how a deficiency might be hampering your performance. We’ll make recommendations on how to best achieve adequate micronutrient levels and highlight certain groups that might be at increased risk of deficiency.
When we exercise we place unique stresses on the body that have the potential to result in increased demand for micronutrients. This rise occurs as the body uses its supply more quickly than at rest to cope with the increased rate of metabolism and therefore energy demand. Vitamins are co-factors in these metabolic processes whilst minerals are often incorporated into enzymes that control the rates of these chemical reactions.
Because of this potential increased demand there are often claims that supplementation with vitamins and minerals can increase performance. This is something we’ll examine in more detail later, but for now we’ll take a look at how deficiency in a number of vitamins and minerals can not only decrease your health but decrease your ability to reach your exercise potential.
Folate And Vitamin B
Severe folate and vitamin B12 deficiency has been shown to increase the risk of anaemia by effecting red blood cell efficiency, which in turn affects your ability to carry oxygen to your muscles and decreases endurance (McMartin, 1997).
As for which foods contain high levels of folate, essentially “green is good”: spinach, broccoli and peas being excellent sources. Often, breakfast cereals are fortified with folate too. Vitamin B12 is found in numerous sources including meat, salmon, eggs and dairy products as well as breakfast cereals being fortified with it (Geissler & Powers, 2011).
Deficiency in vitamin D has been associated with worsening muscular performance, something of keen interest for those of us who lift weights. Cannell et al. (2009) found that compared with deficient individuals, those with adequate levels of vitamin D had increased number and size of type II, fast twitch muscle fibres – which are involved mainly in strength and power production.
Vitamin D, although not a true vitamin (our bodies are capable of synthesising it in our skin via UV light), is an important micronutrient for skeletal development and maintenance, which is of obvious importance to those who exercise as a stronger skeleton helps prevent fractures.
In terms of ensuring adequate status, our indoor/office based society doesn’t really lend itself to vitamin D production via sunlight and as there are very few dietary sources – it is actually believed that a large proportion of the population may be vitamin D deficient. Therefore, if you get very little sunlight, something very likely in a UK winter, it is recommend that you take a vitamin D supplement on a regular basis (NHS, 2012).
That said, excess vitamin D is associated with a build up of calcium in the body, which in turn can damage your kidneys. As supplements often contain at least the RDA of a vitamin, it is important to be careful when taking vitamin D and try not to exceed twenty-five micrograms a day, as recommended by The NHS (2012). This is more than enough to meet the vitamin D Recommended Daily Allowance (RDA) of ten micrograms a day but is still low enough to stop any unwanted side effects (Geissler & Powers, 2011).
- Vitamin D3 Tablets
- Myprotein Vitamin D3
- Vitamin D3
- Vitamin D3 Tablets
- Vitabiotics ultra D3
- Reflex Nutrition vitamin D3
A lot of research regarding the effect of vitamins on exercise looks at the antioxidant properties some of them posses. The idea being that adequate or increased levels of certain antioxidant vitamins might help the body recover from the oxidative damage that exercise induces, and therefore help increase recovery time.
This is a subject that we’ll be looking at in more detail over the coming weeks.
Iron is the part of haemoglobin in red blood cells that attaches to oxygen and allows its transport around the body. Therefore, iron deficiency has the potential to reduce your endurance levels by stopping your muscles from receiving the oxygen they need to produce energy.
Hames (1998) showed that runners have increased risk of iron deficiency compared with the general population – increased red blood cell production is an adaptation of endurance exercise and therefore increases iron demand. In fact, if you undertake any sports/exercise which involves endurance there is a potential for iron deficiency (Lukaski, 2004).
A return to normal iron status from deficiency has been shown to decrease blood lactate (a sign of fatigue) and increase oxygen uptake in exercise tests (Gardner et al. 1977), both of which allow for increased endurance. Meat, nuts, dark green leafy vegetables, beans and brown rice are all good sources of iron (NHS, 2012; Geissler & Powers, 2011).
