Supplements are on area of nutrition that is often discussed in depth, especially for those that are physically active. As the name suggests, nutritional supplements are any product that aims to ‘supplement’ the diet with nutrients that could potentially be missing. It only takes one walk around your local supermarket, pharmacy or health food shop to see a huge selection of vitamins, minerals and various other supplements in incomprehensible ranges, doses and combinations. For the general population it can be confusing to know if taking a supplement is necessary, and considering cost, safety, quantities and qualities are all variables that can add to confusion. For athletes on the other hand, supplements can be useful to build muscle, increase endurance, assist with weight loss or gain, rehydrating, overcoming deficiencies or aid recovery. Sports supplements are a category of nutritional supplements whose purpose is to supplement the normal diet to improve general health and well-being or enhance performance. They may include powders, capsules, tablets, drinks or bars, some you may have seen include protein, creatine, caffeine, BCAAs and pre-workout, which go beyond the usual vitamins and minerals (micronutrients) often suggested for general health.
So what’s the hype with supplements for athletes vs the recreational exerciser, are there any you should be taking? Let’s take a deeper look.
Let’s start with the small stuff
The humble multivitamin is often thought of as the answer to everyone’s health concerns. Claims such as boosting immunity, curing disease and fighting infection are all things that have been asserted over the years. It’s thought to cover all basis and be a safety net to health. However most people get everything they need by eating a well-balanced, varied diet.
For athletes, taking a multivitamin can provide reassurance that they are doing everything possible to reduce illness, avoid fatigue and enhance recovery as much as possible. Perhaps almost producing a placebo effect in some ways. Athletes usually have such high energy requirements and are focused on eating a good diet that they are meeting vitamin and mineral requirements anyway. It’s also important to remember consuming micronutrients from food provides the body with other beneficial elements such as fibre, which cannot be obtained from a supplement. Additional absorption rates from supplements vary. For example, water soluble vitamins will simply be excreted from the body where consumed in excess.
Iron is a mineral which is not often thought of as essential to supplement but is one that many are deficient in with about being aware. Iron has an essential role in aerobic energy production in the body. It is important for making haemoglobin, a protein contained in red blood cells which transport oxygen from the lungs to the muscles and other tissues. As a result our tissues and muscles can produce energy aerobically (with oxygen).
Some individuals are more at risk of iron deficiency than others. For example individuals following an energy restricted diet, females with a menstrual cycle and vegetarian or vegans. Athletes and individuals that are recreationally active may also have higher iron requirements than others due to training adaptations, making them more susceptible to deficiency. Training or exercising regularly can increase the total number of red blood cells and total blood volume in the body. Which allows more oxygen to be delivered to muscles. The more red blood cells we have, the more iron that is needed to support their function. Athletes can also experience a higher loss of iron through sweat.
Runners and those involved in high impacts sports, which involve the body beating against a surface can lose more iron through damage to red blood cells on impact. Endurance athletes may be at an increased risk due to loosing iron from bleeding in the gut which happens as the gut stops functioning as effectively during long duration exercise.
Research surrounding iron supplementation is mixed. Evidence does suggest correcting iron deficiency can improve work capacity, but evidence is conflicted relating to milder iron deficiency without anaemia and its consequences on performance. Taking an iron supplement above 45mg per day can lead to adverse effects such as gastric upset, nausea, constipation, vomiting and fainting. At recommended intakes of 8mg per day for men and 18mg per day for premenopausal women, no adverse effects have been observed.
Vitamin D plays an important role in stimulating calcium and phosphorus absorption, which is essential for bone, teeth and muscle health. Ongoing research also suggests vitamin D is important for regulating blood pressure, insulin production, cell growth, genetic coding and immune function. In the winter months, October to April, a 10 microgram Vitamin D supplement (per day) is advised for the general population aged 4 years and over.
This is to prevent deficiency of vitamin D as we synthesise this vitamin from the sun. Athletes are certainly part of this group and would benefit from supplementing with vitamin D.
Protein and building muscle is a big part of today’s fitness industry. It’s pretty well known than protein is needed to build muscle mass and help recovery, but protein is also a great source of many vitamins and minerals, is involved in a range of metabolic interactions in the body and makes up part of the structure of every cell and tissue in the body.
Taking a protein supplement in the form of shakes and powders is often associated with recovering after a workout and in particular for strength and resistance training. Research supports this suggesting meeting recommended protein intakes can optimise muscle training response during exercise and the recovery period. BUT it doesn’t have to always be shakes and powders. Intake of protein from foods including meat, chicken, fish , eggs, tofu, beans and legumes, has the same impact on the body as protein shakes. Protein shakes can be great if you struggle to hit your required target each day or need a convenient and quick fix, but ultimately sourcing protein from whole foods should be first priority.
For sedentary people and recreational exercisers, the daily protein requirement is 0.75g/kg body weight (BW). For higher training intensities and athletes the recommended intake is in the range of 1.2-2.0 g/kg BW. That’s equivalent to 96-160g per day for an 80kg athlete.
Protein is not only important after training. A number of studies suggest that consuming protein plus carbohydrate before and during prolonged, high intensity exercise stimulates muscle protein synthesis during exercise, minimises protein breakdown, improves recovery and results in less muscle damage.
Caffeine is a pretty well-known stimulant. It blocks the activity of the neuromodulator adenosine, an organic compound found in our DNA and RNA. This reduces perceived pain and exertion. Results of the effectiveness of caffeine are mixed, but research suggests consumption before exercise may enhance performance in endurance-type activities such as running as well as intermittent, long-duration activities such as football.
Caffeine can have adverse effects including insomnia, restlessness, nausea, vomiting and arrhythmia. The recommended daily limit is 400 milligrams, this is around 4 cups of brewed coffee.
Creatine is an amino acid which helps to supply muscles with energy for short term, predominantly anaerobic activity. Outcomes of supplementing with this amino acid suggest it may increase strength power and work from maximal effort muscle contractions. Over time it may help the body adapt to athlete-training regimes but can have little impact for endurance sports. There is also research indicating creatine may help reduce injury risk and enhance recovery.
An important note around caffeine and creatine: Caffeine appears to blunt the effect of creatine if they are taken together. Avoiding caffeine intake in the first 5-7 days of taking creatine can help to avoid this, and then to take the two as far apart as possible
BCAAs are branched chain amino acids which make up one third of muscle proteins. The theory behind this supplement is that it can help prevent the breakdown of muscle tissue during intense exercise. They are not essential for sufficient muscle protein synthesis to occur and taking them alone has shown no benefits in supporting muscle mass gain.
As with protein, consuming BCAAs in your diet, which involves eating complete proteins should be first priority. A complete protein refers to that containing all of the essential amino acids, those we can’t synthesise ourselves in our body, we must consume them. If sufficient calories, protein and carbohydrate are being consumed there appears to be little benefit of taking BCAAs.
This is only scratching the surface when it comes to supplements for athletes, there are many more from antioxidants to betaine and glutamine, the list goes on. If you chose to take any supplements, always buy from a reputable source, for example your local supermarket or chemist/pharmacy, check the label and make sure you really need them. Ask your doctor, dietitian, pharmacist or chemist if you are concerned.