In a previous article on carbohydrates, I covered the general importance of carbs for women athletes.
The article provided context and a conceptual understanding of:
- Why, for female athletes who train with intensity, carbohydrates are a key fuel source and should not be feared.
- Carbohydrates, along with fats, make up the non-protein energy portion of your total energy needs.
- A low carb approach may be efficacious in highly controlled research environments and for certain clinical populations. However, in real-world settings for busy, athletic women who train with intensity, it’s often not the most effective way to fuel.
- Carbohydrate intake for women athletes should be looked at in terms of fueling their strength-related goals, not just from a general nutrition perspective.
In this article, you’ll learn:
Fear of Carbs: How Did We Get Here?
Once upon a time, nutrition (and sports nutrition) was very centered on carbohydrate.
The idea was fat should be minimized. And protein was largely irrelevant. (The recommendations were so low that it was easy to hit them. Protein quality wasn’t as big an emphasis).
That left the focus on carbohydrate.
Additional carbohydrate, mostly in the form of sugar, was added to nearly everything.
Carbohydrate based sports drinks, bars, and gels, designed for endurance athletes, were soon marketed to even the casual exerciser.
But then came the carb backlash.
Atkins, The South Beach Diet, and The Zone Diet were the popular early variations of low-carb eating. Other versions of low carb appeared in the late 2000s and have slowly evolved into a scene largely dominated by keto.
Has the Carb Pendulum Swung Too Far?
One good thing that’s come from the last twenty years or so of nutrition debate and research is a more nuanced and individualized approach to nutrition.
Everyone doesn’t need to eat 60% of their energy as carbohydrate. Everyone also doesn’t need to “go low carb.”
As periodized nutrition has become a better understood and more accepted concept, an individual athlete might fluctuate their carbs depending their goals and training demands. This is a “fuel for the work required” approach.
But fears are built fast and die slow.
It took people a long time to accept the message that they didn’t need to fear fat as much as they did from the 1980s through 2000s. Likewise, I think it’ll take time for women to move past their fears around eating carbohydrates.
My job is to help educate and empower 40+ athletic women to fuel their strength. This includes adding more balance and nuance to the topic of carbohydrate intake. Specifically, how much carbohydrates is appropriate when undertaking regular strength and conditioning training?
Carbohydrates for Weight Lifting
My focus here is very specific to women who undertake regular weight lifting to build muscle and add strength. Recommendations here will be made specific to that context.
Women who do regular endurance training will need recommendations specific to that context.
If you’re an athletic woman who focuses on endurance, please don’t take any of the numbers discussed here and apply them to your fueling strategies. You’ll likely find yourself under-fueling if you do.
Minimum Carb Requirements
There is a certain degree of irony when you hear those in some quarters of common nutrition debates point out that our absolute requirement for carbohydrate is zero.
It’s ironic because many of these same individuals criticize, correctly, the very low RDA for protein (0.8g/kg). They argue that this level of protein intake is the barest minimum an individual should eat whilst avoiding protein energy deficiencies.
It’s an amount that will allow you to survive but not thrive. If you have a goal to train for muscle growth and muscle recovery, you need more than the absolute minimum for protein.
Yet, this is the same argument for eating a minimum amount of carbohydrate.
Reputable and qualified sources of nutrition information support the idea that even though the absolute dietary requirement of carbohydrate to survive (not die) is zero, our goal is not to barely scrape through life.
I know you’re more interested in thriving than barely surviving.
Protein Sparing Effect of Carbs
Glucose and other simple carbs like fructose and galactose are the building blocks of carbohydrates.
The adult brain requires in the order of 140g of glucose per day to keep the hamster spinning on its wheel. Red blood cells require another 40g over and above that.
So, you’re looking at around 180g glucose per day just for these two tissues alone.
In the absence of dietary carbohydrate, the body can make glucose from lactic acid, certain amino acids, and glycerol (the carbon backbone of fat). This process is gluconeogenesis.
Gluconeogenesis can supply around 2mg/kg body weight per minute or ~130g/day.
The difference between essential glucose requirements and supply from gluconeogenesis is about 50g/day (180g minus 130g). This could be said to be the absolute minimum requirement of carbohydrate.
If you strength train, consuming enough carbs for muscle building is important. Another way to say this is that carbohydrates are “protein sparing.” This means carbs are used to fuel your training, while protein is used to repair and build new muscle tissue.
As I’ve discussed in the previous article on Carbohydrates for Women Athletes, not increasing dietary protein and fat to ensure energy balance while running your carbohydrate intake this low is a problem.
Adequate fueling goes beyond absolute minimum levels, so I tend to start with a more realistic starting point of around 130 grams of carbs per day.
