What is muscle strength?
Muscle strength refers to the ability to produce force against an external resistance.[1] It is often divided into specific types of strength, such as lower body strength or upper body strength.
How is muscle strength measured?
Strength is commonly assessed using dynamic resistance exercise,[2] which includes concentric (muscle shortening) and eccentric (muscle lengthening) muscle actions. The most popular method is a 1-repetition maximum (1RM) test,[3] which involves lifting as much weight as possible for one repetition using either free weights or an exercise machine. A higher-repetition maximum test (i.e., a 2–6 RM) may also be used to assess strength and estimate 1RM strength.[2]
Another option is an isometric strength test, which involves producing a maximal force against an immovable resistance.[4] Unlike dynamic resistance exercise, the muscle length does not change during an isometric muscle action. Strong correlations have been reported between maximum dynamic and isometric strength.[3]
What type of exercise is best for producing muscle strength?
In accordance with the principle of specificity — which states that training adaptations are specific to the demands imposed on the body — heavy loads (≥ 80% of 1RM) are superior to lighter loads for increasing 1RM strength.[5][6] Training to muscular failure (i.e., the point at which another concentric repetition cannot be completed with proper form) is not necessary to increase muscle strength.[7] In fact, ending each set a few reps shy of failure appears to be superior to training to failure for maximizing gains in 1RM strength.[8][9] Also, rest intervals between sets should be at least 3 minutes.[10][11]
Have any supplements been studied for muscle strength?
Supplements marketed to enhance muscle strength typically claim to do so through one of the following mechanisms or a combination of them: increasing muscle contractile efficiency (e.g., by improving calcium handling in the sarcoplasmic reticulum), delaying muscular fatigue, increasing the availability of fuel sources (e.g., carbohydrate), and/or stimulating muscle protein synthesis.[22]
The most effective supplements for increasing muscle strength appear to be creatine,[23] protein,[24] and caffeine.[25] Other supplements that have been studied for muscle strength include nitrate, citrulline malate, HMB, alpha-GPC, taurine, ashwagandha, and omega-3 fatty acids.
How can diet affect muscle strength?
Nutrition plays an important role in increasing muscle strength through fueling exercise and promoting recovery and exercise-induced adaptations. These processes are mainly influenced by protein and carbohydrate intake. Evidence suggests that a total daily protein intake of about 1.6 grams per kilogram of body weight is ideal for supporting increases in strength.[26][24]
Muscle glycogen is a primary fuel source during resistance exercise,[27] and glycogen depletion is associated with muscle fatigue and impaired muscle contraction efficiency,[28] so consuming at least 3–5 grams of carbohydrate per kilogram of body weight per day is recommended to maximize strength gains.[26]
With that said, many studies have not found differences in strength gains between higher- and lower-carbohydrate diets,[29] particularly when the resistance exercise routine includes low volumes (< 10 sets per workout), high loads (≥ 80% of 1-repetition maximum), and long rest periods (≥ 3 minutes of rest between sets). However, there is a lack of evidence demonstrating benefits of lower-carbohydrate diets for muscle strength.
Which other factors affect muscle strength?
Differences in muscle strength between individuals seem to be mostly explained by differences in muscle mass,[37][38][39][40][41] which is supported by the mechanistic rationale that a larger muscle has greater force-generating capacity.[42] Other contributors to muscle strength include neural factors,[1] such as the threshold at which motor units are recruited and the motor unit discharge rate, and genetics.[43] Additionally, simply practicing the test used to examine strength (e.g., a back squat 1-repetition maximum) can promote increases in strength.[44][45]
Examine Database: Strength
Frequently asked questions
Muscle strength refers to the ability to produce force against an external resistance.[1] It is often divided into specific types of strength, such as lower body strength or upper body strength.
