Nutrition · Training · Jun 27, 2025

Why Sugar is Optimal Post-Workout: Recovery, Refueling, and Protein Synthesis

Sugar gets a bad rap and in a sedentary population, that’s fair - reduced sugar intake there is wise. But after training, it’s a very different story because in the post-workout window, sugar is a natural, highly effective recovery tool—refilling energy stores, boosting muscle repair, and supporting adaptation

Used smartly, sugar beats maltodextrin and all other UPF carbs hands down every time. Additionally, a carb source like sugar is essential in all recovery protein products to maximise results - low/no-carb protein products do not allow the body to optimise recovery.

This is all evidence-based and this evidence is why, at 33Fuel, when we need a natural carb source in our protein products, quality sugar always has a place on the team.

Is Sugar Bad After a Workout? Not When You’ve Trained Well

Recovery isn’t passive. It’s when the body works hardest to adapt, rebuild, and get stronger. To do that, it needs three things immediately post-exercise:

Glycogen Replenishment
Protein Synthesis Support
Anabolic Hormonal Activation

Sugar helps with all three – effectively and naturally.

Sugar vs Maltodextrin: Refueling Glycogen Stores

After training, muscles and liver are drained of glycogen. Refilling these stores quickly is essential for performance recovery and immune protection.

Sugar (a 50:50 mix of glucose and fructose) supports:

Muscle glycogen (via glucose)
Liver glycogen (via fructose)
Maltodextrin, being pure glucose, misses this dual effect

Studies show that glucose-fructose blends increase total carbohydrate oxidation and are effective for fueling during and after exercise (1).

Enhancing Protein Absorption with Sugar

Protein post-exercise is critical – but without carbs, its effect can be blunted. Sugar boosts the absorption and effect of your post workout protein as well or better than maltodextrin and other UPF carbohydrates by:

• Increasing blood flow to muscles and gut (2, 3)

• Elevating insulin to shuttle amino acids into cells (2, 3)

• Suppressing muscle protein breakdown post-exercise to help optimise gains from muscle protein synthesis (MPS) (2, 3)

The Anabolic Hormone Advantage

Post-exercise, insulin is our anabolic ally. It supports:

mTOR activation (initiating protein synthesis)
Proteolysis suppression (reducing muscle breakdown)
Net positive protein balance

You don’t need maltodextrin or other UPF carbohydrates to achieve this. Sugar works and does it without the negative UPF baggage maltodextrin and co carry. Studies show even modest insulin increases (from natural sugar) post-workout promote muscle growth. (4)

Why Maltodextrin (and others) Fall Short

Maltodextrin and other UPF carbohydrates like it are used so often in sports nutrition due to their convenience for manufacturers, not for their performance value to athletes and consumers.

They're cheap, bland, and shelf-stable.
They're ultra-processed (NOVA Group 4).
Maltodextrin has a higher GI than sugar (GI 95–136).
And is linked to gut dysbiosis, insulin spikes, and blood sugar volatility (5)

Maltodextrin and the ‘Sugar-Free’ Loophole

On nutritional labels maltodextrin is allowed to be classed as a ‘carbohydrate’, instead of as a ‘sugar’ This allows ‘sugar-free’ claims, even though it:

Spikes blood sugar faster than table sugar
Causes greater glycaemic volatility
Disrupts gut bacteria and mucosal barriers

Real Sugar, Real Recovery Benefits

When sourced naturally – quality sources like light brown cane sugar, or coconut palm sugar – can also provide:

Trace minerals (magnesium, potassium)
Polyphenols and antioxidants
Superior taste, improving consistency and compliance. Taste matters. If it’s enjoyable, you’ll actually use it – helping ensure full recovery.

The Science Says: Sugar Works

Glucose-fructose blends (like sugar - 50% Glucose, 50% Fructose) are as effective as maltodextrin for muscle glycogen, and superior for liver glycogen (Jentjens & Jeukendrup, 2005) (1)
Consuming carbohydrate as sugar with protein post exercise can suppress muscle protein breakdown to help optimise muscle protein synthesis (2), (3)
Modest insulin increases (from natural sugar) post-workout promote anabolic responses (4)

Final Takeaway: Rethink the Role of Sugar in Recovery

Used intelligently, sugar is:

Effective at refueling muscle and liver glycogen
Essential for opimtising protein’s effect
Safer and more natural than synthetic UPF alternatives

Used during or after sport, sugar is natural targeted high performance nutrition. And being natural, you avoid the downsides of maltodextrin and ultra-processing (UPF) entirely.

References

(1) Jentjens RL, Jeukendrup AE. High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. Link

(2) Børsheim et al, Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exercise. Link

(3) Poole et al, The Role of Post-Exercise Nutrient Administration on Muscle Protein Synthesis and Glycogen Synthesis. Link

(4) Greenhaff et al, The influence of insulin and amino acid supply on muscle protein synthesis in man. Link

(5) Chassaing B, et al. Dietary emulsifiers directly alter human microbiota composition and gene expression ex vivo. Gastroenterology. Link