ArticlePDF Available

Abstract and Figures

Resistance training is a potent stimulus to enhance skeletal muscle hypertrophy and strength. Combining creatine supplementation with resistance training may be an effective strategy to enhance the physiological adaptations from resistance training alone. Emerging evidence suggests that the timing of creatine supplementation may be an important regulator of muscle hypertrophy and strength. Creatine ingested before and after resistance training sessions appear to be an effective strategy to increase muscle mass and strength, with slightly greater benefits if creatine is consumed after exercise compared to before. This brief review will evaluate the literature pertaining to the strategic ingestion of creatine and resistance training resulting in practical creatine supplementation strategies.
No caption available
Content may be subject to copyright.
Agro FOOD Industry Hi Tech - vol 25(4) - July/August 2014
KEYWORDS: supplements, creatine, strength, muscle mass, timing
AbstractResistance training is a potent stimulus to enhance skeletal muscle hypertrophy and strength. Combining
creatine supplementation with resistance training may be an effective strategy to enhance the
physiological adaptations from resistance training alone. Emerging evidence suggests that the timing of creatine supplementation
may be an important regulator of muscle hypertrophy and strength. Creatine ingested before and after resistance training sessions
appear to be an effective strategy to increase muscle mass and strength, with slightly greater benefits if creatine is consumed after
exercise compared to before. This brief review will evaluate the literature pertaining to the strategic ingestion of creatine and
resistance training resulting in practical creatine supplementation strategies.
Creatine timing on muscle mass
and strength: Appetizer or Dessert?
It is well established that the mechanical stimuli from
resistance training increases muscle protein synthesis (1).
Although the machinery for stimulating muscle protein
synthesis is increased after resistance training (2), the
anabolic response may be delayed post-exercise (3). The
combination of creatine supplementation and resistance
training may lead to greater muscle benefits than resistance
training alone in young and older adults (4, 5). Furthermore,
the timing of creatine ingestion may be an important factor
for creating an anabolic environment for muscle growth (5).
Emerging evidence suggests that creatine supplementation,
in close proximity to resistance training sessions, may provide
superior benefits compared to creatine intake at other times
of the day (6, 7). While the mechanistic actions explaining
the greater benefits from timed creatine ingestion are
unknown, it is possible that blood flow kinetics and creatine
transport are involved (8, 9). Therefore, the purpose of this
review is to 1) briefly outline the potential beneficial effects
of creatine supplementation, 2) review the emerging
evidence involving the timing of creatine supplementation
combined with resistance training, and 3) outline creatine
supplementation strategies.
Creatine, methyl-guanidino acetic acid, is a naturally
occurring nitrogen-containing compound (5, 10, 11).
Creatine excretion occurs at a rate of ~2 g∙d-1 (12).
Creatine can be replaced via endogenous synthesis (1-2
g·d-1) in the kidneys, liver, and pancreas or through dietary
intake, typically ~1-3 g·d-1 (11, 12). Creatine is found in high
concentrations in red meat and seafood (12). Ninety-five
percent of creatine is stored in skeletal muscle, of which
60-70 percent is phosphorylated (i.e. phosphocreatine)
(13). Phosphocreatine rapidly resynthesizes adenosine
diphopshate to help maintain adenosine triphosphate
(ATP) during high intensity exercise such as resistance
training (13). Theoretically, elevated phosphocreatine
stores (via creatine supplementation) may increase
exercise training intensity and the volume of work
performed leading to greater muscle accretion and
strength (reviewed in Branch (14); Rawson & Volek (15)).
Several purported mechanisms exists which may help
explain the typical increase in muscle mass and strength
from creatine (4, 5, 10). Creatine supplementation elevates
skeletal phosphocreatine and total creatine stores (16)
which increases phosphocreatine resynthesis (17) and
exercise fatigue resistance (18). Creatine may also
influence myocellular water retention due to increased
intracellular osmolarity and increase muscle glycogen
storage (19). Subsequent muscle cell swelling may
stimulate genes regulating various anabolic pathways (20).
Furthermore, creatine has been shown to increase satellite
cell differentiation (21), activity (22), and content (23);
transcription factor activity (24), hormonal secretion (e.g.
