As some us restart or ramp up physical activity and exercise, in the new year or at any time, short-term muscle aches and pains might be something to contend with. Post-workout recovery is a dynamic process that your body undergoes to repair, refuel and rebuild after exercise. Understanding the timeline can help you optimise this process, make consistent progress and avoid injury.
As ever, please talk to your doctor or medical practitioner most familiar with your medical history before implementing any changes in diet, exercise or lifestyle, especially if you are under treatment. Links to relevant studies at bottom of page.
Timeline of Recovery
Here is a breakdown of what happens to muscles, hour by hour, after a strength workout. This can apply to any part of the body. Note that we review tendon recovery separately and in more detail further below.
0–2 Hours Post-Workout: The Immediate Phase
Immediately after strength training, your muscles experience acute physiological stress. The mechanical load causes microtears in muscle fibers. These microtears trigger the release of inflammatory markers (e.g., cytokines such as interleukin-6) and stress hormones like cortisol, initiating the repair process.
To compensate for the energy expended, blood flow to muscles increases, delivering oxygen, glucose, and amino acids to support recovery. Glycogen stores, the primary fuel source for muscular work, are significantly depleted. Muscle cell membranes (sarcolemma) become more permeable, making muscle cells highly responsive to nutrient uptake.
This is an optimal window for nutrient intake, particularly carbohydrates to replenish glycogen. Hydration is also crucial for fluid balance, thermoregulation and electrolyte restoration. Learn more on hydration here.
2–6 Hours Post-Workout: The Initial Recovery Phase
During this phase, muscle protein synthesis (MPS) begins increasing, initiating the process of rebuilding and strengthening muscle fibers. The immune system continues clearing out damaged cellular components while releasing growth factors (e.g., insulin-like growth factor-1, IGF-1) that stimulate regeneration.
Meanwhile, the body prioritises glycogen replenishment, which can take up to 24 hours depending on exercise intensity and carbohydrate intake.
Adequate rest and continued hydration are essential during this stage, as they support circulatory efficiency and ensure nutrients reach recovering tissues.
6–24 Hours Post-Workout: The Growth Phase
As the body transitions to a more anabolic (muscle-building) state, muscle protein synthesis peaks, typically around 24 hours post-exercise. Muscle fibers integrate amino acids to rebuild themselves stronger, a process driven by previously consumed protein and carbohydrates.
During sleep, growth hormone (GH) levels rise, further enhancing tissue repair and adaptation.
At this point, Delayed Onset Muscle Soreness (DOMS) may begin to appear. Contrary to common belief, DOMS is not caused by lactic acid buildup, but rather by inflammatory responses and microscopic damage to the extracellular matrix surrounding muscle fibres.
Active recovery methods, such as light stretching or low-intensity activities, can improve circulation and lymphatic drainage, potentially reducing soreness and stiffness.
Cold Water Immersion (CWI) Considerations
While ice baths or cold water immersion can reduce muscle soreness, they also blunt hypertrophic signaling pathways (e.g., mTOR activation), potentially reducing muscle growth and adaptation. Their use should be tailored to individual goals. Learn more here.
24–48 Hours Post-Workout: The Consolidation Phase
By this time, the inflammatory response typically peaks and the repair process is in full swing. Glycogen stores are nearing full restoration, and structural adaptations are taking place at the cellular level.
By 36 hours post-exercise, muscle protein synthesis has returned to baseline, provided that proper nutrition and rest were maintained.
Hydration remains important as muscle cells draw in water along with glycogen, impacting muscle volume and function.
Low-impact mobility work (e.g., walking, foam rolling, or gentle yoga) can help alleviate lingering stiffness, but excessive use of NSAIDs (non-steroidal anti-inflammatory drugs) may interfere with natural adaptation and should be used judiciously.
48–72 Hours Post-Workout: Late Recovery & Neuromuscular Adaptations
At this stage, muscle repair and hypertrophy (growth) are largely complete, though neuromuscular adaptations continue. Improved motor unit recruitment and neural efficiency enhance movement coordination and strength gains.
DOMS typically subsides around this time, though it may persist longer in untrained individuals or after particularly intense workouts.
If soreness is manageable, moderate-intensity exercise can be resumed, but it's generally advisable to allow at least 48 hours of rest before reworking the same muscle group to prevent overtraining and injury risk.
Beyond 72 Hours: Full Recovery & Adaptation
For most individuals, complete muscle recovery occurs within 72 hours, though factors like training volume, fitness level, age, and recovery strategies influence this timeline. During this period, connective tissues (tendons and fascia) continue adapting, strengthening in response to increased mechanical demands. This is one reason tendons require a longer recovery period than muscle fibres.
Long-term progress depends on consistent attention to sleep, nutrition, hydration, and structured training progression.
