Comparison of Creatine Supplementation Before Versus After Supervised Resistance Training in Healthy Older Adults

The role of resistance training and creatine supplementation on oxidative stress, antioxidant defense, muscle strength, and quality of life in older adults

Background

The aim of this study was to evaluate the effect of resistance training (RT) with creatine monohydrate supplementation (CS) on serum levels of 8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA), glutathione peroxidase (GPX), and total antioxidant capacity (TAC) in older adults.

Objectives

This study evaluated the effect of resistance training with creatine monohydrate supplementation on oxidative stress and antioxidant defense, muscle strength and quality of life in older adults.

Methods

We examined 45 non-athlete volunteer older men and women (mean, 68.1 ± 7.2  years old), were randomly selected and divided into three groups of 15: RT with creatine supplementation (RT + CS), RT with placebo (RT + P) and control group. RT protocol was performed for 10  weeks, three sessions per week. Creatine supplement was taken daily at a dose of 0.1 g/kg of body weight, while the placebo group consumed the same amount of starch. Fasting blood samples were taken before the start of program and at the end of the RT period.

Results

In the training groups, after 10  weeks of RT, a significant decrease in MDA and 8 - OHDG as well as a significant increase in serum levels of GPX and TAC were observed (in all cases, p =  0.001). In addition, creatinine levels were enhanced in the RT + CS (p =  0.014). Training intervention also improved quality of life and muscle strength in the experimental groups (p =  0.001), although muscle strength changes were more visible in the RT + CS group than in the RT + P group (p <  0/05).

Conclusion

Regular resistance training can be recommended as a very suitable non-pharmacological approach to strengthen the body's antioxidant system, muscle strength and quality of life in older adults. There are no definite findings on the role of creatine on the antioxidant system and quality of life in older adults, but the use of this supplement in addition to RT can double the amount of strength gained from resistance training.

Effects of creatine monohydrate timing on resistance training adaptations and body composition after 8 weeks in male and female collegiate athletes

Background

Limited research is available on the potential impact of creatine monohydrate administration before or after workouts among athletes. This study aimed to investigate the effects of pre- vs. post-exercise creatine monohydrate supplementation on resistance training adaptations and body composition.

Methods

In a randomized, double-blind, placebo-controlled, parallel design, 34 healthy resistance-trained male and female athletes were randomly assigned and matched according to fat free mass to consume a placebo, or 5-g dose of creatine monohydrate within 1 h before training, or within 1 h after training for 8 weeks, while completing a weekly resistance training program. Participants co-ingested 25-gram doses of both whey protein isolate and maltodextrin along with each assigned supplement dose. Body composition, muscular strength, and endurance, along with isometric mid-thigh pull were assessed before and after the 8-week supplementation period. A 3 × 2 mixed factorial (group x time) ANOVA with repeated measures on time were used to evaluate differences.

Results

All groups experienced similar and statistically significant increases in fat free mass (+1.34 ± 3.48 kg, p = 0.04), upper (+2.21 ± 5.69 kg, p = 0.04) and lower body strength (+7.32 ± 10.01 kg, p &lt; 0.001), and decreases in body mass (−1.09 ± 2.71 kg, p = 0.03), fat mass (−2.64 ± 4.16 kg, p = 0.001), and percent body fat (−2.85 ± 4.39 kg, p &lt; 0.001).

Conclusions

The timing of creatine monohydrate did not exert any additional influence over the measured outcomes.

Micronuclei frequency and renal function markers in gym members: The moderating role of supplement intake

This research investigates the moderating role of dietary supplement intake in the relationship between MNi frequency and renal markers in gym members. A cross-sectional study was carried out with gym members of all sexes, between 20 and 59 years of age, with data on supplement use obtained via questionnaire. Renal markers (urea and creatinine) were assessed by blood collection. Buccal mucosa cells were collected to assess MNi frequency by buccal micronucleus cytome assay. Moderation was tested using multiple linear regression models by PROCESS macro for SPSS. Results showed significant interactions for supplement use (p = 0.001) and supplement type, ergogenic (p = 0.003) and sports food (p = 0.003), with MNi for urea. For creatinine, only supplement use showed interaction with MNi frequency (p = 0.048). In conclusion, supplement intake is a moderator in the relationship between MNi frequency and renal function markers in gym members.

Creatine O'Clock: Does Timing of Ingestion Really Influence Muscle Mass and Performance?

It is well-established that creatine supplementation augments the gains in muscle mass and performance during periods of resistance training. However, whether the timing of creatine ingestion influences these physical and physiological adaptations is unclear. Muscle contractions increase blood flow and possibly creatine transport kinetics which has led some to speculate that creatine in close proximity to resistance training sessions may lead to superior improvements in muscle mass and performance. Furthermore, creatine co-ingested with carbohydrates or a mixture of carbohydrates and protein that alter insulin enhance creatine uptake. The purpose of this narrative review is to (i) discuss the purported mechanisms and variables that possibly justify creatine timing strategies, (ii) to critically evaluate research examining the strategic ingestion of creatine during a resistance training program, and (iii) provide future research directions pertaining to creatine timing.

