Muscle Gain & Exercise
Exercise is planned, structured, and repetitive physical activity that aims to maintain or improve physical fitness. Muscle gain is a consequence of muscle protein synthesis exceeding muscle protein breakdown and is provoked by exercise and diet.
Last Updated: August 16 2022
Muscle tissue is constantly turning over, with the rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB) fluctuating throughout the day. Net protein balance is the difference between MPS and MPB. For an increase in muscle mass to occur, MPS must exceed MPB, resulting in a positive net protein balance.[1] MPS is very sensitive to exercise and diet (namely, essential amino acid intake).
Why is exercise and muscle gain important?
What type of exercise is best for muscle gain?
What are the different bioenergetic systems that fuel muscle?
What evidence-based methods are there for decreasing soreness after exercise?
Why do my muscles get sore?
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Will lifting weights convert my fat into muscle?
An adequate energy intake is essential to optimize exercise performance and adaptations — if one maintains an energy-deficient diet during training, muscle loss, impaired recovery, illness, decreased bone mineral density, poor mood, and menstrual dysfunction can occur.[2] Consuming a hypercaloric diet augments resistance-training-induced increases in muscle mass.[3]
Beyond general energy intake, carbohydrate intake is important because it serves as a primary fuel source over a wide range of exercise intensities, and a robust body of evidence demonstrates that matching carbohydrate availability to exercise demands enhances both prolonged endurance exercise and intermittent high-intensity exercise performance.[4] Additionally, dietary protein intake is essential for the synthesis and repair of muscle tissue and is required after exercise to elicit a positive net protein balance.[5]
Supplements may benefit exercise performance and muscle gain by providing a convenient form of energy and nutrients (e.g., powdered proteins such as whey protein or vegetable protein sources, carbohydrate drinks and gels), correcting or preventing nutrient deficiencies, improving recovery from exercise, or enhancing exercise performance directly.[6] The supplements of most interest for enhancing exercise performance directly are creatine, caffeine, nitrate, citrulline, beta-alanine, and sodium bicarbonate.[6]
Should I take BCAAs before exercise if I work out while fasted?
Will supplementing with BCAAs and arginine increase exercise performance?
Creatine doesn’t seem to work for me. What should I do?
Does the menstrual cycle affect caffeine’s performance-enhancing properties?
Does creatine benefit elite athletes?
Fact check: does glutamine build muscle?
Easily compare what works and what doesn't.
While there is a general consensus that exercising in the morning or afternoon benefits sleep, it’s often recommended to avoid exercising, especially at a high intensity, in the evening in fear of it negatively affecting sleep.
However, according to a meta-analysis published in 2021, an acute bout of high-intensity exercise performed 2–4 hours before bedtime does not disrupt sleep.[123] In fact, performing high-intensity exercise 2 hours before bedtime tends to increase total sleep time (+16 minutes) and decrease the time it takes to fall asleep (−5 minutes). However, longer duration high-intensity exercise (>30–60 minutes) may decrease rapid-eye movement sleep to a small extent (−3%).
In a 7-week study in elite youth soccer players, an evening high-intensity exercise session did not affect sleep quality and slightly increased sleepiness at bedtime, compared to nights where no exercise was performed.[124]
In sum, high-intensity evening exercise does not appear to negatively affect sleep. However, careful consideration should be given to pre-workout supplements when exercising in the evening, as products containing caffeine can negatively affect sleep.
There is no convincing evidence that creatine can increase your testosterone levels.