Tendons
Tendons attach the muscles to the bones. Post-exercise tendon recovery is distinct from muscular recovery due to differences in the structure and vascularisation (blood supply) of tendons compared to muscles. Tendons are composed primarily of dense collagen fibers, which provide tensile strength but are relatively avascular, limiting their ability to quickly repair micro-trauma.
Unlike muscles, which recover relatively rapidly due to their rich blood supply and higher regenerative capacity, tendons often require a longer recovery period to fully heal and remodel. It is important to include sufficient rest into any exercise programme and too avoid increasing exercise volume too quickly to allow the body to fully recover and avoid injury.
Insufficient tendon recovery can lead to overuse injuries, such as tendinopathies, highlighting the importance of distinguishing tendon and muscle recovery protocols to optimise post-exercise adaptation and injury prevention.
If you want to stretch as part of your exercise routine, do so after your muscles have warmed up - post exercise. Interestingly, improving flexibility is associated with increased longevity.
Protein Timing
Protein timing, immediately after exercise, is not so important as it was once believed to be. By far the most important issue is to eat sufficient protein to meet one's requirements on a daily basis. Spreading protein intake over 3 or more meals, with a protein rich breakfast (after the overnight 'fast') supports recovery and growth. How much protein do we need? Learn more here.
It is also vital to consume sufficient carbohydrates to support activity levels and 'fuel the machine', even when trying to lose weight.
Final Thoughts
By following these guidelines and paying attention to your body’s signals, you can enhance your recovery process and maximise the benefits of your strength workouts. We prefer to take a cautious approach, prioritising injury avoidance over maximising gains. Proper diet, sleep and patience supports the middle age athlete!
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Related Studies and Resources
Helland C, Midttun M, Saeland F, Haugvad L, Schäfer Olstad D, Solberg PA, Paulsen G. A strength-oriented exercise session required more recovery time than a power-oriented exercise session with equal work. PeerJ. 2020 Sep 30;8:e10044. doi: 10.7717/peerj.10044. PMID: 33062443; PMCID: PMC7532781.
Charest J, Grandner MA. Sleep and Athletic Performance: Impacts on Physical Performance, Mental Performance, Injury Risk and Recovery, and Mental Health. Sleep Med Clin. 2020 Mar;15(1):41-57. doi: 10.1016/j.jsmc.2019.11.005. PMID: 32005349; PMCID: PMC9960533.
Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018 Mar;52(6):376-384. doi: 10.1136/bjsports-2017-097608. Epub 2017 Jul 11. Erratum in: Br J Sports Med. 2020 Oct;54(19):e7. doi: 10.1136/bjsports-2017-097608corr1. PMID: 28698222; PMCID: PMC5867436.
Dupuy O, Douzi W, Theurot D, Bosquet L, Dugué B. An Evidence-Based Approach for Choosing Post-exercise Recovery Techniques to Reduce Markers of Muscle Damage, Soreness, Fatigue, and Inflammation: A Systematic Review With Meta-Analysis. Front Physiol. 2018 Apr 26;9:403. doi: 10.3389/fphys.2018.00403. PMID: 29755363; PMCID: PMC5932411.
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.
Lee EC, Fragala MS, Kavouras SA, Queen RM, Pryor JL, Casa DJ. Biomarkers in Sports and Exercise: Tracking Health, Performance, and Recovery in Athletes. J Strength Cond Res. 2017 Oct;31(10):2920-2937. doi: 10.1519/JSC.0000000000002122. PMID: 28737585; PMCID: PMC5640004.
MacDougall JD, Gibala MJ, Tarnopolsky MA, MacDonald JR, Interisano SA, Yarasheski KE. The time course for elevated muscle protein synthesis following heavy resistance exercise. Can J Appl Physiol. 1995 Dec;20(4):480-6. doi: 10.1139/h95-038. PMID: 8563679.
Tendons
Brumitt J, Cuddeford T. CURRENT CONCEPTS OF MUSCLE AND TENDON ADAPTATION TO STRENGTH AND CONDITIONING. Int J Sports Phys Ther. 2015 Nov;10(6):748-59. PMID: 26618057; PMCID: PMC4637912.
Quinlan JI, Narici MV, Reeves ND, Franchi MV. Tendon Adaptations to Eccentric Exercise and the Implications for Older Adults. J Funct Morphol Kinesiol. 2019 Aug 20;4(3):60. doi: 10.3390/jfmk4030060. PMID: 33467375; PMCID: PMC7739434.
Kubo K, Ikebukuro T, Maki A, Yata H, Tsunoda N. Time course of changes in the human Achilles tendon properties and metabolism during training and detraining in vivo. Eur J Appl Physiol. 2012 Jul;112(7):2679-91. doi: 10.1007/s00421-011-2248-x. Epub 2011 Nov 22. PMID: 22105708.
Good and comprehensive article on Post Workout Care