Life Extension Magazine®

Boost Physical and Mental Energy

Clinical trials showed that creatine boosted work- out capacity, while carnitine increased energy, muscle mass, and cognitive function scores.

By Michael Downey.

Two amino acid-derived compounds support energy-generating functions in the body.

Creatine is found naturally in muscle, brain, and other cells that have high-energy demand.

It forms a compound inside cells that provides the power required to ‘recycle’ adenosine triphosphate (ATP).

ATP powers vital cellular functions.¹

Carnitine facilitates transport of fatty acids inside mitochondria to produce more ATP.^2,3

Our bodies can produce both amino acid-derived compounds, but we also rely on the diet (up to 50% of the body’s need for creatine is from diet)–mostly animal products.^2,4

Low dietary intake of amino acids and their decreased synthesis in the elderly is associated with decreased muscle mass.⁵

Creatine^6,7 and carnitine8 content in muscle is lower in vegetarians and the elderly.

And what is fascinating about this article is that it describes clinical studies showing benefits in 100-year-old humans.

Aging is associated with reduction in muscle mass, increase in intramuscular fat, frailty, and fatigue. But there’s a partial solution to this problem.

In clinical studies:

Creatine intake demonstrated ergogenic benefits,^9-11 improved muscle mass,¹² and reduced fat mass,¹³ while enhancing exercise performance^9-11,14 in various age groups and levels of training. In one clinical trial of women around 65 years old, daily creatine intake resulted in boosting training volume by 164%.¹⁴
Carnitine intake boosted mental and physical energy levels, reduced mental and physical fatigue,^15,16 enhanced cognitive and neurological function,^17-19 and improved frailty scores.^15,16

Together, these compounds may help maintain body composition and mental and physical energy levels well into older age.

Creatine Supports Physical Performance

Because creatine helps recycle the ATP pool, it is especially important during high-energy demand activities such as high-intensity training.^20-22 For this reason, creatine has long been used by athletes to boost performance and build muscle strength.²¹

Furthermore, clinical studies have shown creatine has similar benefits in older, non-athletes as well.¹⁰

A review published by the International Society of Sports Nutrition stated that creatine improves the performance of high-intensity tasks like weight training, running, and swimming by 10%-20% in athletes and active younger and older adults.¹⁰

A meta-analysis showed that in healthy older adults, creatine protected against age-related muscle loss, leading to increases in lean tissue mass and upper and lower body strength.¹¹

In one clinical study, men and women 60-80 years old took either 5,000 mg of creatine monohydrate (the most-studied form of oral creatine) or a placebo daily.

After 12 weeks that included resistance training, those taking creatine had significantly reduced fat mass and increased muscle mass compared to the placebo group.¹²

In another study, healthy women with an average age of about 65 years were given 5,000 mg of creatine monohydrate or a placebo daily. After 12 weeks that included resistance training, the creatine group had, compared to placebo:¹⁴

164% greater training volume (the amount of work done in a workout in a given time),
5.1% increased bench press capacity,
8.8% improved biceps curl performance, and
Almost 4% greater knee extension performance.

A similar trial involved men and women with an average age of about 70 years, who took either 5,000 mg of creatine monohydrate or a placebo daily for 14 weeks.¹³

Compared to individuals who received the placebo, those in the creatine group had:¹³

Increased lean tissue mass, and
Greater isometric knee extension strength.

Mental, Physical, and Cognitive Effects of Carnitine

Carnitine supports whole-body energy and cognitive function. One clinical study looked at subjects 100 years of age or older who felt fatigue after even slight physical activity. Those who took 2,000 mg of L-carnitine daily for six months had, compared to a placebo:²³

Reduced physical fatigue,
Decreased mental fatigue,
Lower fatigue severity,
Decreased total fat mass, and
Greater total muscle mass.

In another clinical trial, older adults considered prefrail (at high risk of frailty) were given either a placebo or 1,500 mg of L-carnitine daily for 10 weeks.¹⁶

Among the treatment group, 42.3% felt more energetic, compared to 16.7% of the placebo group. The carnitine group also had improved mean scores on the Frailty Index and improved hand grip test scores.¹⁶

What You Need To Know

Fight Fatigue with Creatine and Carnitine

Adenosine triphosphate (ATP) is the source of energy for use and storage at the cellular level.
Creatine and carnitine have ergogenic benefits by supporting ATP recycling and ATP synthesis, respectively.
Lower levels of creatine and carnitine are associated with aging, frailty and reduced energy.
In clinical trials, creatine improved muscle mass, reduced fat mass, and enhanced several aspects of exercise performance.
In other clinical studies, carnitine boosted energy, reduced mental and physical fatigue, and improved cognitive function and body composition.

Improvement in cognitive function with carnitine was also shown in healthy centenarians, as demonstrated by a significant increase in Mini-Mental State Exam scores compared with placebo,23 as well as in patients with mild cognitive impairment or Alzheimer’s Disease:

In adults 65 and older with mild mental impairment, taking 2,000 mg daily of acetyl-L-carnitine (ALC), a form of carnitine that crosses the blood-brain barrier, for three months improved cognitive function, including measures of memory and attention.²⁴
A review of clinical studies showed that the same dose, taken for one year, may delay the cognitive decline of patients with Alzheimer’s disease.²⁵

How Acetyl-L-Carnitine and Creatine Work

ATP (adenosine triphosphate) is the main carrier of energy in the body. The majority of ATP synthesis occurs within mitochondria.26

Acetyl-L-Carnitine facilitates transport of long-chain fatty acids into the mitochondria, where they are broken downto help generate ATP.²

Creatine helps form a high-energy compound in cells that provides energy used to resynthesize ATP.¹

When energy demands are high (when muscles need a rush of energy or during times of fatigue, for example), it’s faster to resynthesize degraded ATP than to synthesize new ATP.^27,28

A combination of carnitine and creatine may help improve physical and mental performance and promote healthy aging by improving energy levels, body composition, and cognitive function.