Strength is commonly assessed using dynamic resistance exercise,[2] which includes concentric (muscle shortening) and eccentric (muscle lengthening) muscle actions. The most popular method is a 1-repetition maximum (1RM) test,[3] which involves lifting as much weight as possible for one repetition using either free weights or an exercise machine. A higher-repetition maximum test (i.e., a 2–6 RM) may also be used to assess strength and estimate 1RM strength.[2]
Another option is an isometric strength test, which involves producing a maximal force against an immovable resistance.[4] Unlike dynamic resistance exercise, the muscle length does not change during an isometric muscle action. Strong correlations have been reported between maximum dynamic and isometric strength.[3]
In accordance with the principle of specificity — which states that training adaptations are specific to the demands imposed on the body — heavy loads (≥ 80% of 1RM) are superior to lighter loads for increasing 1RM strength.[5][6] Training to muscular failure (i.e., the point at which another concentric repetition cannot be completed with proper form) is not necessary to increase muscle strength.[7] In fact, ending each set a few reps shy of failure appears to be superior to training to failure for maximizing gains in 1RM strength.[8][9] Also, rest intervals between sets should be at least 3 minutes.[10][11]
Supplements marketed to enhance muscle strength typically claim to do so through one of the following mechanisms or a combination of them: increasing muscle contractile efficiency (e.g., by improving calcium handling in the sarcoplasmic reticulum), delaying muscular fatigue, increasing the availability of fuel sources (e.g., carbohydrate), and/or stimulating muscle protein synthesis.[22]
The most effective supplements for increasing muscle strength appear to be creatine,[23] protein,[24] and caffeine.[25] Other supplements that have been studied for muscle strength include nitrate, citrulline malate, HMB, alpha-GPC, taurine, ashwagandha, and omega-3 fatty acids.
Nutrition plays an important role in increasing muscle strength through fueling exercise and promoting recovery and exercise-induced adaptations. These processes are mainly influenced by protein and carbohydrate intake. Evidence suggests that a total daily protein intake of about 1.6 grams per kilogram of body weight is ideal for supporting increases in strength.[26][24]
Muscle glycogen is a primary fuel source during resistance exercise,[27] and glycogen depletion is associated with muscle fatigue and impaired muscle contraction efficiency,[28] so consuming at least 3–5 grams of carbohydrate per kilogram of body weight per day is recommended to maximize strength gains.[26]
With that said, many studies have not found differences in strength gains between higher- and lower-carbohydrate diets,[29] particularly when the resistance exercise routine includes low volumes (< 10 sets per workout), high loads (≥ 80% of 1-repetition maximum), and long rest periods (≥ 3 minutes of rest between sets). However, there is a lack of evidence demonstrating benefits of lower-carbohydrate diets for muscle strength.
Differences in muscle strength between individuals seem to be mostly explained by differences in muscle mass,[37][38][39][40][41] which is supported by the mechanistic rationale that a larger muscle has greater force-generating capacity.[42] Other contributors to muscle strength include neural factors,[1] such as the threshold at which motor units are recruited and the motor unit discharge rate, and genetics.[43] Additionally, simply practicing the test used to examine strength (e.g., a back squat 1-repetition maximum) can promote increases in strength.[44][45]
References
Examine Database References
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- L-Carnitine - A C Gimenes, D M Bravo, L M Nápolis, M T Mello, A S B Oliveira, J A Neder, L E NeryEffect of L-carnitine on exercise performance in patients with mitochondrial myopathyBraz J Med Biol Res.(2015 Apr)
- Boron - Green NR, Ferrando AAPlasma boron and the effects of boron supplementation in malesEnviron Health Perspect.(1994 Nov)
