Carbs and protein are critical for resistance training, endurance training, and recovery. This is obvious, but why and how much, respectively, is needed for optimal results? Cut the confusion with carb and protein intake with these practical findings from the latest research. We’ll dive into questions, such as:

• Protein timing and intake are essential for optimal muscle hypertrophy, but which is most important?
• Are carbs as crucial in strength training as endurance training?
• How much carbs and protein is best for recovery?

In this article, we’ll examine the research to determine the latest recommendations on carb and protein intake for performance.

Carbohydrate Timing and Intake

Carbohydrates’ importance in sports performance, especially endurance activities, is well documented. However, their role in resistance training and recovery is also essential but not as well known. The body uses carbohydrates to create glycogen, a stored form of glucose that is the body’s preferred energy source for moderate to high-intensity exercises. 

Glycogen is stored in the liver and muscles and can be stored in the body in more significant amounts in individuals with higher training status’.

Resistance training

Carbs are essential to replenish muscle glycogen after working out, but is extra carbohydrate supplementation necessary beyond a regular diet? The short answer is no. Regarding resistance training, less than 90 minutes a session once daily, carb intake from a regular diet is sufficient (unless you do something else intense within the same day).

A recent systematic review examined how carbohydrate consumption within 24 hours before a workout affected resistance training performance (Henselmens et al., 2022). Nearly two-thirds of the studies the review examined showed no difference in performance, with the other third showing that high carb intake led to greater performance. 

The review explained that the studies that did show a positive correlation with increased carbs were likely because the participants’ overall caloric intake was increased. They felt satiated, both of which can improve performance. This means it wasn’t possible due to the higher carbs but the higher caloric intake. 

The authors also explain that the typical athlete has 500 grams of stored muscle glycogen and that a typical one-hour resistance training session only uses around 80 grams of carbohydrate to fuel, or 16% muscle glycogen depletion. In sum, adequate overall caloric intake is more important than the amount of carbs for resistance training performance. 

Another author writes that resistance and power athletes do not need as many carbohydrates as endurance athletes to maintain adequate glycogen stores (Bonilla et al., 2020). In a different study, there was no difference in muscle mass and strength between high and low carbs, but high carbs may have some small advantages (Ribeiro). Remember, training status strongly influences an individual’s nutritional needs. 

It is common for novice lifters to get faint, lightheaded, or dizzy if they don’t eat much before a session. In these scenarios, it is recommended that they eat adequate carbs an hour or two before a session and have some on hand in case these symptoms arise. Personal trainers should also have some readily available carbs, such as honey or a sports drink, to offer to their clients if these symptoms occur as well. 

For optimal recovery, one study on supplementation strategies for strength athletes recommends consuming 1.2 g/kg of carbohydrates combined with 0.4 g/kg of protein within a few hours of a workout (Bird et al., 2024). This recommendation can easily be attained through a regular planned meal and is significantly lower than recommendations for endurance athletes. 

Endurance Training

While carbohydrates may not matter much in a one-hour training session, such as in a typical resistance training session, endurance training does require optimal carbohydrate intake (Kerksick et al., 2018). Endurance training includes competitions over 90 minutes, multiple events within one day, and other multi-day events.

Training status matters greatly when determining how much CHO ingestion is needed before exercise. For example, untrained people can have around 200 mmol/kg of glycogen, whereas highly trained individuals can have over 800 mmol/kg (Podloger et al., 2022). This means glycogen depletion can happen much earlier in less-trained people, so they may need to supplement with pre-carb intake more than highly trained people. Therefore, more novice individuals participating in endurance activities may want to consume extra carbs beforehand and have some on standby. 

To achieve muscle glycogen loading, athletes are recommended to consume a very high carbohydrate diet (i.e., 10–12 g·kg−1 body mass [BM] for 36–48 h before a competition (Podloger et al., 2022).

It is recommended that athletes ingest up to 60 g per hour of rapidly digestible carbohydrates, such as glucose or glucose-fructose mixes, for exercise sessions that are up to three hours long (Podloger et al., 2022). 

Recovery/Post-Competition and Training

The main factors to consider when planning carbohydrates for recovery are the time until the next training session or competition, the type of exercise, nutritional needs, and other highly individual factors (Bonilla et al., 2020).