Carbohydrates and the Menstrual Cycle
Many sports nutrition recommendations for athletic females are based on generally accepted principles such as total energy intake being a top priority. In other words, you must eat enough to avoid low energy availability (LEA).
Also, carb needs will increase as the length and intensity of training or competitions increases.
What about sex-specific considerations?
Research indicates that during the menstrual cycle, there appear to be differences in fuel usage between the follicular and luteal phases. (1)
For example, in the follicular phase, carbohydrate oxidation is greater than in the luteal phase.
This, along with other factors, may influence strategies carbohydrate loading for endurance sports. (2) A review of that topic is outside the scope of this article.
Suffice to say, due to the relative lack of studies on menstruating and female athletes, more studies are needed in this area. (3)
In many athletic women – particularly in the menopause transition and beyond – the issue I see with carbs is two fold:
- Cutting cut back too hard on carbs as part of dieting to address body dissatisfaction leading to large energy deficits. These large deficits can lead to LEA, RED-S, and even accelerate muscle loss.
- Eating more simple carb + fat-dense foods and/or increasing alcohol consumption to cope with stress which leads to large energy surpluses. This can lead to further gains in body fat.
Carbs for Strength Training
As with protein, the field of sports nutrition has departed from calculating carbohydrate requirements as a percentage of total energy.
Instead it focuses on determining requirements based on body weight (grams per kilogram body weight – g/kg BW).
This approach allows for a lot of flexibility when individualizing nutrition plans.
- For example, the International Society of Sports Nutrition (ISSN) recommends a carbohydrate intake of 3-5g/kg BW/day for general physical activity of 30-60 minutes per day, 3-4 days per week. (4)
- The International Olympic Committee (IOC) also uses 3-5g/kg BW/day as a baseline amount of carbohydrate.
- The IOC recommends 4-7g/kg BW/day for strength training athletes.
- Precision Nutrition recommends up to 3.5g/kg BW/day for ‘regular people’ undertaking little or only light activities, and that strength athletes eat in the range of 3.5-5.5g/kg BW/day.
- Dr Stacy Sims recommends women start in the range of 2.5-3.5g/kg BW/day.
So you can see quite a range of recommendations, but all circling very similar ranges.
I also recommend the athletic women I coach have a minimum 2.5g/kg BW/day, especially if they’re coming off the back of an extended period of low carb eating.
For a 70kg female athlete, this is a daily baseline intake of 175g per day, only 45g more carbohydrate than the absolute minimum of 130g/day.
Quantity can absolutely rise depending on frequency, intensity and duration of training.
Fine Tuning Carbs for Weight Training
Depending on their specific context, many women will need more than this, of course. Using g/kg BW/day allows for a significant amount of fine-tuning.
For example, using 0.5g/kg increments for our 70kg athletic woman, allow fine-tuning carbohydrate intake if required.
Again, I don’t recommend calculating carbohydrate, or any other macronutrient for that matter, by starting with a total energy intake number and splitting it based on percentages of each macronutrient.
Random internet TDEE calculators may vary widely in their recommendations. Worse, many athletic women will start with low numbers such as 1200-1500 kcal.
For example, let’s say a woman athlete started with 1200 kcal as her energy intake. (She might need double that in reality.)
Then, she calculates her carbohydrate needs at 40% of this total. That means she’s trying to fuel on a maximum of 120g of carbohydrate per day. This is below the minimum most active women need to fuel their training.
When your macronutrient intake is sufficient, total energy requirements will be met.
You Eat Food, Not Macronutrients
It can be tempting to turn the building of a strong nutritional foundation into a quick math equation. Calculate your ‘numbers’ and call it good, right?
Except, you don’t eat numbers.
Those numbers need to be converted to foods. Foods are put together to make meals meals. And those meals need to be planned and prepped.
Good structures, systems, and schedules are necessary for food prep and getting regular meals. These structures mean adequate fueling can be repeated easily and consistently.
Your life is busy. With so many things going on, don’t underestimate how long it takes to build the structures and systems for solid nutrition to happen largely on autopilot.
I often see the woman I coach slowly slip back from foundational nutrition over time. It can be subtle at first, but progressively, what you think you’re eating and what you’re actually eating can become two quite different things.
Building up a strong nutrition foundation means checking in that you’re eating enough protein, fiber-rich vegetables, carbohydrates, and fats. And it also means looking for opportunities to improve quality as your knowledge, budgets, and skills allow.
Changing your habits, systems, and structure isn’t easy. It takes time, but you can speed up the process with coaching and support.
First, focus on eating enough. After that, focus on eating better.
Rinse and repeat until you have optimized your plan to suit you and your context.
For some people, this optimization might occur quite quickly. For others it can be slow progress over several weeks and months.