Clear evidence that magnesium is involved in exercise performance was shown when muscle spasms in a tennis player associated with magnesium deficiency were successfully treated with a magnesium supplement after a few days (Liu et al. 1983). Magnesium plays an important role in ensuring proper cellular function, in particular within muscle cells (Golf, 1993).
Evidence for this was first found by Brilla & Hayley (1992) where they used individuals undertaking magnesium supplementation to show significance increases in strength compared with those not on supplementation during the same training programme. Magnesium is commonly found in green vegetables, nuts, wholegrain bread and meat (NHS, 2012).
Finally, zinc is one of the most important minerals in the body. It is required for more than three hundred enzymes and plays an important role in our immune system and skeletal development (Lukaski, 2004). It is also one of the most prevalent deficiencies amongst exercising adults.
Increased zinc levels, compared with deficiency, have been shown to increase muscle strength and endurance by allowing increased rates of anaerobic energy production in muscle (Powers & Howley, 2008). Good sources of zinc include meat, dairy and bread (NHS, 2012).
There are a number of other minerals that have been shown to affect exercise performance, but those showcased above are the ones that have been proven to have the greatest effect and/or are the most important, in terms of health, not to be deficient in.
Should You Supplement?
We’ve highlighted that deficiency in certain vitamins and minerals can have an effect beyond health, resulting in decreased exercise performance. By ensuring adequate vitamin and mineral levels, you enable yourself to exercise to your potential and help prevent injuries.
In most cases it is recommended that you attempt to achieve this status via dietary sources alone, without relying on supplements (apart from in the case of vitamin D, as mentioned above). Clearly your mum had it right all along and eating your vegetables really does make you big and strong.
A varied diet including lean meat, plenty of fruits and vegetables as well as whole grains allows you to be safe in the knowledge your workout isn’t being affected by low micronutrient levels.
However, there are situations where diet alone might not allow you to get enough vitamins and minerals. One such situation is when combining dietary changes with exercise for fat/weight loss. Often during this time people leave food groups out of their diet in order to cut calories and help acheive their goals, especially when looking for rapid results.
This can stop these individuals from receiving the micronutrient provision they need in order to exercise at maximum capacity, and may even hinder their weight loss as a result. If you are undertaking a period of rapid fat loss whilst continuing to exercise you may benefit from supplementing your diet with a multivitamin regularly.
Another group of people at risk of deficiency, particularly in minerals like iron and zinc, are vegetarians (Geissler & Powers, 2011). After all, some of the best, and most bio-available (ease with which our body can use the micronutrient version) sources of metallic minerals are meats. Therefore if you are a vegetarian who exercises regularly (particularly endurance exercise) you should benefit from supplementing your diet with a multivitamin.
Despite the specific nature of deficiencies in vegetarians, you are better off taking multivitamins rather than an individual mineral supplement (unless indicated by your doctor). The reason for this is that individual supplements often contain higher levels of the mineral in question than multivitamins and therefore it’s easier to consume excess.
Here are some of the most popular multivitamin and mineral tablets, should you require them:
- Complete Multivitamin Complex™
- Myprotein Alpha Men
- Elite Man
- Vitabiotics Wellman Tablets
- Centrum Advance
- Radiance Multi Vitamins & Minerals One A Day
- Usn multiplex Sport
- Optimum Nutrition opti Men
- Universal animal Pak
Both vitamins and minerals can have an effect on exercise performance. Deficiency limits the rates at which metabolic processes occur within the body and decreases performance. Adequate status therefore ensures your body is capable of working to its potential.
In order to achieve adequate status it is recommended you attempt to do this via dietary sources, using a varied diet containing lean meat, fruit, vegetables, whole grains and dairy in moderation.
Certain groups – such as those undertaking rapid weight loss and vegetarians – can be at increased risk of vitamin and mineral deficiency and might benefit from the use of supplements. When supplementing, you should always ensure that you don’t exceed the RDA, especially when using individual supplements instead of multivitamins.
To find up to date RDA’s, the NHS website is an excellent resource (www.nhs.uk). Finally, most of us could probably benefit from increased vitamin D levels – as this is exceedingly difficult in the UK, a supplement is advisable (NHS, 2012).