The purpose of carbohydrates after the competition is to recover the liver and muscle glycogen stores. Replete muscle glycogen stores take 24-36 hours (Podloger et al., 2022). Current nutritional guidelines recommend athletes ingest carbohydrates as soon as possible at the rate of 1.0–1.2 g per kg to optimize repletion of glycogen stores for the first 4 hours if rapid glycogen repletion is needed for another bout of exercise. A typical diet is recommended if another training session or competition is more than two days away (Podloger et al., 2022).

Another factor to consider for recovery is the individual’s training status. If an individual is at a high training status, they will be able to store more muscle glycogen and thus may be able to replenish with a higher dose than recommended (Podloger et al., 2022).

The International Society of Sports Nutrition ranks daily carbohydrate needs as follows:

Moderate duration/low-intensity training (e.g., 2–3 h per day of intense exercise performed 5–6 times per week): 5–8 g·kg−1 body mass·day−1

Moderate to heavy endurance training (e.g., 3–6 h per day of intense training in 1–2 daily workouts for 5–6 days per week): 8–10 g·kg−1 body mass·day−1

Extreme exercise programs or competition (+6 h per day or high competition frequency during the week): 10–12 + g·kg−1 body mass·day−1

Review of Recommendations from the Podlogar et al. Review Study

Source: Podlogar T, Wallis GA. New Horizons in Carbohydrate Research and Application for Endurance Athletes. Sports Med. 2022

Resistance training would fall under the sub-ninety-minute and moderate to heavy intensity sections. As the table shows, carbohydrate planning, aside from regular dietary routines, is unnecessary. As exercise duration and intensity increase, the need for specially planned carbohydrate intake is advised. 

Protein Timing and Intake

Net protein balance regulates whether the body will promote protein synthesis or breakdown (Deldicque et al., 2022). In this next section, we’ll answer some of your biggest questions regarding protein if muscle hypertrophy is your client’s goal. These questions include protein timing, quantity, and quality. 

Protein Timing

We all want to get the most bang for our buck regarding protein intake. How often should you consume protein during workouts and throughout the day? Luckily, you don’t have to put too much pressure on yourself to time your protein intake because research shows that total daily protein intake is the most decisive factor in hypertrophy (Schoenfeld et al., 2013). These findings dispel the belief that protein timing around a training session is critical.

A meta-analysis on the role of protein timing and hypertrophy analyzed studies that utilized different protein timing, such as not around a workout and right after or before a workout (Wirth et al., 2020). Protein supplementation had a significant impact on hypertrophy independent of its timing. You should focus on increasing the overall protein intake instead of trying to time it in a particular way.

The International Society of Sports Nutrition’s 2017 position on protein also emphasizes total protein intake. However, contrary to recent recommendations, ISSN recommends protein within 2 hours of a workout and spaced daily intake every 3-4 hours with up to a 40g dose (ISSN Position Stand).

Protein Quantity

Now that we know that the anabolic window of opportunity for protein timing isn’t restricted to near the workout but rather the entire day, how much protein is needed for hypertrophy? The Recommended Dietary Allowance 10th edition suggests 0.8g/kg/day of protein intake (RDA). However, this has been known to be too little for a while now (Jager et al., 2017). The Acceptable Macronutrient Distribution Range recommends intakes of protein between 10-35% of daily caloric intake (Wolfe et al., 2017).

Active people should not be close to the RDA of 0.8g/kg/day since that was created for the minimum to prevent muscle protein breakdown and does not consider activity level. The AMDR of 10-35% caloric intake, or 1.05–3.67 g/kg/day, is more appropriate. For healthy adults who exercise, 1-1.6g/kg/day may be relevant. 

A higher protein intake may be recommended for weight loss adults in a caloric deficit. For example, in a study with participants in a 40% caloric deficit, the 2.4 g/kg/day group resulted in more muscle preservation and more fat mass loss compared to a group consuming 1.2 g/kg/day (Longland et al., 2016). Increased satiety, reduced hunger, and mitigated stress were also found in weight loss adults near 2.8 g/kg/day compared to 1.8 g/kg/day (Roberts et al., 2018, Helms).

