As a personal trainer or fitness professional, your role extends beyond just guiding clients through workouts and exercise routines. You’re often the first point of contact for health and fitness advice. 

Clients often use their PTs as a sounding board for all sorts of questions including on topics such as nutrition and health supplements to help them along on their fitness journey. This means it’s important for you to have a comprehensive and up-to-scratch understanding of these topics to the best of your ability. 

With this in mind it’s also important to recognise the scope and limitations of nutritional advice that personal trainers can provide. Whilst you can offer general guidance on healthy eating habits and supplementation, specific medical or nutritional advice should be left to registered nutritionists, dietitians or medical professionals.

This guide aims to take you through the world of health supplements, providing you with the knowledge to offer informed, responsible advice to your clients to go alongside any formal qualifications you get from personal training courses and nutrition courses.

Understanding health supplements

Health supplements are products designed to add nutritional value to a person’s diet. They come in various forms, including tablets, capsules, powders, liquids and even gummies. These products usually contain vitamins, minerals, herbs, amino acids, enzymes and other dietary substances.

In the United Kingdom, supplements are regulated as foods by the Food Standards Agency (FSA) and must comply with food safety regulations. Unlike medicines, dietary supplements don’t require pre-market approval. However, manufacturers are responsible for ensuring their products are safe and properly labelled. This regulatory framework means that whilst supplements are generally considered safe, the level of scrutiny they undergo is different from pharmaceutical products.

It’s crucial to differentiate between dietary supplements, which are intended to support overall health, in comparison to performance enhancers, which are specifically designed to improve athletic performance. As a personal trainer, your focus should primarily be on dietary supplements that support general health and wellbeing.

Understanding the purpose of supplements is key. They are designed to supplement the diet, not replace whole foods or a balanced eating plan. Supplements can be beneficial in addressing specific nutritional deficiencies or supporting particular health goals. However, they should never be viewed as a magic solution or a substitute for a healthy lifestyle.

When discussing supplements with clients, it’s important to emphasise that although they can be beneficial, they are not essential for everyone. A well-balanced diet can often provide all the necessary nutrients. The decision to use supplements should be based on individual needs, health status, and in many cases, professional medical advice.

Key categories of science-backed health supplements

Let’s explore some of the most common categories of health supplements.

Vitamins and minerals

Vitamins and minerals are known as micronutrients. These are essential to the body in small amounts, as opposed to macronutrients (carbohydrates, proteins, and fats) which are required in comparatively larger amounts.

Vitamins are organic compounds necessary for various metabolic processes, whereas minerals are inorganic elements required for structural and functional roles in the body.

Multivitamins

Multivitamins are an effective way to ensure you’re getting your recommended quota of vitamins and minerals. They’re designed to fill nutritional gaps in the diet, especially for those with restricted eating patterns or increased nutritional needs. Whilst a balanced diet should provide most necessary nutrients, multivitamins can serve as a nutritional safety net.

A quality multivitamin will support overall health and wellbeing, potentially improving energy levels and immune function. Some studies suggest they may lower the risk of certain chronic diseases.

Vitamin B12

A large and complex vitamin, B12 is stored in the muscles and the live. It delivers a range of benefits, such as boosting bone density and reducing fatigue. Primarily found in meat products, B12 can be a challenge for those on a meat-free diet. However, non-animal foods such as spinach, mushrooms, potatoes and beetroot contain vitamin B12.

If your diet is low in B12, it’s a good idea to look for supplements. For a personal trainer yourself, this is one of the most valuable vitamins to be aware of. That’s especially the case if you’re a successful personal trainer with a long list of clients, meaning your days are spent on multiple one-on-one sessions. B12 will help keep you alert and ready to tackle the next client on your daily schedule.

Vitamin D

It is estimated that around 1 billion people worldwide suffer from vitamin D deficiency. Often called the ‘sunshine vitamin’, Vitamin D is crucial for numerous bodily functions. It’s primarily synthesised in the skin when exposed to sunlight, but many people, especially in the UK where sunlight can be limited, may benefit from supplementation.

Vitamin D is essential for calcium absorption and bone health, supports immune function, and may play a role in mood regulation and mental health. Whilst it’s fairly common knowledge vitamin D can combat depression, it’s also useful for:

• Improving weight loss
• Fighting inflammation
• Lowering high blood pressure
• Improving muscle strength.

The NHS recommends that adults and children over the age of one should consider taking a daily supplement containing 10 micrograms of vitamin D, especially during autumn and winter.

Zinc and magnesium

These minerals play vital roles in numerous bodily functions and are particularly important for physically active individuals. They often come together in a supplement, such as ZMA.

