Common Sports Nutrition Mistakes That Could Be Holding You Back

Whether you're training for your first 5K, preparing for a marathon, competing in HYROX, lifting weights in the gym or simply trying to improve your fitness, your nutrition plays a vital role in your performance. Even with a well-structured training programme, common sports nutrition mistakes can limit your progress, reduce energy levels and slow recovery.

Many athletes focus heavily on training but overlook how important it is to fuel their body properly. Under-fuelling, poor hydration, inconsistent meal timing and relying on supplements instead of a balanced diet are just a few examples of habits that can hold you back.

At Nutrition & Co, our registered sports dietitians work with athletes and active individuals of all abilities to optimise performance through personalised nutrition advice. In this guide, we'll explore the most common sports nutrition mistakes, explain why they matter and provide practical, evidence-based tips to help you get the most from your training.

Why Sports Nutrition Matters and what are common sports nutrition mistakes.

Good nutrition is about much more than calories. The foods and fluids you consume influence almost every aspect of athletic performance, including:

• Energy levels

• Strength and power

• Endurance

• Muscle recovery

• Immune function

• Injury risk

• Concentration

• Sleep quality

• Adaptation to training

When nutrition is matched to your training demands, you're more likely to recover well, adapt positively to exercise and consistently perform at your best.

Mistake 1: Not Eating Enough Overall

One of the biggest mistakes we see is athletes simply not eating enough.

Many people are trying to improve performance while also losing weight or eating "clean". Unfortunately, restricting energy intake too much can leave your body without enough fuel to support both daily life and exercise.

Low energy availability can lead to:

• Persistent fatigue

• Poor recovery

• Reduced performance

• Frequent illness

• Increased injury risk

• Loss of muscle mass

• Hormonal disruption

• Reduced bone health

This is particularly common among endurance athletes, runners and those training multiple times per week.

Dietitian Tip

Rather than focusing solely on weight, aim to fuel appropriately for your training load. If your energy levels are consistently low or your performance has plateaued, it may be worth reviewing your overall energy intake with a sports dietitian.

Mistake 2: Not Eating Enough Carbohydrates

Carbohydrates often receive a bad reputation, but for athletes they remain the body's preferred fuel source during moderate and high-intensity exercise.

When carbohydrate stores become depleted, you may notice:

• Heavy legs

• Early fatigue

• Slower running pace

• Reduced power output

• Poor concentration

• Longer recovery times

Good carbohydrate sources include:

• Oats

• Rice

• Pasta

• Potatoes

• Wholegrain bread

• Fruit

• Breakfast cereals

• Wraps

• Couscous

Carbohydrate requirements vary depending on your training volume, intensity and goals. Someone training for a marathon or HYROX will typically require more carbohydrates than someone exercising recreationally twice per week.

Mistake 3: Skipping Meals Before Training

Many people exercise first thing in the morning or train after work without eating beforehand.

Although fasted training may be appropriate in certain situations, regularly training without enough fuel can reduce training quality and make sessions feel much harder than necessary.

Signs you may need to eat before training include:

• Feeling dizzy

• Poor concentration

• Running out of energy quickly

• Reduced power

• Feeling unusually tired

Good Pre-Exercise Snacks

• Banana

• Toast with jam

• Rice cakes

• Bagel

• Fruit smoothie

• Low-fat yoghurt

• Cereal bar

Aim to experiment during training rather than trying something new before a race or competition.

Mistake 4: Forgetting Recovery Nutrition

The work doesn't stop when training ends.

Recovery nutrition supports:

• Muscle repair

• Glycogen replenishment

• Reduced soreness

• Adaptation to training

Many athletes delay eating for several hours after finishing exercise, particularly after evening sessions.

Ideally, aim to eat within approximately one hour of longer or higher-intensity training sessions.

A balanced recovery meal should contain:

• Carbohydrates

• Protein

• Fluids

Examples include:

• Chicken and rice

• Greek yoghurt with fruit

• Beans on toast

• Tuna pasta

• Smoothie with milk and fruit

Mistake 5: Prioritising Protein While Ignoring Everything Else

Protein has become incredibly popular in recent years.