Higher protein intake is also recommended for those looking to put on muscle. The research ranges from 1.6-2.7 g/kg/day of protein (Roberts et al., 2018). Since there is currently little evidence that high protein intake negatively impacts health in healthy populations, 1.8-2.7 g/kg/day, or up to 3.5 g/kg/day to mitigate hunger, is recommended as long as fat or carbohydrate in the diet isn’t displaced to the degree that it impairs performance.

Protein Quality

Studies comparing plant vs animal protein often measure muscle protein synthesis or strength and hypertrophy gains. Muscle protein synthesis doesn’t always mean strength and hypertrophy will increase practically (Witard et al., 2021). Therefore, it is essential to focus more on the studies that show practical chronic differences, such as increased strength and hypertrophy, rather than acute muscle protein synthesis changes. 

Omnivorous and vegan diets can support similar muscle size and strength during prolonged high-volume resistance training, irrespective of the type of dietary protein (Monteyne et al., 2023; Hevia et al., 2021). Therefore, a carefully designed vegan diet can support optimal muscle improvements to resistance training. Pea protein has the best amino acid profile for vegans.

Conclusion

In conclusion, while carbohydrates are vital for sustaining performance in endurance sports, their role in resistance training is more nuanced. For athletes in resistance training sessions lasting under 90 minutes, typical dietary carbohydrate intake is generally sufficient for maintaining muscle glycogen stores, provided overall caloric needs are met. 

However, for endurance athletes, especially those facing multi-day events or long-duration workouts, strategic carbohydrate timing and intake become essential to maximize performance and recovery. Individual factors, such as training status, also play a significant role, with well-trained athletes often able to store and utilize glycogen more effectively. 

Understanding one’s training demands and energy needs can help athletes optimize carbohydrate intake, enhancing performance and recovery for their specific athletic pursuits.

While the timing of protein intake around workouts may not be as critical as once thought, the total daily protein intake remains the most important factor for muscle hypertrophy. Research consistently supports prioritizing overall protein consumption, with recommendations varying depending on individual goals, activity levels, and dietary preferences. 

For those aiming to build muscle, a protein intake of 1.6-2.7 g/kg/day is generally ideal, with higher intakes potentially benefiting those in a caloric deficit or looking to mitigate hunger. Both plant and animal proteins can be effective for hypertrophy, with well-planned vegan diets offering comparable results to omnivorous ones. Focusing on total protein intake and quality will maximize hypertrophy and support overall muscle growth.

