Top 5 Nutrition Mistakes Active Athletes Make

When you’re training hard and pushing your limits, what you eat matters just as much as your workouts. But even the most dedicated athletes make common nutrition mistakes that can hold them back.

Whether you're running marathons, hitting the gym, or competing in team sports, avoiding these errors can help you recover faster, feel stronger, and perform at your best.

Here are the top 5 nutrition mistakes active athletes make, and how partnering with a sports dietitian can help you avoid them.

Top nutrition mistakes:

1. Under-fuelling Before and After Workouts

Many athletes don’t eat enough to support their training, especially around workouts. Some skip meals due to time constraints or fear of feeling too full during exercise. Others simply underestimate how much energy their body actually needs.

Why it’s a problem:

• Low energy during workouts

• Increased fatigue and soreness after training

• Muscle breakdown and slow recovery

• Hormonal disruptions (like RED-S in endurance athletes)

  
  

Consistently under-fuelling can impact your progress and long-term health. It’s not just about how much you eat, but when and what.

A sports dietitian can assess your energy needs and help you build a personalised fueling plan that supports performance without overcomplicating your routine.

2. Overusing Supplements Instead of Food

Supplements are everywhere—from protein powders to energy boosters. While they can be helpful in some cases, many athletes rely on them too heavily, often at the expense of real, whole foods.

Common risks:

• Missing out on essential nutrients from whole foods

• Digestive upset or poor absorption

• Consuming unregulated or banned substances

Supplements should fill in gaps—not form the foundation of your diet.

A sports dietitian can help you decide whether supplements are necessary, choose safe options, and prioritise food-first strategies to meet your goals.

3. Poor Hydration and Electrolyte Management

Hydration goes beyond drinking water. When you sweat-especially in long or intense sessions-you lose important electrolytes like sodium, potassium, and magnesium.

Most athletes:

• Don’t drink enough throughout the day

• Forget to hydrate before training

• Rely on water alone during long workouts

Why this matters:

• Dehydration reduces power, focus, and endurance

• Imbalances can cause cramps, fatigue, or nausea

• Overhydration without electrolytes can be just as harmful

A sports dietitian can create a tailored hydration strategy based on your training volume, sweat rate, and climate, keeping your body in balance and your performance sharp.

4. Ignoring Digestive Issues (Especially IBS)

Gut issues are common in athletes, especially runners and endurance athletes. Bloating, cramps, gas, or urgent bathroom trips can seriously disrupt training. But many athletes ignore these symptoms, thinking they’re just “part of the process.”

For athletes with Irritable Bowel Syndrome (IBS), unmanaged symptoms can lead to:

• Missed workouts

• Poor nutrient absorption

• Anxiety around eating or competing

• Unnecessary food restrictions

A sports dietitian trained in gut health and IBS can help you pinpoint triggers, manage symptoms, and still meet your fueling needs. With the right strategy, it’s possible to train hard and eat comfortably.

5. Inconsistent Meal Timing and Planning

Athletes often lead busy lives, balancing training, work, travel, and social commitments. That makes it easy to fall into irregular eating patterns, skip meals, or grab whatever’s convenient.

This can lead to:

• Low blood sugar and energy crashes

• Poor recovery between sessions

• Reliance on fast food or ultra-processed snacks

A sports dietitian can help you build simple, sustainable routines. Whether it’s prepping ahead, planning snacks, or adjusting meals based on your schedule, you’ll fuel smarter and more consistently, with less effort.

What If You Have IBS or Digestive Issues?

Nutrition is even more complex for athletes managing IBS. Exercise, stress, and certain foods can all trigger symptoms. But with expert support, you don’t have to choose between performance and gut comfort.

A sports dietitian specialising in IBS can:

• Identify your food triggers

• Guide you through safe protocols like the low-FODMAP diet

• Keep your energy intake high enough for training

• Help you eat with more confidence and less restriction

Why See a Sports Dietitian?

Generic nutrition advice doesn’t work for every athlete. Your sport, training load, goals, and body are unique, and your nutrition should be, too.

Sports dietitians are trained to:

• Personalise your fueling strategy

• Address performance, recovery, and health goals

• Help manage conditions like IBS, RED-S, and fatigue

• Support you during off-season, competition prep, or injury recovery

• Make meal planning and nutrition simple—even with a busy schedule

FAQs

1. How do I know if I’m under-fuelling?

If you feel tired all the time, can’t recover between sessions, or have lost your period (for females), it may be a sign. A sports dietitian can evaluate your intake and help rebalance your diet.

2. Are supplements necessary for athletes?

Not always. Whole foods can usually cover your needs. Supplements may be helpful in certain situations, but only when used safely and appropriately. A dietitian can guide you based on your specific goals.

3. Can a dietitian help with IBS and athletic training?

Yes! Sports dietitians can help you manage IBS without cutting out too many foods. They’ll work with you to create a plan that supports both gut health and performance.

Maximise your performance by working with our sports nutrition experts at Nutrition and Co to make a personalised plan. Book an initial appointment today on +447888465215 via WhatsApp.