But this slow and steady progress beats boom and bust cycles of perfection quickly followed by quitting.
Carbs for Strength Training Sessions
Over and above a solid base diet, do individual strength sessions need their own specific pre-workout fueling?
The short answer here is that it depends on several factors.
It depends on:
- how often you’re training
- whether there are multiple sessions in a day
- the duration and intensity of each of these sessions
- what your nutrition has been like in the hours prior to training.
For example, is it an early morning session coming off an overnight fast? Did that Zoom meeting go long and you didn’t eat lunch?
The literature in this area generally suggests that a carbohydrate intake in the range of 3-7g/kg BW/day is sufficient to prevent glycogen depletion and facilitate performance and adaptation to the training. (5)
The same literature also suggests that diets much lower in carbohydrate and any glycogen depletion “may not be detrimental to acute resistance exercise performance or the cellular signaling activity responsible for adaptation”.
While resistance training does moderately deplete muscle glycogen (relative to endurance training) “the provision of pre-exercise carbohydrate to individuals performing resistance-style exercise in a moderately glycogen depleted state may not have an ergogenic effect.” (4)
Before you get excited, this is where we come back to understanding the difference between efficacy and effectiveness.
Research vs Real Life
Efficacy refers to the degree to which an intervention has a measurable effect under ideal conditions.
Effectiveness refers to the degree to which an intervention has a measurable effect under real-world conditions.
Training in a low glycogen state in a research setting isn’t exactly the real world conditions the majority of the women experience.
And more often than not, the subjects of such studies will be young males.
Additionally, these studies often take place under controlled conditions, with participants using machines to measure output, which can lead to different results than if they were using free weights or other forms of resistance training.
You might go into the lab and perform your sessions in a fed and glycogen replete state, with a researcher or lab technician watching over the session.
This can be a major limitation of such studies, as they don’t exactly replicate a real-world scenario.
Then you might repeat this in a fasted or depleted state, with someone watching over you.
(Your competitive streak might kick in and you’d push to perform well no matter the conditions.)
What Happens After Training When You’re Carb Depleted?
What happens after the testing is done, though? Would you crawl out of the lab on your hands and knees after the testing?
Maybe you’d yell at your kids or partner because you’re tired. Or perhaps, you’d burst into tears for no apparent reason. Would training in a depleted state lead you to binge at night when everyone goes to sleep?
All that mattered for the study’s sake is if you could perform under these controlled conditions, the same way, no matter whether you’d eaten carbohydrates or not. All that mattered was that, over the short period such studies occur over, your cellular signaling for adaptation wasn’t affected.
Ultimately, research done in a low glycogen state can provide valuable insight, but the results must be interpreted with caution because it isn’t the real world.
If you’ve tried squatting heavy with absolutely nothing in the tank, you know it doesn’t feel great. And then after the gym, you have to go about the rest of your day feeling depleted with no sustainable energy.
Do I Even Need Carbs If I Lift Weights?
I hear this question constantly from athletic women over 40.
You want to know, “What about ketogenic diets? Is there something special about these that means I can have my (keto) cake and eat it too when it comes to building strength, power, and muscle?”
Again, it depends on what your goals are.
I work with women specifically to help them build strength and muscle tissue. In many instances, the women athletes I work with need to prioritize muscle gain, building up their lean body mass. This goal requires a small energy surplus.
Ketogenic diet restricts daily carbohydrates, replacing most of the reduced energy with fat, while maintaining an adequate quantity of protein. This is where things get tricky.
As discussed in the previous carb article, replacing all the carbohydrate calories with fat calories is difficult for many women.
Keto and Weight Training for Women?
The research on ketogenic diets and strength training shows a mixed picture of either being able to maintain muscle mass while losing fat-mass, (6) or decreasing muscle mass and performance (7) unless an energy surplus is generated (6) while on such a diet. And if an energy surplus is generated, then body fat loss is less likely to occur.
The research on ketogenic diets in relation to strength training, while having some utility in specific contexts, doesn’t exactly offer ringing endorsements as the optimal way to go, especially for women athletes:
“…Some studies suggest that [a ketogenic diet] might impair resistance training-induced muscle hypertrophy, sometimes with concomitant decrements in muscle performance, at least when expressed in absolute units and not relative to total body mass (e.g., one-repetition maximum). [A ketogenic diet] might therefore be a beneficial strategy for promoting fat loss, although it might not be a recommendable option to gain muscle mass and strength/power.” (7)
“Ketogenic diets, taking into account the possible side effects, can be an alternative for increasing muscle mass as long as energy surplus is generated; (6) however, their application for eight weeks or more without interruption does not seem to be the best option due to the satiety and lack of adherence generated.”