References

1. Bird SP, Nienhuis M, Biagioli B, De Pauw K, Meeusen R. Supplementation Strategies for Strength and Power Athletes: Carbohydrate, Protein, and Amino Acid Ingestion. Nutrients. 2024 Jun 14;16(12):1886. doi: 10.3390/nu16121886. PMID: 38931241; PMCID: PMC11206787.
2. Bonilla DA, Pérez-Idárraga A, Odriozola-Martínez A, Kreider RB. The 4R’s Framework of Nutritional Strategies for Post-Exercise Recovery: A Review with Emphasis on New Generation of Carbohydrates. Int J Environ Res Public Health. 2020 Dec 25;18(1):103. doi: 10.3390/ijerph18010103. PMID: 33375691; PMCID: PMC7796021.
3. Deldicque L. Protein Intake and Exercise-Induced Skeletal Muscle Hypertrophy: An Update. Nutrients. 2020 Jul 7;12(7):2023. doi: 10.3390/nu12072023. PMID: 32646013; PMCID: PMC7400877.
4. Helms ER, Zinn CR, Rowlands DS, Naidoo R, Cronin J. High-protein, low-fat, short-term diet results in less stress and fatigue than moderate-protein moderate-fat diet during weight loss in male weightlifters: a pilot study. Int J Sport Nutr Exerc Metab. 2015;25:163–70.
5. 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.
6. Hevia-Larraín V, Gualano B, Longobardi I, Gil S, Fernandes AL, Costa LAR, Pereira RMR, Artioli GG, Phillips SM, Roschel H. High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores. Sports Med. 2021 Jun;51(6):1317-1330. doi: 10.1007/s40279-021-01434-9. Epub 2021 Feb 18. PMID: 33599941.
7. International Society of Sports Nutrition Position Stand: protein and exercise
8. Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M, Ziegenfuss TN, Ferrando AA, Arent SM, Smith-Ryan AE, Stout JR, Arciero PJ, Ormsbee MJ, Taylor LW, Wilborn CD, Kalman DS, Kreider RB, Willoughby DS, Hoffman JR, Krzykowski JL, Antonio J. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017 Jun 20;14:20. doi: 10.1186/s12970-017-0177-8. PMID: 28642676; PMCID: PMC5477153.
9. Kerksick C.M., Wilborn C.D., Roberts M.D., Smith-Ryan A., Kleiner S.M., Jäger R., Collins R., Cooke M., Davis J.N., Galvan E., et al. ISSN exercise & sports nutrition review update: Research & recommendations. J. Int. Soc. Sports Nutr. 2018;15 doi: 10.1186/s12970-018-0242-y. 
10. Kerksick CM, Arent S, Schoenfeld BJ, Stout JR, Campbell B, Wilborn CD, Taylor L, Kalman D, Smith-Ryan AE, Kreider RB, Willoughby D, Arciero PJ, VanDusseldorp TA, Ormsbee MJ, Wildman R, Greenwood M, Ziegenfuss TN, Aragon AA, Antonio J. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 2017 Aug 29;14:33. doi: 10.1186/s12970-017-0189-4. PMID: 28919842; PMCID: PMC5596471.
11. Longland TM, Oikawa SY, Mitchell CJ, Devries MJ, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr. 2016;103:738–46. 
12. Monteyne AJ, Coelho MOC, Murton AJ, Abdelrahman DR, Blackwell JR, Koscien CP, Knapp KM, Fulford J, Finnigan TJA, Dirks ML, Stephens FB, Wall BT. Vegan and Omnivorous High Protein Diets Support Comparable Daily Myofibrillar Protein Synthesis Rates and Skeletal Muscle Hypertrophy in Young Adults. J Nutr. 2023 Jun;153(6):1680-1695. doi: 10.1016/j.tjnut.2023.02.023. Epub 2023 Feb 22. PMID: 36822394; PMCID: PMC10308267.
13. National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances. Recommended Dietary Allowances: 10th Edition. Washington (DC): National Academies Press (US); 1989. 6, Protein and Amino Acids. Available from: https://www.ncbi.nlm.nih.gov/books/NBK234922/
14. Podlogar T, Wallis GA. New Horizons in Carbohydrate Research and Application for Endurance Athletes. Sports Med. 2022 Dec;52(Suppl 1):5-23. doi: 10.1007/s40279-022-01757-1. Epub 2022 Sep 29. PMID: 36173597; PMCID: PMC9734239.
15. Roberts BM, Helms ER, Trexler ET, Fitschen PJ. Nutritional Recommendations for Physique Athletes. J Hum Kinet. 2020 Jan 31;71:79-108. doi: 10.2478/hukin-2019-0096. PMID: 32148575; PMCID: PMC7052702.
16. Roberts J, Zinchenko A, Mahbubani K, Johnstone J, Smith L, Merzbach V, Blacutt M, Banderas O, Villasenor L, Varvik FT, Henselmans M. Satiating Effect of High Protein Diets on Resistance-Trained Subjects in Energy Deficit. Nutrients. 2018. p. 11.
17. Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013 Dec 3;10(1):53. doi: 10.1186/1550-2783-10-53. PMID: 24299050; PMCID: PMC3879660.
18. Wirth J, Hillesheim E, Brennan L. The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Nutr. 2020 Jun 1;150(6):1443-1460. doi: 10.1093/jn/nxaa049. PMID: 32232404.
19. Witard OC, Bannock L, Tipton KD. Making Sense of Muscle Protein Synthesis: A Focus on Muscle Growth During Resistance Training. Int J Sport Nutr Exerc Metab. 2022 Jan 1;32(1):49-61. doi: 10.1123/ijsnem.2021-0139. Epub 2021 Oct 25. PMID: 34697259.
20. Wolfe RR, Cifelli AM, Kostas G, Kim IY. Optimizing Protein Intake in Adults: Interpretation and Application of the Recommended Dietary Allowance Compared with the Acceptable Macronutrient Distribution Range. Adv Nutr. 2017 Mar 15;8(2):266-275. doi: 10.3945/an.116.013821. PMID: 28298271; PMCID: PMC5347101.