Does this claim make sense? Is it supported by scientific evidence? Is it safe? Is it legal? Supplements can introduce an overwhelming amount of confusion to newcomers and elite athletes alike. In a world of in-your-face marketing and cheap ingredients it’s unlikely that the noise produced by supplement-focused businesses is going to quieten any time soon.

This post is going to help explain the research behind the claims of some of the “nosiest” supplements in an attempt to help you take the most informed and sensible decisions in relation to your fitness goals.

Classifying Supplements

The Australian Institute of Sport (AIS) is a world leader in the classification of sports supplements. There are 4 categories in which certain supplements are placed:

A – Approved Supplements (supported for use in specific situations)

B – Supplements “under consideration” (deserving of further research and considered for provision to athletes)

C – Supplements that have no clear proof of beneficial effects

D – Banned Supplements

Australian Institute of Sport Logo

Group A Performance Supplements

Most people are interested in the supplements that are actually going to have a positive influence on their sporting performance. Why spend £10 on a supplement that doesn’t have any sound evidence behind it when you can spend £10 on a supplement that does? We’ve made a list of all the supplements that can be found in Group A (those supported by scientific evidence).

It is important to remember that specialist advice should be sought before introducing a new supplement into your diet; additional investigation may be required to identify specific levels for individuals, especially if they have pre-existing medical conditions or are taking medication.


Caffeine represented by Coffee
What is it?
Mildly addictive stimulant found naturally in cocoa, tea and coffee.
Added to energy drinks, soft drinks and some medication.

Boosts energy levels
Alleviates fatigue
Increases concentration and focus

Who Can Benefit?
Those that engage in a range of sports:
Endurance (over 60 mins in duration)
High intensity (1-60 mins)
Team and intermittent effort sports

Safe Levels
Up to 400mg/day is considered a safe limit for adults
Pregnant women should consume no more than 200mg/day
Children and adolescents should consume no more than 100mg/day
A cup of home brewed coffee generally contains about 100mg. A “venti” cup of Starbucks coffee can contain over 400mg!

Side Effects
The below side effects can occur when ingesting too much (in general over 500mg/day)
Stomach upset
Fast heartbeat
Muscle tremors

Beetroot Juice

What is it?
Well….the juice of a beetroot. It tastes pretty vile.

It contains high amounts of nitrates. Nitrate is a precursor for Nitric Oxide which can:
Increase blood vessel dilation
Increase oxygen delivery
Increase nutrient delivery to muscles
Delay fatigue

Who Can Benefit?
Those engaging in endurance events like running and cycling.

Safe Levels
A typical dose is the equivalent to 300mg of nitrate which can be found in:
500ml of juice
140ml of concentrated juice “shot”
200g of cooked beetroots

This can be taken daily for a week or 1-2.5hrs prior to an event. We strongly recommend practising a strategy in training first!

Side Effects
No serious detrimental side effects but it has been reported to cause GI distress in some people and will also give your urine and stools a (sometimes significant) pink “tinge”!


Beetroot and Vegetables


Bicarbonate Supplement
What is it?
A naturally occurring, alkaline salt.

Regulates pH of body
Buffers lactic acid produced during anaerobic metabolism

Who Can Benefit?
Those that engage in high intensity exercise involving predominantly anaerobic metabolism.

Safe Levels
0.3g per kilogram of body weight, 1-2 hours prior to exercise. It should always be consumed with plenty of water.

Side Effects
May cause gastrointestinal distress.

Omega 3 Fatty Acids

What are they?
Polyunsaturated fats commonly found in fish oils – yuck! They come in 2 forms: EPA and DHA. Your body can’t make Omega 3 Fatty Acids on its own.

You may be taking them already for your heart as they have been shown to reduce triglyceride levels and keep your arteries clear. In sporting terms they are reported to:
Reduce muscle soreness
Improve oxygen & nutrient delivery
Reduce inflammation
Increase muscle synthesis

Who can Benefit?
Because of the factors mentioned previously, they can benefit a wide range of athletes. Sports performance has been shown to improve in endurance athletes taking Omega 3 supplements.

Safe Levels
500 to 1,000 mg per day—you would need to eat at least two servings of like salmon, tuna, or mackerel each week to get to these levels. So if you’re not a fan of fatty fish then a supplement can be a good option.

Side Effects
Some people can get a slight stomach upset; this can generally be avoided if the supplement is consumed with food. The quality of supplements can vary hugely between manufacturers so it’s usually worth investing in a trusted brand that manufactures following strict standards. The most common and least sociable side effect is probably “fish breath”!

Omega 3 Fatty Acids

Beta Alanine

What is it?
A naturally occurring amino acid (the building blocks of protein and muscle tissue).
Used to make carnosine, a muscle “buffer” that neutralises muscle acidity.

Increase in work capacity
Decrease in fatigue
Strength gains
Improved performance
Improved tactical performance

Who Can Benefit?
Suited to several sports:
Weight lifters
Team sports

Safe Levels
4-6g daily for 6-10 weeks

Side Effects
There is currently no evidence of detrimental side effects. The only reported side effect is paraesthesia (tingling/pins & needles).


What is it?
An organic acid that occurs naturally and helps to recycle the energy of muscle cells

It can fuel the body during high intensity activity which can result in:
Improved performance
Increased lean body mass
Reduced fatigue

Who Can Benefit?
It’s very well suited to high intensity sports like:
Weight Lifting
Team Sports

Safe Levels
Most creatine is taken in the form of creatine monohydrate and there are many different recommendations for dosage. A typical “maintenance” dosage would be:
1 x 5g dose per day for 12 weeks followed by a 4 week break (generally it is taken post workout)

Side Effects
There is currently no evidence of detrimental side effects. However, some individuals experience mild side-effects like weight gain (due to intra muscular water retention). The form of supplement is also important so it’s necessary to research your chosen source!