8 ways your diet and workouts could be hurting your skin

You hit the gym, eat a healthy diet, drink your water, yet still struggle with bad skin? It’s not just you. Active people often assume their skin should be glowing, but dry skin, breakouts, and signs of ageing are common. 

Why? Because your skin doesn’t just reflect your skincare – it reflects your lifestyle. And if you’re training hard, under-fuelling, over-supplementing, or just not recovering well, your skin may start to show the strain. 

Learn why being healthy on the outside doesn’t always mean your skin is thriving on the inside. 

1. Training stress and skin flare-ups
2. Cutting calories? Your skin’s not a fan
3. Supplements and skin side effects
4. Sweat, gear, and hygiene habits
5. Macros? Nailed. Micros? Maybe not.
6. Gut stress = skin stress
7. Happy liver, happy skin
8. Hydration is key

• Bonus tip
• Your skin shouldn't suffer for your fitness

1. Training stress and skin flare-ups
 

Intense workouts raise cortisol, your body’s main stress hormone. You might be gaining muscle, but if cortisol’s high, your skin could be losing firmness, glow, and resilience. But, when training stress piles up (and sleep or nutrition don’t keep the same pace), cortisol can stay elevated. This can increase inflammation in the body and break down collagen, the protein that keeps skin firm and smooth. 

Worth checking: 

• Cortisol levels – chronic elevation can drive inflammation, thin skin, and accelerate ageing 
• Thyroid hormones (TSH, FT3, FT4) – imbalance affects energy, skin texture, and moisture 

 

2. Cutting calories? Your skin’s not a fan
 

For some people, reducing calorie intake is important for reaching a healthy weight or fitness goal. But if you’re under-fuelling, your body can go into conservation mode. That can mean hormone shifts, slower thyroid function, and dry, dull, or slow-healing skin [1]. 

 Your skin needs more than just protein and carbs – think vitamins, minerals, and healthy fats. Iron, vitamin A, zinc, omega-3s, and a rainbow of fruit and veg all help your skin stay strong, smooth, and clear. 

Worth checking: 

• Vitamin B12 and folate – essential for cell turnover and healing 
• Ferritin – low levels can make skin look pale or tired 
• Thyroid profile – metabolism and skin repair are closely linked 

 

3. Supplements and skin side effects
 

Creatine, pre-workouts, whey... great for gains, not always great for your face. Some boost oil production [2], others upset your gut or immune system. If your skin changed after starting a new supplement stack, it's worth checking in on key nutrients and inflammation markers. 

Rather than guessing, test how your body is responding – and make sure you’re supporting your system, not just pushing it. 

Worth checking:  

• Vitamin D – aim for >75 nmol/L for immune and skin health 
• Omega-3 index – helps reduce inflammation and dryness 

4. Sweat, gear, and hygiene habits
 

You might be disciplined with your workouts, but are you as strict with your skincare?  

Gym hygiene isn’t glamorous, but it matters. Sweaty kit, shared equipment, and old towels are breeding grounds for breakouts. If you’re breaking out on your back, shoulders, or chest, hygiene could be the issue, not your hormones [3]. 

If your workouts are causing you to sweat more than average, then also remember to stay hydrated - sports drinks can take you so far, but water is really your friend here.  

Top tip: 

• Rinse off after sessions, use breathable fabrics, and rotate your kit. 

 

5. Macros? Nailed. Micros? Maybe not.
 

Even the fittest people can have nutrient deficiencies. Training increases your need for antioxidants, minerals, and fats that support your skin barrier. While peanut butter is great to meet your protein goals, it isn't going to deliver all of the nutrients you need. 

Low intake or poor absorption (often caused by gut stress) can leave your skin dry, blotchy, or inflamed [4]. 

Worth checking: 

• Vitamin D – low levels are linked to acne and poor immunity 
• Zinc and magnesium – calm inflammation and speed healing 
• B12, folate, and iron support cell turnover and oxygen delivery 
• Omega-3s – reduce dryness and help with inflammatory conditions 

 

6. Gut stress = skin stress
 

Hard training hits your gut too. If recovery or nutrition are off, inflammation goes up – and your skin shows it. Combined with stress or restrictive diets, this can increase systemic inflammation and affect your skin [5]. 

Eat foods that support your gut health, not harm it. Fruits, vegetables, whole grains, and fermented foods. Stress can also play havoc on your gut, so give your body proper recovery windows. 

Worth checking: 

• hs-CRP – systemic inflammation marker 
• Omega-3 index – linked to anti-inflammatory effects 

 

7. Happy liver, happy skin
 

Your liver is the body’s main detox centre, it filters out waste, processes hormones, and supports skin health. But high alcohol intake, excess saturated fat, or a sedentary lifestyle can lead to liver stress or fatty liver disease. 

 In more advanced stages, this can lead to skin issues like bruising, yellowing (jaundice), and persistent itchiness. Liver function tests offer a helpful snapshot, though they may still appear normal in early liver disease. 

Worth checking: 

• ALT, GGT – raised levels can suggest liver stress 
• Bilirubin – may relate to jaundice and toxin build-up 

8. Hydration is key
 

Dehydrated skin looks dull, dry, and less elastic, even if the rest of your health habits are spot on. Kidney markers like urea and creatinine can hint at dehydration, but monitoring how much you drink, your thirst, and colour of your urine are usually more reliable indicators.  

Hydration matters for skin cell health, circulation, and healing, so aim for regular water, not just energy drinks. 

Worth checking:  

• Urea and creatinine – dehydration can push these up 
• Electrolytes – sodium and potassium support hydration and muscle recovery 

Your skin shouldn’t suffer for your fitness
 

If you’re doing all the right things for your health and your skin’s still not happy, a blood test can help you get smarter. It looks at hormone balance, recovery, nutrient gaps, inflammation, and more – to spot what’s holding you back. 

You train hard. You eat well. So why is your skin holding you back?  

A blood test takes the guesswork out, helping you fix the root cause of breakouts, dryness, or irritation. 

 

---

References 

1. Redman LM, Ravussin E. Caloric restriction in humans: impact on physiological, psychological, and behavioral outcomes. Antioxid Redox Signal. 2011;14(2):275–287.
2. Silverberg NB. Diet and acne: examining the evidence. Skin Therapy Lett. 2012;17(5):1–3.
3. Dreno B, Pecastaings S, Corvec S, Veraldi S, Khammari A, Roques C. Cutibacterium acnes (Propionibacterium acnes) and acne vulgaris: a brief look at the latest updates. J Eur Acad Dermatol Venereol. 2018;32(S2):5–14.
4. Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866.
5. Salem I, Ramser A, Isham N, Ghannoum MA. The gut microbiome as a major regulator of the gut-skin axis. Front Microbiol. 2018;9:1459.
6. Rabe JH, Mamelak AJ, McElgunn PJ, Morison WL, Sauder DN. Photoaging: mechanisms and repair. J Am Acad Dermatol. 2006;55(1):1–19.