IGF-1;(25)), muscle protein kinetics (26), and decrease
inflammation (27).
*Corresponding author
1. University of Calgary, Faculty of Medicine, Department of Physiology and Pharmacology,
Alberta, T2N 4N1, Canada
2. University of Regina, Faculty of Kinesiology & Health Studies, Regina, S4S 0A2, Saskatchewan, Canada
Darren G. Candow
Agro FOOD Industry Hi Tech - vol 25(4) - July/August 2014
morning and evening
on training days, Cribb
et al. (6) showed that
creatine ingestion
before and after
exercise resulted in
significantly greater
intramuscular creatine
content, lean tissue
mass, and muscle cross
sectional-area of type II
Although it is difficult to
compare results across
studies, it has been
theorized that these
positive results from
creatine ingestion
before and after
exercise may be due to
an increase in blood
flow and delivery of
creatine to exercising
muscles (8), an
upregulation of the
kinetics involved in
creatine transport (9),
and by an increase in Na+-K+ pump function during exercise (9).
Based on the limited studies performed thus far, it appears that
creatine supplementation before and after resistance training
sessions is important for muscle and strength. Post-exercise
creatine ingestion may provide slightly greater benefits than pre-
exercise creatine supplementation.
Resistance training is an effective strategy to increase muscle
mass and strength. Emerging evidence indicates that the timing
of creatine supplementation is an important intervention for
augmenting the physiological adaptations from resistance
training alone. Creatine ingested before and after resistance
training sessions appears to be an effective strategy to increase
muscle mass and strength, with slightly greater benefits if
creatine is consumed post-exercise compared to pre-exercise.
1. Phillips, S.M., “Protein requirements and supplementation in strength
sports”, Nutr, 20(7-8), 689-95 (2004).
2. Welle, S., Thornton, C.A. “High-protein meals do not enhance
myofibrillar synthesis after resistance exercise in 62- to 75-yr-old men
and women”, Am J Physiol, 274(4 Pt 1), E677-83 (1998).
3. Tipton, K.D., Rasmussen, B.B., Miller, S.L., et al. “Timing of amino acid-
carbohydrate ingestion alters anabolic response of muscle to
resistance exercise”, American journal of physiology Endocrinology
and metabolism, 281(2), E197-206 (2001).
4. Candow, D.G., Chilibeck, P.D., Forbes, S.C. “Creatine
supplementation and aging musculoskeletal health”, Endocrine,
45(3), 354-61 (2014).
5. Forbes, S.C., Little, J.P., Candow, D.G. “Exercise and nutritional
interventions for improving aging muscle health”, Endocrine, 42(1),
29-38 (2012).
6. Cribb, P.J., Hayes, A. “Effects of supplement timing and resistance
The timing of creatine supplementation is proving to be an
important regulator of muscle growth (Table 1). The strategic
ingestion of creatine immediately before and after resistance
training sessions appears more important than ingesting creatine
at other times of the day. For example, in the most recent study,
we showed that creatine (0.1 g∙kg-1) immediately before and
immediately after resistance training sessions for 8 months
produced similar gains in muscle mass and strength. However,
compared to placebo, only post-exercise creatine resulted in
greater improvements in whole body lean tissue mass (creatine
after = 6.2 percent vs. placebo = 1.4 percent) and leg press
strength (creatine after = 28.3 percent vs. 3.4 percent;
unpublished findings). The slightly greater benefit from post-
exercise creatine supplementation indirectly supports the
findings of Antonio and Ciccone (28) who found a greater
muscle benefit from post-exercise creatine supplementation (5
g) in young adults compared to pre-exercise creatine
supplementation. We previously found no differences between
creatine supplementation (0.1 g∙kg-1) immediately before vs.
after resistance training sessions for 12 weeks in older adults (29).