Findings indicate that a [a ketogenic diet] may help to decrease fat mass and maintain fat-free mass after eight 8 weeks of RT in trained-women but is suboptimal for increasing fat-free mass. (6)
Suboptimal. Again, there’s the clash between efficacy and effectiveness.
The Real World Takeaway?
Higher carbohydrate diets (relative to high fat diets) are, for the vast majority of people, much easier to plan and manage when it comes to the real world. They offer a much wider range of foods and far fewer restrictions.
Higher carb intakes are easier to do, and yet many athletes, especially female athletes, tend to under-eat despite reporting ‘best practices’ of carbohydrate intake.
You can only imagine what is likely to happen on very low carb diets, which, even in research settings, are difficult to adhere to and eat enough on.
A relatively recent systematic review on the effect of carbohydrate intake on strength and resistance training performance (8) showed a very mixed bag of evidence. But in the end, the researchers fell on the side of recommending a small amount of carbohydrate (and protein) peri-workout.
The lead author of this review offered a useful plain-English recommendation:
There’s reasonable evidence that fasted training is suboptimal, so we advise that you consume at least 15 grams of (net) carbohydrate and 0.3 g/kg protein within 3 hours of starting your weight lifting sessions. Higher carbohydrate intakes [1.2g/kg/hour] may be beneficial if you train twice a day with high volumes or you do over 10 sets per muscle group per workout.
Carbs for Strength Training Summary
Let’s wrap up the issue of how much carbohydrate is recommended for women athletes doing regular strength training.
- Start by building a good base intake of healthy carbs of at least 2.5g/kg BW per day. For a 70kg person, this is a starting point of ~175g per day.
- If you’re training regularly (3-4 times per week) for 60-90 minutes per session, adequate base intake should be enough to fuel the majority of these sessions.
- Consuming at least 15g of carbohydrate prior to a training session won’t do any harm and may provide some benefit, especially for morning sessions.
- Away from training, focus on mixed macronutrient meals that include protein, complex carbs, fiber and fat. The closer you get to training, focus more on simple carbs with minimal fiber.
- Complex carbohydrates include plant based whole grains; beans and legumes; and fiber-rich fruits and veggies. Athletic women over 40 should focus the majority of your carb intake on these sources and less on simple, refined carbs.
- If you’re training twice a day, or your strength sessions are extensive (more than 10 sets per muscle group per workout), consider adding 1.2g carbs / kg BW per hour of training.
1 Wohlgemuth, K.J., Arieta, L.R., Brewer, G.J. et al. Sex differences and considerations for female specific nutritional strategies: a narrative review. J Int Soc Sports Nutr 18, 27 (2021). https://doi.org/10.1186/s12970-021-00422-8
2 Wismann J, Willoughby D. Gender differences in carbohydrate metabolism and carbohydrate loading. J Int Soc Sports Nutr. 2006 Jun 5;3(1):28-34. doi: 10.1186/1550-2783-3-1-28. PMID: 18500960; PMCID: PMC2129154.
3 Cowley, E. S., Olenick, A. A., McNulty, K. L., & Ross, E. Z. (2021). “Invisible Sportswomen”: The Sex Data Gap in Sport and Exercise Science Research, Women in Sport and Physical Activity Journal, 29(2), 146-151.
4 Kerksick, C.M., Wilborn, C.D., Roberts, M.D. et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr 15, 38 (2018). https://doi.org/10.1186/s12970-018-0242-y
5 Escobar KA, VanDusseldorp TA, Kerksick CM. Carbohydrate intake and resistance-based exercise: are current recommendations reflective of actual need? Br J Nutr. 2016 Dec;116(12):2053-2065. doi: 10.1017/S0007114516003949. Epub 2016 Dec 20. PMID: 27993175.
6 Vargas-Molina S, Petro JL, Romance R, Kreider RB, Schoenfeld BJ, Bonilla DA, Benítez-Porres J. Effects of a ketogenic diet on body composition and strength in trained women. J Int Soc Sports Nutr. 2020 Apr 10;17(1):19. doi: 10.1186/s12970-020-00348-7. PMID: 32276630; PMCID: PMC7146906.
7 Valenzuela PL, Castillo-García A, Lucia A, Naclerio F. Effects of Combining a Ketogenic Diet with Resistance Training on Body Composition, Strength, and Mechanical Power in Trained Individuals: A Narrative Review. Nutrients. 2021 Sep 1;13(9):3083. doi: 10.3390/nu13093083. PMID: 34578961; PMCID: PMC8469041.
8 Henselmans M, Bjørnsen T, Hedderman R, Vårvik FT. The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review. Nutrients. 2022 Feb 18;14(4):856. doi: 10.3390/nu14040856. PMID: 35215506; PMCID: PMC8878406.