Is Sugar Bad For Muscle Growth?

Is sugar bad for muscle growth

Sugar is a commonly misunderstood substance in the athletic and bodybuilding worlds. Some athletes and bodybuilders believe you have to have it to build muscle, and others say you do not need it for muscle growth. So who is right? Is sugar bad for muscle growth? Let’s find out and see what the science says.

What is sugar?

Sugar is a crystalline, white carbohydrate and is a sweetener and preservative. Sugar is a refined form of carbohydrates that dissolves quickly. Sugar has become controversial in the athletic and bodybuilding world. Even though sugar can provide a quick and easy form of instant energy for the body, it has significant downsides, such as it can cause diabetes and obesity. Many athletes and bodybuilders use sugar post-workout. Since it has negatives and some positives, what is the answer? Is sugar bad for muscle growth? or is sugar good for muscle growth? 

How many different types of sugar are there?

The tricky part about sugar today is that it is everywhere in our food. Often it is hidden in the food we eat, and we do not even realize it. Food producers have come up with many different names for sugar, and currently, sugar appears on labels of food products under 60 different names. Because of this hidden sugar, people often think they are eating sugar-free diets when, in fact, they are consuming sugar just under another name.

Below is a table that lists all the different names for sugar.

Agave NectarBarbados SugarBarley maltBeet sugarBlackstrap molassesBrown rice syrup
Brown sugarButtered sugarButtered syrupCane juice crystalsCane juiceCane sugar
CaramelCarob syrupCaster sugarCoconut sugarCorn sweetenerCorn syrup
Corn syrup solidsCrystalline fructoseDate SugarDemara sugarDextranDiastatic malt
DiataseEthyl maltolEvaporated cane juiceFructoseFruit juice concentrateGalactose
Golden sugarGolden syrupGrape sugarHigh fructose corn syrupHoneyInvert sugar
Icing sugarLactoseMalt syrupMalt syrupMaltodextrinMaltose
Maple syrupMolasses syrupMuscovado sugarorganic raw sugarOat syrupPanela
PanochaConfectioner’s sugarRice bran syrupRice syrupSorghumSorghum syrup
SucroseSugarYellow sugarTreacleTapioca SyrupTurbinado sugar
Table showing the 60 different names for sugar
Image showing the 60 different names for sugar
Image showing the 60 different names for sugar

Is sugar bad for muscle growth?

Sugar is not in and of itself bad for muscle growth, but indirectly it can cause poor health and disease that can, over time, negatively impact your ability to train and workout, and this will hurt your muscle growth. 

We could not find any scientific studies that showed a negative correlation between sugar intake and muscle growth. In fact, we found the opposite that increasing sugar intake at specific times such as intra-workout or post-workout can increase the anabolic environment and lead to increased muscle growth.[1]

Since acute sugar consumption does not hinder muscle building and actually improves muscle building, let’s look at chronic sugar intake and if it is bad for muscle growth. It is common knowledge that chronic consumption of large amounts of sugar will lead to type two diabetes. But what is often not mentioned is the insulin resistance that comes before the diagnosis of diabetes. It is insulin resistance that is most detrimental to us looking to build muscle mass. If your body is resistant to its insulin, it will not react the same way it used to, to the insulin. This resistance means that the insulin will be less effective at shuttling glucose and amino acids into the muscle cells. If the muscle cells get less glucose and amino acids, they will be less effective at building new muscle. Studies have demonstrated that those who have diabetes have a higher rate of muscle atrophy.[2] 

A fascinating study that we found demonstrated that high glucose levels could reduce testosterone levels. As we all know, if your testosterone is low, this will significantly hinder your ability to build muscle.[8]

Is sugar good for muscle growth?

Sugar is good for muscle growth when used in a planned and timed manner. You should not just consume large amounts of sugar all day or whenever you want, as this will lead to obesity, insulin resistance and diabetes over the long term. As we mentioned above, becoming insulin resistant or diabetic can greatly hinder building muscle. Instead, studies have demonstrated that you should use sugar in and around training and workouts. More specifically, you should consume sugar intra-workout and post-workout.[7] Numerous studies show that adding glucose to your protein shake can significantly increase its anabolic ability and ultimately muscle growth.[9]

Summary if sugar is bad for building muscle

Sugar is a complex nutrient and should be used sparingly and in a calculated way at specified times, such as intra-workout and post-workout. It is also essential to know that there is no such thing as an essential carbohydrate! You can survive and thrive indefinitely by never consuming another carbohydrate or sugar for the rest of your life. However, you have to consume essential fats and amino acids or else you will die in a short period.

Our society has convinced people that carbohydrates and sugar are part of a balanced diet when, in fact, they are entirely optional. Many athletes will say, wait a minute, I need carbs and sugar post-workout to get the best anabolic response and recovery because insulin won’t be secreted without it. Glucose and amino acids won’t be shuttled into the muscle cells.

Little do they know there are amino acids like leucine, isoleucine, and valine that have been shown to stimulate insulin slightly. Even without insulin, the branched-chain amino acids have been shown to increase glucose uptake into the muscle cells. So in part, you could reduce or eliminate your post-workout carbohydrates and replace them with a BCAA supplement and get a near equivalent effect.[3][4][5][6]


  1. Influence of weight training exercise and modification of hormonal response on skeletal muscle growth – PubMed (
  2. Frontiers | Human Skeletal Muscle Disuse Atrophy: Effects on Muscle Protein Synthesis, Breakdown, and Insulin Resistance—A Qualitative Review | Physiology (
  3. Effects of isoleucine on glucose uptake through the enhancement of muscular membrane concentrations of GLUT1 and GLUT4 and intestinal membrane concentrations of Na+/glucose co-transporter 1 (SGLT-1) and GLUT2 | British Journal of Nutrition | Cambridge Core
  4. Effects of Leucine and Isoleucine Infused Intrapancreatically on Glucagon and Insulin Secretion | Endocrinology | Oxford Academic (
  5. Leucine Stimulates Insulin Secretion via Down-regulation of Surface Expression of Adrenergic α2A Receptor through the mTOR (Mammalian Target of Rapamycin) Pathway (
  6. Leucine metabolism in regulation of insulin secretion from pancreatic beta cells (
  7. Effects of Supplement-Timing and Resistance Exercise on Skeletal Muscle Hypertrophy | VU Research Repository | Victoria University | Melbourne Australia
  8. High glucose levels reduce testosterone production (
  9. The combined effect of whey, creatine and glucose (

The information contained within this article is not intended to be taken as medical of dietary advice. You should consult with your family doctor before undertaking any changes to your diet or supplements.