Although protein is essential for muscle repair and growth, more isn't always better.

Many athletes consume large amounts of protein while neglecting carbohydrates, healthy fats and overall energy intake.

Instead, focus on a balanced eating pattern that includes:

• Protein

• Carbohydrates

• Healthy fats

• Fruit

• Vegetables

• Dairy or fortified alternatives

Protein works best as part of an overall balanced diet.

Mistake 6: Poor Hydration

Even mild dehydration can negatively affect performance.

Sweat losses vary considerably between individuals and depend on:

• Exercise intensity

• Duration

• Temperature

• Humidity

• Individual sweat rate

Common signs of dehydration include:

• Headaches

• Fatigue

• Muscle cramps

• Dark urine

• Reduced concentration

• Increased heart rate

Practical Hydration Tips

• Drink regularly throughout the day.

• Start exercise well hydrated.

• Replace fluids lost during training.

• Consider electrolytes during prolonged exercise or hot weather.

Mistake 7: Relying Too Heavily on Supplements

Supplements are often marketed as quick fixes for improving performance.

However, most athletes will gain far greater benefits from improving:

• Daily nutrition

• Meal timing

• Hydration

• Recovery

• Sleep

Some supplements may have evidence supporting their use in specific situations, including creatine or caffeine, but they should complement, not replace, a balanced diet.

Always seek advice from a registered sports dietitian before starting supplements, particularly if you compete in organised sport where contamination risks exist.

Mistake 8: Ignoring Meal Timing

It's not just what you eat-it's when you eat.

Long gaps between meals can make it difficult to meet your energy needs and may reduce exercise performance.

Try to spread your intake across the day by including:

• Three balanced meals

• Nutritious snacks if needed

• Protein at regular intervals

• Carbohydrates around training

This approach can help maintain energy levels and support recovery.

Mistake 9: Eating the Same Way Every Day

Training demands often change throughout the week, but eating habits sometimes don't.

For example:

• A long run requires different fuelling to a rest day.

• A double training day requires more energy than a recovery session.

• Competition days require careful planning.

Matching your nutrition to your activity level can help optimise both performance and recovery.

Mistake 10: Copying Someone Else's Nutrition Plan

Social media is full of "What I Eat in a Day" videos and influencer meal plans.

However, nutrition should always be individualised.

Your nutritional needs depend on factors such as:

• Age

• Sex

• Body size

• Goals

• Training load

• Medical conditions

• Food preferences

• Lifestyle

What works for an elite athlete or fitness influencer may not be appropriate for you.

A personalised nutrition plan is far more effective than following generic advice online.

How a Sports Dietitian Can Help

If you're training consistently but not seeing the progress you'd expect, your nutrition could be one of the missing pieces.

A sports dietitian can help you:

• Optimise your energy intake

• Fuel training effectively

• Improve recovery

• Reduce gastrointestinal issues

• Plan race-day nutrition

• Develop sustainable eating habits

• Support body composition goals safely

Whether you're preparing for a marathon, HYROX event, cycling sportive or simply looking to improve your gym performance, personalised nutrition advice can make a significant difference.

At Nutrition & Co, our experienced sports dietitians provide evidence-based, personalised nutrition support for athletes of all levels. Whether you're chasing a personal best, returning from injury or simply looking to feel stronger in your training, we're here to help you fuel your performance with confidence.

Frequently Asked Questions

Should I eat before every workout?

For most moderate to high-intensity sessions, yes. Eating carbohydrates before exercise can help improve energy levels and performance. A banana, toast with jam or a bagel are all good options.

Are protein shakes necessary?

Not usually. Most people can meet their protein needs through a balanced diet. Protein shakes can be a convenient option if you're struggling to get enough protein from food.

What are the signs of poor sports nutrition?

Common signs include low energy, poor recovery, reduced performance, frequent illness and persistent muscle soreness. If these symptoms continue, consider speaking to a sports dietitian.

For personalised advice book an initial appointment with our team today.