Summary

In clinical trials, creatine intake increased muscle mass, reduced fat, boosted training volume, and enhanced exercise performance.

L-Carnitine boosted energy levels and reduced mental and physical fatigue, improved frailty scores, and enhanced cognitive function.

Taken together, creatine and carnitine may help maintain cellular energy levels and reduce fatigue.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

References

Bonilla DA, Kreider RB, Stout JR, et al. Metabolic Basis of Creatine in Health and Disease: A Bioinformatics-Assisted Review. Nutrients. 2021 Apr 9;13(4).
Available at: https://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/. Accessed November 7, 2024.
Virmani MA, Cirulli M. The Role of l-Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation. Int J Mol Sci. 2022 Feb 28;23(5):2717.
Brosnan ME, Brosnan JT. The role of dietary creatine. Amino Acids. 2016 Aug;48(8):1785-91.
Landi F, Calvani R, Tosato M, et al. Protein Intake and Muscle Health in Old Age: From Biological Plausibility to Clinical Evidence. Nutrients. 2016 May 14;8(5).
Smith RN, Agharkar AS, Gonzales EB. A review of creatine supplementation in age-related diseases: more than a supplement for athletes. F1000Res. 2014;3:222.
Bartholomae E, Knurick J, Johnston CS. Serum creatinine as an indicator of lean body mass in vegetarians and omnivores. Front Nutr. 2022;9:996541.
Available at: https://lpi.oregonstate.edu/mic/dietary-factors/L-carnitine. Accessed November 7, 2024.
Mills S, Candow DG, Forbes SC, et al. Effects of Creatine Supplementation during Resistance Training Sessions in Physically Active Young Adults. Nutrients. 2020 Jun 24;12(6).
Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017 2017/06/13;14(1):18.
Chilibeck PD, Kaviani M, Candow DG, et al. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med. 2017;8:213-26.
Pinto CL, Botelho PB, Carneiro JA, et al. Impact of creatine supplementation in combination with resistance training on lean mass in the elderly. J Cachexia Sarcopenia Muscle. 2016 Sep;7(4):413-21.
Brose A, Parise G, Tarnopolsky MA. Creatine supplementation enhances isometric strength and body composition improvements following strength exercise training in older adults. J Gerontol A Biol Sci Med Sci. 2003 Jan;58(1):11-9.
Aguiar AF, Januario RS, Junior RP, et al. Long-term creatine supplementation improves muscular performance during resistance training in older women. Eur J Appl Physiol. 2013 Apr;113(4):987-96.
Malaguarnera M, Catania VE, Malaguarnera M. Carnitine derivatives beyond fatigue: an update. Curr Opin Gastroenterol. 2023 Mar 1;39(2):125-8.
Badrasawi M, Shahar S, Zahara AM, et al. Efficacy of L-carnitine supplementation on frailty status and its biomarkers, nutritional status, and physical and cognitive function among prefrail older adults: a double-blind, randomized, placebo-controlled clinical trial. Clin Interv Aging. 2016;11:1675-86.
De Grandis D, Minardi C. Acetyl-L-carnitine (levacecarnine) in the treatment of diabetic neuropathy. A long-term, randomised, double-blind, placebo-controlled study. Drugs R D. 2002;3(4):223-31.
Pennisi M, Lanza G, Cantone M, et al. Acetyl-L-Carnitine in Dementia and Other Cognitive Disorders: A Critical Update. Nutrients. 2020 May 12;12(5).
Mazdeh M, Abolfathi P, Sabetghadam M, et al. Clinical Evidence of Acetyl-L-Carnitine Efficacy in the Treatment of Acute Ischemic Stroke: A Pilot Clinical Trial. Oxid Med Cell Longev. 2022;2022:2493053.
Cooper R, Naclerio F, Allgrove J, et al. Creatine supplementation with specific view to exercise/sports performance: an update. J Int Soc Sports Nutr. 2012 Jul 20;9(1):33.
Wax B, Kerksick CM, Jagim AR, et al. Creatine for Exercise and Sports Performance, with Recovery Considerations for Healthy Populations. Nutrients. 2021 Jun 2;13(6).
Wang CC, Yang MT, Lu KH, et al. The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time. Nutrients. 2016 Mar 4;8(3):143.
Malaguarnera M, Cammalleri L, Gargante MP, et al. l-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial. The American Journal of Clinical Nutrition. 2007 2007/12/01/;86(6):1738-44.
Passeri M, Iannuccelli M, Ciotti G, et al. Mental impairment in aging: selection of patients, methods of evaluation and therapeutic possibilities of acetyl-L-carnitine. Int J Clin Pharmacol Res. 1988;8(5):367-76.
Calvani M, Carta A, Caruso G, et al. Action of acetyl-L-carnitine in neurodegeneration and Alzheimer’s disease. Ann N Y Acad Sci. 1992 Nov 21;663:483-6.
Osellame LD, Blacker TS, Duchen MR. Cellular and molecular mechanisms of mitochondrial function. Best Pract Res Clin Endocrinol Metab. 2012 Dec;26(6):711-23.
Wallimann T, Tokarska-Schlattner M, Schlattner U. The creatine kinase system and pleiotropic effects of creatine. Amino Acids. 2011 May;40(5):1271-96.
Sahlin K. Muscle energetics during explosive activities and potential effects of nutrition and training. Sports Med. 2014 Nov;44 Suppl 2(Suppl 2):S167-73.