However, a major limitation of the studies by Antonio and
Ciccone (28) and Candow et al. (29) was that a placebo
(control) was not used for comparison to creatine. Consuming
creatine immediately before (0.05 g∙kg-1) and immediately after
(0.05 g∙kg-1) resistance training sessions (3 days/week, 10 weeks)
resulted in greater muscle accretion (2.0 ± 0.3 cm) compared to
placebo (0.8 ± 0.3 cm) and resistance training in healthy older
males (59-77 years) (30). These results support previous findings of
a significant increase in lean tissue mass (6 percent), type II
muscle fibre area (29 percent), and insulin growth-factor I (78
percent) in adults (19-55 years) who ingested creatine before
(0.03 g∙kg-1) and after (0.03 g∙kg-1) resistance training (6 days/
week, 8 weeks) (25, 31). Interestingly, in comparing the effects of
creatine ingestion before (0.5 g∙kg-1) and after (0.5 g∙kg-1)
resistance training (10 weeks) to creatine ingestion in the
Table 1. Studies Investigation the effects of creatine timing combined with resistance training.
in human skeletal muscle”, Clin Sci (Lond), 106(1), 99-106 (2004).
20. Deldicque, L., Atherton, P., Patel, R., et al. “Effects of resistance
exercise with and without creatine supplementation on gene
expression and cell signaling in human skeletal muscle”, JAP, 104(2),
371-8 (2008).
21. Vierck, J.L., Icenoggle, D.L., Bucci, L., et al. “The effects of ergogenic
compounds on myogenic satellite cells”, MMSE, 35(5), 769-76 (2003).
22. Dangott, B., Schultz, E., Mozdziak, P.E. “Dietary creatine
monohydrate supplementation increases satellite cell mitotic activity
during compensatory hypertrophy”, IJSM, 21(1), 13-6 (2000).
23. Olsen, S., Aagaard, P., Kadi, F., et al. “Creatine supplementation
augments the increase in satellite cell and myonuclei number in
human skeletal muscle induced by strength training”, J Physiol,
573(Pt 2), 525-34 (2006).
24. Willoughby, D.S., Rosene, J.M. “Effects of oral creatine and resistance
training on myogenic regulatory factor expression”, MMSE, 35(6),
923-9 (2003).
25. Burke, D.G., Candow, D.G., Chilibeck, P.D., et al. “Effect of creatine
supplementation and resistance-exercise training on muscle insulin-
like growth factor in young adults”, IJSNEM, 18(4), 389-98 (2008).
26. Parise, G., Mihic, S., MacLennan, D., et al. “Effects of acute creatine
monohydrate supplementation on leucine kinetics and mixed-
muscle protein synthesis”, JAP, 91(3), 1041-7 (2001).
27. Bassit, R.A., Curi, R., Costa Rosa, L.F. “Creatine supplementation
reduces plasma levels of pro-inflammatory cytokines and PGE2 after
a half-ironman competition”, AA, 35(2), 425-31 (2008).
28. Antonio, J., Ciccone, V. “The effects of pre versus post workout
supplementation of creatine monohydrate on body composition
and strength”, JISSN, 10(1), 36 (2013).
29. Candow, D.G., Zello, G.A., Ling, B., et al. “Comparison of creatine
supplementation before versus after supervised resistance training in
healthy older adults”, Res Sports Med, 22(1), 61-74 (2014).
30. Candow, D.G., Little, J.P., Chilibeck, P.D., et al. “Low-dose creatine
combined with protein during resistance training in older men”,
MMSE, 40(9), 1645-52 (2008).
31. Burke, D.G., Chilibeck, P.D., Parise, G., et al. “Effect of creatine and
weight training on muscle creatine and performance in
vegetarians”, MMSE, 35(11), 1946-55 (2003).
exercise on skeletal muscle hypertrophy”, MMSE, 38(11), 1918-25
7. Candow, D.G., Chilibeck, P.D. “Timing of creatine or protein
supplementation and resistance training in the elderly”, APNM, 33(1),
184-90 (2008).
8. Harris, R.C., Soderlund, K., Hultman, E. “Elevation of creatine in resting
and exercised muscle of normal subjects by creatine
supplementation”, Clin Sci (Lond). 83(3), 367-74 (1992).
9. Robinson, T.M., Sewell, D.A., Hultman, E., et al. “Role of submaximal
exercise in promoting creatine and glycogen accumulation in
human skeletal muscle”, JAP, 87(2), 598-604 (1999).
10. Candow, D.G. “Sarcopenia: current theories and the potential
beneficial effect of creatine application strategies”, Biogerontology,
12(4), 273-81 (2011).