- Vitamin D - Soma Saha, Ravinder Goswami, Lakshmy Ramakrishnan, Sreenivas Vishnubhatla, Samrina Mahtab, Parmita Kar, Sunita Srinivasan, Namrata Singh, Upinderpal SinghVitamin D and calcium supplementation, skeletal muscle strength and serum testosterone in young healthy adult males: Randomized control trialClin Endocrinol (Oxf).(2018 Feb)
- Panax Ginseng (Korean Ginseng) - Angelheart J.M. RattuThe effect of ginseng supplementation on strength development in response to resistance exercise trainingMedical Journal of Indonesia.()
- Vitamin D - Michelle S Rockwell, Madlyn I Frisard, Janet W Rankin, Jennifer S Zabinsky, Ryan P Mcmillan, Wen You, Kevin P Davy, Matthew W HulverEffects of Seasonal Vitamin D3 Supplementation on Strength, Power, and Body Composition in College SwimmersInt J Sport Nutr Exerc Metab.(2020 Feb 4)
- OMAD And 20:4 Intermittent Fasting - Grant M Tinsley, Jeffrey S Forsse, Natalie K Butler, Antonio Paoli, Annie A Bane, Paul M La Bounty, Grant B Morgan, Peter W GrandjeanTime-restricted feeding in young men performing resistance training: A randomized controlled trialEur J Sport Sci.(2017 Mar)
- L-Tyrosine - Catherine O'Brien, Caroline Mahoney, William J Tharion, Ingrid V Sils, John W CastellaniDietary tyrosine benefits cognitive and psychomotor performance during body coolingPhysiol Behav.(2007 Feb 28)
- L-Carnitine - Angelika K Sawicka, Dace Hartmane, Patrycja Lipinska, Ewa Wojtowicz, Wieslawa Lysiak-Szydlowska, Robert A Olekl-Carnitine Supplementation in Older Women. A Pilot Study on Aging Skeletal Muscle Mass and FunctionNutrients.(2018 Feb 23)
- Citrulline - Glenn JM, Gray M, Jensen A, Stone MS, Vincenzo JLAcute citrulline-malate supplementation improves maximal strength and anaerobic power in female, masters athletes tennis playersEur J Sport Sci.(2016 Nov)
- Magnesium - L R Brilla, T F HaleyEffect of magnesium supplementation on strength training in humansJ Am Coll Nutr.(1992 Jun)
- 16:8 Intermittent Fasting - Tatiana Moro, Grant Tinsley, Antonino Bianco, Giuseppe Marcolin, Quirico Francesco Pacelli, Giuseppe Battaglia, Antonio Palma, Paulo Gentil, Marco Neri, Antonio PaoliEffects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained malesJ Transl Med.(2016 Oct 13)
- L-Carnitine - G A Barker, S Green, C D Askew, A A Green, P J WalkerEffect of propionyl-L-carnitine on exercise performance in peripheral arterial diseaseMed Sci Sports Exerc.(2001 Sep)
- 16:8 Intermittent Fasting - Grant M Tinsley, M Lane Moore, Austin J Graybeal, Antonio Paoli, Youngdeok Kim, Joaquin U Gonzales, John R Harry, Trisha A VanDusseldorp, Devin N Kennedy, Megan R CruzTime-restricted feeding plus resistance training in active females: a randomized trialAm J Clin Nutr.(2019 Sep 1)
- L-Tyrosine - Erin E Sutton, M Regina Coill, Patricia A DeusterIngestion of tyrosine: effects on endurance, muscle strength, and anaerobic performanceInt J Sport Nutr Exerc Metab.(2005 Apr)
- Soy Protein - Mark Messina, Heidi Lynch, Jared M Dickinson, Katharine E ReedNo Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance ExerciseInt J Sport Nutr Exerc Metab.(2018 Nov 1)
- Tongkat Ali - Sasikala M Chinnappan, Annie George, Pragya Pandey, Govinda Narke, Yogendra Kumar ChoudharyEffect of Eurycoma longifolia standardised aqueous root extract-Physta ® on testosterone levels and quality of life in ageing male subjects: a randomised, double-blind, placebo-controlled multicentre studyFood Nutr Res.(2021 May 19)
- Tongkat Ali - Alice Erwig Leitão, Melissa de Carvalho Souza Vieira, Diogo Almeida Gomes, Leonessa Boing, Andreia Pelegrini, Edson Luiz, Adriana Coutinho de Azevedo GuimarãesExercise associated or not to the intake of Eurycoma longifolia improves strength and cardiorespiratory fitness in men with androgen deficiencyComplement Ther Clin Pract.(2021 Feb)
- Tongkat Ali - Chen CK, Ooi FK, Abu Kasim NA, Asari MAEffects of Jack Supplementation Combined with Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic Power, and Urinary Testosterone: Epitestosterone Ratio in Young Males.Int J Prev Med.(2019)
- Tongkat Ali - Henkel RR, Wang R, Bassett SH, Chen T, Liu N, Zhu Y, Tambi MITongkat Ali as a potential herbal supplement for physically active male and female seniors--a pilot study.Phytother Res.(2014-Apr)