Intra-workout nutrition – is it really necessary?

Introduction

You’ve warmed up, you’re focused, and your workout is underway. But while you train, things are happening inside your body that most people never think about – and this is exactly where intra-workout nutrition makes the difference between a good session and a truly great one.

In this guide, we dive into the science behind intra-workout nutrition, what you actually need, how to build your stack – and the most common mistakes to avoid.

What happens in the body during training?

During an intense session, muscles consume glycogen (stored energy from carbohydrates) at a rapid pace. At the same time, muscle protein is broken down – a natural process called catabolism. The body sweats, electrolytes are lost, and blood flow is prioritized toward working muscles.

On a molecular level, AMPK (an enzyme signaling energy deficit) is activated, and mTOR signaling is temporarily inhibited. This means the body prioritizes energy production over muscle building. The right nutrition during your session can counteract this and keep the body in a more anabolic state.

The three pillars of intra-workout nutrition

1. Fast-acting carbohydrates – the fuel that keeps you going

During longer or more intense sessions (45+ minutes), glycogen stores begin to deplete. Fast-acting carbohydrates – like cyclic dextrin or maltodextrin – are absorbed quickly without straining the digestive system and replenish energy stores in real time.

Cyclic dextrin has a particularly low osmolality, meaning it passes through the stomach quickly and provides stable energy without blood sugar spikes. Maltodextrin is a more affordable alternative with a similar effect.

What it does: Maintains intensity, prevents energy crashes, and protects muscle mass.

→ Explore CarbUP – our fast-acting carbohydrates

2. Amino acids (EAA/BCAA) – protect and build

Essential amino acids (EAA) – and particularly branched-chain amino acids (BCAA) like leucine, isoleucine, and valine – reduce muscle catabolism during a session. Leucine is especially important as it activates mTOR, the body’s primary signaling pathway for muscle protein synthesis.

Research shows that ingesting EAA during training can increase muscle protein synthesis by up to 50% compared to training without amino acids. For the best effect, a complete EAA spectrum is recommended rather than just BCAA.

What it does: Reduces muscle breakdown, supports recovery, and can improve endurance.

→ Explore IntraUP – our intra-workout amino acids

3. Hydration and electrolytes – more than just water

Even at 2% fluid loss, performance drops noticeably – reaction time, strength, and endurance are all negatively affected. But water isn't enough – sodium, potassium, and magnesium are crucial for muscle contraction, nerve function, and fluid balance at the cellular level.

Sodium is particularly important as it regulates fluid balance and helps the body actually absorb and retain water. Without enough sodium, you risk drinking plenty but still becoming dehydrated at the cellular level.

What it does: Prevents cramps, keeps focus sharp, and optimizes the muscle's ability to work.

→ Explore HydraUP – our electrolytes

Training-specific recommendations

Strength training

Focus: amino acids and moderate carbohydrates. For sessions under 60 minutes, 5–10g of EAA and electrolytes are often enough. For longer strength sessions or high volume, add 20–30g of fast-acting carbohydrates.

Endurance training (running, cycling)

Focus: carbohydrates and hydration. The body consumes glycogen at a much higher rate. Aim for 30–60g of carbohydrates per hour and drink 500–750ml of fluid with electrolytes per hour.

HIIT and CrossFit

Focus: everything above. High intensity combined with varied movement patterns requires fast energy, muscle protection, and aggressive hydration. A complete intra-workout formula is most justified here.

How to build your intra-workout stack

An effective intra-workout drink doesn't need to be complicated. Focus on:

• Carbohydrates: 20–40g of fast-acting carbohydrates per hour depending on intensity
• EAA/BCAA: 5–10g for muscle protection
• Electrolytes: Sodium, potassium, and magnesium in balanced amounts
• Water: At least 400–600ml per hour

Example of a simple stack:
– 20g CarbUP
– 8g IntraUP
– HydraUP electrolyte powder
– 500ml water

Or take the shortcut with our ready-made Intra & Post Stack – everything you need in one package.

Mix in a shaker and sip continuously during the session – not all at once.

Common mistakes to avoid

• Waiting too long: Start drinking your intra-workout early in the session, not when you already feel tired.
• Only BCAA: BCAA without other EAA does not provide full muscle protein synthesis. Choose a complete EAA spectrum.
• Ignoring sodium: Without sodium, the body does not absorb water effectively. Electrolytes are not optional.
• Too much sugar: Simple sugars can cause blood sugar spikes and crashes. Choose carbohydrates with low osmolality like cyclic dextrin.
• Same stack regardless of session: Adjust the amount of carbohydrates and amino acids based on session type and length.

Frequently asked questions (FAQ)

Do I need intra-workout if I train in the morning?
Yes, especially if you train fasted. Without food since the night before, glycogen stores are already lower and muscle catabolism is higher. EAA and electrolytes are extra important here.

Can I use protein instead of EAA?
Protein works but is absorbed more slowly. During training, rapidly available amino acids (EAA) are more effective than a complete protein powder.

How does intra-workout differ from pre-workout?
Pre-workout focuses on preparing the body – energy, focus, and pump. Intra-workout focuses on maintaining performance and protecting muscles during the session. They complement each other.

Is it okay to skip intra-workout sometimes?
Absolutely. For shorter or lighter sessions, it is not necessary. But for hard training, competition preparation, or if you notice your energy dropping mid-session – then it is worth prioritizing.

Conclusion

Intra-workout nutrition isn't a trick – it’s science. The right fuel at the right time allows you to train harder, recover faster, and consistently perform at your peak. It is the difference between surviving the workout and owning it.

Want to know more about specific ingredients like cyclic dextrin or EAA? Explore our ingredient guides for further reading.