11. Greenhaff, P.L. “Creatine and its application as an ergogenic aid”,
IJSN, 5 Suppl, S100-10 (1995).
12. Wyss, M., Kaddurah-Daouk, R. “Creatine and creatinine
metabolism”, Physiol Rev, 80(3), 1107-213 (2000).
13. Casey, A., Greenhaff, P.L. “Does dietary creatine supplementation
play a role in skeletal muscle metabolism and performance?”, Am J
Clin Nutr, 72(2 Suppl), 607S-17S (2000).
14. Branch, J.D. “Effect of creatine supplementation on body
composition and performance: a meta-analysis”, IJSNEM, 13(2),
198-226 (2003).
15. Rawson, E.S., Volek, J.S. “Effects of creatine supplementation and
resistance training on muscle strength and weightlifting
performance”, JSCR, 17(4), 822-31 (2003).
16. Syrotuik, D.G., Bell, G.J. “Acute creatine monohydrate
supplementation: a descriptive physiological profile of responders vs.
nonresponders”, JSCR, 18(3), 610-7 (2004).
17. Greenhaff, P.L., Bodin, K., Soderlund, K., et al. “Effect of oral creatine
supplementation on skeletal muscle phosphocreatine resynthesis”,
The American journal of physiology, 266(5 Pt 1), E725-30 (1994).
18. Sahlin, K., Tonkonogi, M., Soderlund, K. “Energy supply and muscle
fatigue in humans”, Acta physiologica Scandinavica, 162(3), 261-6
19. van Loon, L.J., Murphy, R., Oosterlaar, A.M., et al. “Creatine
supplementation increases glycogen storage but not GLUT-4 expression
... To date, there have been two studies investigating the performance effects of creatine combined with high intensity interval training with preliminary positive results [40,41]. There is emerging evidence that the timing of creatine supplementation may be an important consideration [42]. Creatine ingested in close temporal proximity to training appears to be an effective strategy to increase the anabolic response [43], with slightly enhanced benefits when creatine is consumed after exercise [42,44]. ...
... There is emerging evidence that the timing of creatine supplementation may be an important consideration [42]. Creatine ingested in close temporal proximity to training appears to be an effective strategy to increase the anabolic response [43], with slightly enhanced benefits when creatine is consumed after exercise [42,44]. ...
Full-text available
Canoe polo is an emerging and growing sport. Canoe polo athletes are characterized by low body-fat percentages with high levels of upper body aerobic and anaerobic power. Canoe polo is a high intensity intermittent team sport consisting of two 10 min halves. Average heart rates during game play ranged from 146 to 159 bpm. Sixty-nine per cent of a canoe polo game is played above ventilator threshold. Due to the intensity and intermittent nature, ATP rephosphorylation occurs via non-oxidative and oxidative energy systems. A high carbohydrate diet (>6 g•kg-1•day-1) is recommended to support non-oxidative ATP re-phosphorylation during training and competitions. Following training, a rapidly digested and complete protein (e.g., whey protein; 20-40 g) provided in close proximity may maximize the muscle protein synthetic response. β-Alanine, sodium bicarbonate, creatine, caffeine, and nitrates are purported ergogenic aids to improve high intensity exercise performance and may be beneficial for canoe polo athletes.
... Random allocation sequences were generated by a computer and coded by an independent researcher. On training days, supplements were ingested ~5 minutes after training (Forbes et al., 2014). On nontraining days, supplements were consumed in two equal doses throughout the day. ...