Magnesium is a chemical element that’s highly beneficial for the body, key in energy production and muscle and nerve function. Magnesium is a potent antioxidant that can boost exercise performance. It may also help improve sleep quality and reduce stress and anxiety. You will find magnesium in:

• Pumpkin seeds
• Almonds
• Spinach
• Cashews
• Peanuts
• Dark chocolate
• Coffee.

Zinc supports immune function, aids in protein synthesis, and is important for taste and smell.

Both zinc and magnesium are lost through sweat, making them important considerations for athletes and those engaged in regular intense exercise.

Protein

Proteins are one of the essential macronutrients our body needs. The body breaks down protein from food or nutritional supplements into the amino acids it uses. They are crucial for growth, repair, and maintenance of our bodies, especially in our muscles and bones. They also support the functioning and healthy development of organs such as our brain and heart, as well as our immune system.

If there’s one nutritional supplement it’s important to learn more about, protein is the one. Protein has been proven to boost athletic performance, help with building muscle and can encourage weight loss. Protein powders are among the most popular supplements, available in various forms to suit different dietary needs and preferences.

The British Nutrition Foundation recommends adults consume 0.75g of protein per kilogram of bodyweight per day. So, if you weigh 60kg, it’s recommended that you eat 45g of protein a day.

For those focusing on resistance training and building muscle, higher protein requirements are likely necessary. Many studies have shown protein intakes of 1-1.6g/kg bodyweight to be more beneficial.

There are many forms of protein supplements including:

• Whey Protein – Derived from milk, whey is a fast-absorbing protein rich in essential amino acids. It supports muscle protein synthesis and contains all essential amino acids.
• Casein Protein – Also derived from milk, casein is a slower-digesting protein. It provides a steady release of amino acids.
• Plant-based proteins – Options like pea, rice, hemp, or soy protein cater to those following vegetarian or vegan diets. Plant-based protein supplements are often enriched with vitamins and minerals and can be combined to provide a complete amino acid profile.

Many foods are high in protein, so if your diet matches your health goals, you likely won’t need protein supplements. Just makes sure that you’re eating plenty of:

• Lean beef
• Chicken
• Seafood
• Fish
• Eggs, milk, cheese and yoghurt
• Peanut butter
• Pasta
• Lentils and beans
• Nuts and seeds

However, vegetarians and vegans may need extra protein in their diets as they won’t be getting any from meat or fish.

Amino acids

One of the most popular amino acids to take for those involved in health and fitness is creatine. Creatine is a naturally occurring compound, produced by the body in small amounts and found in meat and fish.

The major benefit of supplementing with creatine is that it increases phosphocreatine stores in muscles, which is crucial for rapidly regenerating ATP. This is important when taking part in high-intensity exercise and explosive movements. In turn creatine supports muscle growth and strength gains. 

Creatine is a safe supplement with over 700 human studies supporting its efficacy. Creatine monohydrate is the most studied and generally recommended form. Around 5g of creatine a day can be effective.

Omega-3 fatty acids

Your body can’t produce omega-3s (specifically EPA and DHA), so you need to get it from food or supplements. Omega 3s are essential fatty acids that are key in supporting heart health, reducing inflammation and are important for brain function and development. Omega 3s can also help prevent blood clots and improve oxygen production. It protects the cardiovascular system and helps to soothe swollen joints

As a fatty acid, the best source of omega 3 is in oily fish, such as salmon, mackerel and trout. If you don’t eat much oily fish though, supplementing with Omega 3s is a great choice. A large meta-analysis of 149,000 participants published in 2021 found that omega-3 fatty acids reduced cardiovascular mortality and improved cardiovascular outcomes.

For vegetarians or vegans, omega supplements derived from algae are available. It can also be found in some oils, such as linseed oil and flaxseed oil, as well as in some green and leafy vegetables and seeds and nuts.

Structural proteins

Collagen is one of the most important structural proteins in the body. Although it’s one of the most abundant proteins, collagen supplementation is gaining popularity. 

The benefits of collagen are clear – support of joint health, connective tissue strength and improved skin condition. 

While the body produces collagen naturally, production decreases with age, leading some to turn to supplementation.

Probiotics health supplements

Probiotics are beneficial bacteria that support gut health – something which is increasingly being recognised as crucial for overall wellbeing. Your body already has a whole collection of gut friendly microbes, but probiotic gut health supplements can add to this existing supply. You can also find probiotics added to yoghurts too. 

The benefits of probiotics are clear – better digestive health, immune functioning and potentially even benefits for mental health. 