Full-text available
High-intensity interval training (HIIT) has been shown to improve cardiorespiratory fitness, performance, body composition, and insulin sensitivity. Creatine (Cr) supplementation may augment responses to HIIT, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of four weeks of HIIT (three sessions/week) combined with Cr supplementation in recreationally active females. Seventeen females (age = 23 ± 4 yrs; BMI = 23.4 ± 2.4) were randomly assigned to either Cr (Cr; 0.3 g·kg(-1)·d(-1) for 5 d followed by 0.1 g·kg(-1)·d(-1) for 23 days; n=9) or placebo (PLA; n=8). Before and after the intervention, VO2peak, ventilatory threshold (VT), time- trial performance, lean body mass and fat mass, and insulin sensitivity were assessed. HIIT improved VO2peak (Cr = +10.2%; PLA = +8.8%), VT (Cr = +12.7%; PLA = +9.9%), and time- trial performance (Cr = -11.5%; PLA = -11.6%) with no differences between groups (time main effects, all p<0.001). There were no changes over time for fat mass (Cr = -0.3%; PLA = +4.3%), whole-body lean mass (Cr = +0.5%; PLA = -0.9%), or insulin resistance (Cr = +3.9%; PLA = +18.7%). In conclusion, HIIT is an effective way to improve cardiorespiratory fitness, VT, and time-trial performance. The addition of Cr to HIIT did not augment improvements in cardiorespiratory fitness, performance or body composition in recreationally active females.
... Increment of muscle protein synthesis is one of the Cr supplementation effects after resistance training, although it has converted an important point of debate due to tuneless findings of some investigations (51,52). Nevertheless, since more than two decades many studies have revealed that Cr supplementation accompanying a period of resistance training increases muscle fibers size with respect to control subjects (53,54,55,56,57). In addition, in vitro studies have shown an increment in myotubes diameter after Cr exposition with regard to controls (58,59,60). ...
Full-text available
In recent years the research problem in the field of sports supplementation has changed to explain the metabolic mechanisms by which creatine (Cr) administration enhances the performance of certain sports or simply benefits the muscular adaptation. In this review for first time the biochemical mechanisms of Cr ingestion in a cell signaling insight were analyzed, focusing on energetic bioavailability enhancement and optimization of the temporal and spatial buffering of Cr/PCr/CK system. Moreover, intensification in proliferation and differentiation processes of muscle cells (IGF-I/PI3K/Akt-PKB, SPHK1/MAPK/p38/MRFs, mTOR, cellular swelling, mitotic activity of satellite cells, actin polymerization, and myoblast fusion) and inactivation and/or reduction in the expression of ergolitic metabolites (GSK3β, myostatin and AMPK regulation) were examined. In this way, we explained from a metabolic point of view the increase in muscle mass, strength, fatigue resistance, and performance of high intensity sports after Cr monohydrate supplementation.
Full-text available
Consumption of pre-workout supplements (PWS) has increased substantially in recent years. However, dosages of ingredients vary between manufacturers. Therefore, the aim of this study was to analyze ingredients from various products and to survey past and present (4 weeks) consumption behavior. Analysis of ingredients was performed in 30 products according to manufacturer's specifications. Subsequently, online questionnaire was used to assess reasons for taking, timing and dosing of PWS in 39 recreational athletes (4 females; 35 males; 25.15 ± 3.67 years). Most prevalent ingredients in PWS were caffeine, beta-alanine, L-citrulline, L-arginine, L-tyrosine, taurine and creatine. Average dosing per serving were 254mg caffeine (125-410 mg), 2513 mg beta-alanine (500-4000 mg), L-citrulline 3506 mg (500-8000 mg), L-arginine 2726 mg (500-8000 mg), L-tyrosine 1227 mg (150-3000 mg), taurine 1211 mg (90-2500 mg) and creatine 3031 mg (1000-5000 mg). Average values were in (63%) or below (36%) the recommended ergogenic dosage. Major motives for PWS use were improved concentration, increased blood flow and delayed onset of fatigue. Most subjects consumed PWS 1-3 times per month. In most cases consumption took place 15-30 min before training. Manufacturers' recommendations for consumption were generally followed. A large number of subjects (82%) reported minor side effects from PWS consumption (e. g. paresthesia, insomnia, headache). Based on current research only caffeine, L-citrulline, L-arginine and taurine show relevant direct performance-enhancing effects, while the benefit of beta-alanine, L-tyrosine and creatine in PWS seems highly questionable. Dosages of ingredients were safe, but often too low to increase performance.
Full-text available
Nanostructure materials or nanomaterials research takes a materials science-based approach to nanotechnology, leveraging advances in dope or un-doped materials metrology and facile synthesis which have been developed in support of various chemical and nano or micro fabrication research. Nanomaterials (NMs) have unique properties, such as optical, structural, electronic, chemical, or mechanical in every dimensions with nanoscale range. In this chapter, a low-dimensional antimony-doped tin oxide aggregated nanoparticles (ATO NPs) were synthesized using hydrothermal method in alkaline phase. The optical, morphological, and structural properties of ATO NPs were characterized in details using FTIR, UV-Vis, FESEM, XEDS, XPS, TEM and XRD techniques. Flat glassy carbon electrode (GCE) was fabricated with a thin-layer of aggregated ATO NPs by conducting coating binders (5% Nafion) for the development of selective and sensitive enzyme-less creatine (Crt) sensor. Electrochemical responses along with higher sensitivity, large-dynamic range and long-term stability towards Crt were performed by electrochemical I-V approach. The calibration curve was found linear over a wide linear dynamic range of Crt concentration. It is an organized route for the development of non-enzymatic Crt biosensor based on ATO NPs embedded GCE using electrochemical reduction phenomena and significantly applied for the real analysis. As far as we know, this report is the maiden publication on highly sensitive Crt biosensor based on the ATO NPs/GCE. This method could be a pioneer development in Crt sensitive biosensor development using ATO NPs in reliable I-V method for the important biosensor applications with useful doped materials coupled nano-technological system.
Full-text available
This study was performed to compare the effects of creatine supplementation (CR) before vs. after supervised resistance training (RT) in healthy older adults. Participants were randomized to one of two groups: CR-Before (0.1g•kg(-1) creatine before + 0.1g•kg(-1) placebo [rice flour] after RT, n = 11) or CR-After (placebo before + creatine after RT, n = 11). Resistance training (RT) was performed 3 days/week, on nonconsecutive days, for 12 weeks. Prior to and following the study, measures were taken for body composition, maximum strength, muscle protein catabolism, and kidney function. Over the 12-week training period, both groups experienced a significant increase in whole-body lean tissue mass, limb muscle thickness, and upper and lower body strength and a decrease in muscle protein catabolism (p < 0.001), with no differences between groups. There was no change in kidney function over time. Changes in muscle mass or strength are similar when creatine is ingested before or after supervised resistance training in older adults.
Full-text available
Chronic supplementation with creatine monohydrate has been shown to promote increases in total intramuscular creatine, phosphocreatine, skeletal muscle mass, lean body mass and muscle fiber size. Furthermore, there is robust evidence that muscular strength and power will also increase after supplementing with creatine. However, it is not known if the timing of creatine supplementation will affect the adaptive response to exercise. Thus, the purpose of this investigation was to determine the difference between pre versus post exercise supplementation of creatine on measures of body composition and strength. Nineteen healthy recreational male bodybuilders (mean +/- SD; age: 23.1 +/- 2.9; height: 166.0 +/- 23.2 cm; weight: 80.18 +/- 10.43 kg) participated in this study. Subjects were randomly assigned to one of the following groups: PRE-SUPP or POST-SUPP workout supplementation of creatine (5 grams). The PRE-SUPP group consumed 5 grams of creatine immediately before exercise. On the other hand, the POST-SUPP group consumed 5 grams immediately after exercise. Subjects trained on average five days per week for four weeks. Subjects consumed the supplement on the two non-training days at their convenience. Subjects performed a periodized, split-routine, bodybuilding workout five days per week (Chest-shoulders-triceps; Back-biceps, Legs, etc.). Body composition (Bod Pod(R)) and 1-RM bench press (BP) were determined. Diet logs were collected and analyzed (one random day per week; four total days analyzed). 2x2 ANOVA results - There was a significant time effect for fat-free mass (FFM) (F = 19.9; p = 0.001) and BP (F = 18.9; p < 0.001), however, fat mass (FM) and body weight did not reach significance. While there were trends, no significant interactions were found. However, using magnitude-based inference, supplementation with creatine post workout is possibly more beneficial in comparison to pre workout supplementation with regards to FFM, FM and 1-RM BP. The mean change in the PRE-SUPP and POST-SUPP groups for body weight (BW kg), FFM (kg), FM (kg) and 1-RM bench press (kg) were as follows, respectively: Mean +/- SD; BW: 0.4 +/- 2.2 vs 0.8 +/- 0.9; FFM: 0.9 +/- 1.8 vs 2.0 +/- 1.2; FM: -0.1 +/- 2.0 vs -1.2 +/- 1.6; Bench Press 1-RM: 6.6 +/- 8.2 vs 7.6 +/- 6.1.Qualitative inference represents the likelihood that the true value will have the observed magnitude. Furthermore, there were no differences in caloric or macronutrient intake between the groups. Creatine supplementation plus resistance exercise increases fat-free mass and strength. Based on the magnitude inferences it appears that consuming creatine immediately post-workout is superior to pre-workout vis a vis body composition and strength.