Potential risks and side effects of health supplements

Whilst generally safe when used as directed, supplements can have side effects or interact with medications. Even natural supplements can have side effects as our bodies can react differently.

Researching potential side effects before taking a supplement is vital and shouldn’t be overlooked, particularly if that supplement is new for someone.

Adhering to recommended dosages is crucial. Even essential nutrients can be harmful in excessive amounts.

How to evaluate supplement quality

When it comes to supplements, prioritise high-quality choices. Advise clients to read labels carefully and look for clear, comprehensible ingredients.

Be wary of proprietary blends that don’t disclose individual ingredient amounts. These can mask low doses of effective ingredients. Supplements should be dosed effectively and align with recommended daily values or research-backed effective doses.

Caution clients against products promising miraculous or instant results. These exaggerated claims are often false. Encourage them to look for independent reviews and reputable companies.

Other important factors to check include allergens and expiration dates. Certifications like Informed Sport ensure products are tested for banned substances, whilst NSF International verifies that product contents match the label.

Integrating supplements into a balanced lifestyle

Emphasising that supplements should complement, not replace, a balanced diet and healthy lifestyle is vital. 

Here are some key points on guiding clients in integrating supplements effectively:

1. Importance of whole foods – Stress that supplements are not a substitute for a varied, nutrient-rich diet. Educate clients on the benefits of whole foods which contain high levels of macro and micronutrients. Encourage clients to focus on improving their diet before turning to supplements.
2. Supplements as complementary – Explain how supplements can fill specific nutritional gaps or support particular health goals. Provide examples of when supplements might be beneficial, such as vitamin D in winter months or protein powder for recovery after intense workouts.
3. Personalised approach – Highlight that nutritional needs vary based on factors like age, gender, activity level, and health status. What works for one person may not necessarily work for another. For personalised advice, recommend consulting with a healthcare professional or registered nutritionist. Read more on how to become a nutritionist.
4. Lifestyle factors – Reinforce the importance of other lifestyle factors, such as adequate sleep (7-9 hours for most adults), stress management techniques, regular physical activity, and hydration.
5. Monitoring and adjusting – Advise clients to pay attention to how they feel when taking supplements. Encourage regular check-ins with healthcare providers to assess the need for continued supplementation.

By promoting a holistic approach to health and fitness, rather than reliance on external factors, you can help clients understand the proper role of health supplements in their overall wellbeing.

Advising clients on health supplements

As a personal trainer, it’s crucial to establish clear boundaries when advising on areas such as nutrition and supplementation. Your role is to provide general information and guidance, not to prescribe specific supplement regimens. This is why personal trainer insurance is important.

Here are some guidelines for advising clients:

• Establishing boundaries – Clearly communicate the limits of your expertise. Explain that you can provide general information about widely recognised supplements, but you’re not qualified to prescribe specific regimens. Stick to discussing supplements that are well-researched and generally considered safe.
• When to refer – If your client has a specific health concern or medical condition, always refer them to a registered nutritionist, dietician, or their GP. If you’re interested, check out our post on nutritionist salaries UK.
• Staying updated – Commit to ongoing education about nutrition and supplementation. The field is constantly evolving, so it’s important to base your advice on the most current, evidence-based information. Follow reputable nutrition and sports science journals or organisations for the latest research.
• Providing balanced information – When discussing supplements, present both potential benefits and risks. Encourage clients to be critical consumers and to research supplements thoroughly.
• Documenting advice – Keep records of any supplement-related discussions with clients and document any referrals made to healthcare professionals. Although the vast majority of cases will be absolutely fine, it’s always worth keeping records.

Remember, your primary role is to support clients in making informed decisions about their health and fitness, not to act as a medical or nutritional expert. By maintaining these professional boundaries, you protect both your clients and yourself whilst providing a valuable service within your area of expertise.

Wrap up on health supplements for personal trainers

As a personal trainer, a solid understanding of health supplements allows you to provide valuable guidance to your clients within the appropriate scope of practice. Remember that supplements are just one piece of the health puzzle – they work best as part of a holistic approach to wellness that includes proper nutrition, regular exercise, adequate sleep, and stress management.

Stay curious and continue educating yourself about nutrition and supplementation. The field is constantly advancing, and staying informed will help you provide the best possible service to your clients. By understanding both the benefits and limitations of supplements, you can guide your clients towards making informed decisions about their health and fitness journey.

Ultimately, your role is to empower clients with knowledge, encourage them to seek appropriate professional advice when needed, and support them in achieving their health and fitness goals through safe, ethical, and evidence-based practices.

You can also read more about our nutrition courses here. Our courses offer flexible learning that can be completed in just 12 weeks.