Full-text available
Skeletal muscle mass declines with age (i.e., sarcopenia) resulting in muscle weakness and functional limitations. Sarcopenia has been associated with physiological changes in muscle morphology, protein and hormonal kinetics, insulin resistance, inflammation, and oxidative stress. The purpose of this review is to highlight how exercise and nutritional intervention strategies may benefit aging muscle. It is well known that resistance exercise training increases muscle strength and size and evidence also suggests that resistance training can increase mitochondrial content and decrease oxidative stress in older adults. Recent findings suggest that fast-velocity resistance exercise may be an effective intervention for older adults to enhance muscle power and functional capacity. Aerobic exercise training may also benefit aging skeletal muscle by enhancing mitochondrial bioenergetics, improving insulin sensitivity, and/or decreasing oxidative stress. In addition to exercise, creatine monohydrate, milk-based proteins, and essential fatty acids all have biological effects which could enhance some of the physiological adaptations from exercise training in older adults. Additional research is needed to determine whether skeletal muscle adaptations to increased activity in older adults are further enhanced with effective nutritional interventions and whether this is due to enhanced muscle protein synthesis, improved mitochondrial function, and/or a reduced inflammatory response.
Full-text available
The purpose of this study was to compare changes in muscle insulin-like growth factor-I (IGF-I) content resulting from resistance-exercise training (RET) and creatine supplementation (CR). Male (n=24) and female (n=18) participants with minimal resistance-exercise-training experience (=1 year) who were participating in at least 30 min of structured physical activity (i.e., walking, jogging, cycling) 3-5 x/wk volunteered for the study. Participants were randomly assigned in blocks (gender) to supplement with creatine (CR: 0.25 g/kg lean-tissue mass for 7 days; 0.06 g/kg lean-tissue mass for 49 days; n=22, 12 males, 10 female) or isocaloric placebo (PL: n=20, 12 male, 8 female) and engage in a whole-body RET program for 8 wk. Eighteen participants were classified as vegetarian (lacto-ovo or vegan; CR: 5 male, 5 female; PL: 3 male, 5 female). Muscle biopsies (vastus lateralis) were taken before and after the intervention and analyzed for IGF-I using standard immunohistochemical procedures. Stained muscle cross-sections were examined microscopically and IGF-I content quantified using image-analysis software. Results showed that RET increased intramuscular IGF-I content by 67%, with greater accumulation from CR (+78%) than PL (+54%; p=.06). There were no differences in IGF-I between vegetarians and nonvegetarians. These findings indicate that creatine supplementation during resistance-exercise training increases intramuscular IGF-I concentration in healthy men and women, independent of habitual dietary routine.
Sarcopenia refers to the progressive loss of muscle mass and muscle function and is a contributing factor for cachexia, bone loss, and frailty. Resistance training produces several physiological adaptations which improve aging musculoskeletal health, such as increased muscle and bone mass and strength. The combination of creatine supplementation and resistance training may further lead to greater physiological benefits. We performed meta-analyses which indicate creatine supplementation combined with resistance training has a positive effect on aging muscle mass and upper body strength compared to resistance training alone. Creatine also shows promise for improving bone mineral density and indices of bone biology. The combination of creatine supplementation and resistance training could be an effective intervention to improve aging musculoskeletal health.
Sarcopenia, defined as the age-related loss of muscle mass, subsequently has a negative effect on strength, metabolic rate and functionality leading to a reduced quality of life. With the projected increase in life expectancy, the incidence of muscle loss may rise and further drain the health care system, with greater need for hospitalization, treatment, and rehabilitation. Without effective strategies to counteract aging muscle loss, a global health care crisis may be inevitable. Resistance training is well established to increase aging muscle mass and strength. However, muscle and strength loss is still evident in older adults who have maintained resistance training for most of their life, suggesting that other factors such as nutrition may affect aging muscle biology. Supplementing with creatine, a high-energy compound found in red meat and seafood, during resistance training has a beneficial effect on aging muscle. Emerging evidence now suggests that the timing and dosage of creatine supplementation may be important factors for aging muscle accretion. Unfortunately, the long-term effects of different creatine application strategies on aging muscle are relatively unknown.
To determine whether low-dose creatine and protein supplementation during resistance training (RT; 3 d x wk(-1); 10 wk) in older men (59-77 yr) is effective for improving strength and muscle mass without producing potentially cytotoxic metabolites (formaldehyde). Older men were randomized (double-blind) to receive 0.1 g x kg(-1) creatine + 0.3 g x kg(-1) protein (CP; n = 10), creatine (C; n = 13), or placebo (PLA; n = 12) on training days. Measurements before and after RT included lean tissue mass (air-displacement plethysmography), muscle thickness (ultrasound) of elbow, knee, and ankle flexors and extensors, leg and bench press strength, and urinary indicators of cytotoxicity (formaldehyde), myofibrillar protein degradation [3-methylhistidine (3-MH)],and bone resorption [cross-linked N-telopeptides of type I collagen (NTx)]. Subjects in C and CP groups combined experienced greater increases in body mass and total muscle thickness than PLA (P < 0.05). Subjects who received CP increased lean tissue mass (+5.6%) more than C (+2.2%) or PLA (+1.0%; P < 0.05) and increased bench press strength (+25%) to a greater extent than C and PLA combined (+12.5%; P < 0.05). CP and C did not differ from PLA for changes in formaldehyde production (+24% each). Subjects receiving creatine (C and CP) experienced a decrease in 3-MH by 40% compared with an increase of 29% for PLA (P < 0.05) and a reduction in NTx (-27%) versus PLA (+13%; P = 0.05). Low-dose creatine combined with protein supplementation increases lean tissue mass and results in a greater relative increase in bench press but not leg press strength. Low-dose creatine reduces muscle protein degradation and bone resorption without increasing formaldehyde production.
1. The present study was undertaken to test whether creatine given as a supplement to normal subjects was absorbed, and if continued resulted in an increase in the total creatine pool in muscle. An additional effect of exercise upon uptake into muscle was also investigated. 2. Low doses (1 g of creatine monohydrate or less in water) produced only a modest rise in the plasma creatine concentration, whereas 5 g resulted in a mean peak after 1 h of 795 (sd 104) μmol/l in three subjects weighing 76–87 kg. Repeated dosing with 5 g every 2 h sustained the plasma concentration at around 1000 μmol/l. A single 5 g dose corresponds to the creatine content of 1.1 kg of fresh, uncooked steak. 3. Supplementation with 5 g of creatine monohydrate, four or six times a day for 2 or more days resulted in a significant increase in the total creatine content of the quadriceps femoris muscle measured in 17 subjects. This was greatest in subjects with a low initial total creatine content and the effect was to raise the content in these subjects closer to the upper limit of the normal range. In some the increase was as much as 50%. 4. Uptake into muscle was greatest during the first 2 days of supplementation accounting for 32% of the dose administered in three subjects receiving 6 × 5 g of creatine monohydrate/day. In these subjects renal excretion was 40, 61 and 68% of the creatine dose over the first 3 days. Approximately 20% or more of the creatine taken up was measured as phosphocreatine. No changes were apparent in the muscle ATP content. 5. No side effects of creatine supplementation were noted. 6. One hour of hard exercise per day using one leg augmented the increase in the total creatine content of the exercised leg, but had no effect in the collateral. In these subjects the mean total creatine content increased from 118.1 (sd 3.0) mmol/kg dry muscle before supplementation to 148.5 (sd 5.2) in the control leg, and to 162.2 (sd 12.5) in the exercised leg. Supplementation and exercise resulted in a total creatine content in one subject of 182.8 mmol/kg dry muscle, of which 112.0 mmol/kg dry muscle was in the form of phosphocreatine.