Anti-Inflammatory and Anti-Catabolic Effects of Creatine Supplementation: A Brief Review

It is well established that creatine supplementation, primarily when combined with resistance training, significantly increases measures of muscle mass and performance (primarily strength). Emerging research also indicates that creatine supplementation may have favorable effects on measures of bone biology. These anabolic adaptations may be related to creatine influencing cellular hydration status, high-energy phosphate metabolism, growth factors, muscle protein kinetics, and the bone remodeling process. Accumulating research also suggests that creatine supplementation has anti-inflammatory and anti-catabolic properties, which may help create a favorable environment for muscle and bone accretion and recovery from exercise. Creatine supplementation has the ability to decrease markers of inflammation and possibly attenuate cancerous tumor growth progression. From a musculoskeletal perspective, there is some evidence to show that creatine supplementation reduces measures of muscle protein catabolism (primarily in males) and bone resorption when combined with resistance training. The purpose of this brief review is to summarize the current body of literature examining the potential anti-inflammatory and anti-catabolic effects of creatine supplementation across various research populations.

Timing of creatine supplementation does not influence gains in unilateral muscle hypertrophy or strength from resistance training in young adults: a within-subject design

BACKGROUND

Creatine supplementation, in close proximity to resistance training sessions, may be an important strategy to augment muscle accretion and strength. The purpose of this study was to examine the effects of creatine supplementation immediately before compared to immediately after unilateral resistance training on hypertrophy and strength.

METHODS

Using a counter-balanced, double-blind, repeated measures within-subject design, ten recreationally active participants (7 males; 3 females; age: 23±5 years; height: 174±9 cm; body mass: 73.5±9.7 kg) were randomized to supplement with creatine monohydrate (0.1 g/kg of body mass) immediately before and placebo immediately after training one side of the body and placebo immediately before and creatine immediately after training the other side of the body on alternate days. Resistance training consisted of elbow flexion and knee extension (3-6 sets at 80% 1-repetition maximum [1-RM]) for 8 weeks. Prior to and following training, muscle thickness (elbow flexors and leg extensors; ultrasonography) and strength (1-RM for the elbow flexors and knee extensors) was assessed.

RESULTS

There was a significant increase over time for muscle thickness, strength, and relative strength (P<0.01), with no differences between creatine ingestion strategies. Total training volume performed was similar between conditions (P=0.56).

CONCLUSIONS

Creatine supplementation, immediately before or immediately after unilateral resistance training, produces similar gains in muscle hypertrophy and strength in young adults.

Timing of Creatine Supplementation around Exercise: A Real Concern?

Creatine has been considered an effective ergogenic aid for several decades; it can help athletes engaged in a variety of sports and obtain performance gains. Creatine supplementation increases muscle creatine stores; several factors have been identified that may modify the intramuscular increase and subsequent performance benefits, including baseline muscle Cr content, type II muscle fibre content and size, habitual dietary intake of Cr, aging, and exercise. Timing of creatine supplementation in relation to exercise has recently been proposed as an important consideration to optimise muscle loading and performance gains, although current consensus is lacking regarding the ideal ingestion time. Research has shifted towards comparing creatine supplementation strategies pre-, during-, or post-exercise. Emerging evidence suggests greater benefits when creatine is consumed after exercise compared to pre-exercise, although methodological limitations currently preclude solid conclusions. Furthermore, physiological and mechanistic data are lacking, in regard to claims that the timing of creatine supplementation around exercise moderates gains in muscle creatine and exercise performance. This review discusses novel scientific evidence on the timing of creatine intake, the possible mechanisms that may be involved, and whether the timing of creatine supplementation around exercise is truly a real concern.

Creatine for Exercise and Sports Performance, with Recovery Considerations for Healthy Populations

Creatine is one of the most studied and popular ergogenic aids for athletes and recreational weightlifters seeking to improve sport and exercise performance, augment exercise training adaptations, and mitigate recovery time. Studies consistently reveal that creatine supplementation exerts positive ergogenic effects on single and multiple bouts of short-duration, high-intensity exercise activities, in addition to potentiating exercise training adaptations. In this respect, supplementation consistently demonstrates the ability to enlarge the pool of intracellular creatine, leading to an amplification of the cell's ability to resynthesize adenosine triphosphate. This intracellular expansion is associated with several performance outcomes, including increases in maximal strength (low-speed strength), maximal work output, power production (high-speed strength), sprint performance, and fat-free mass. Additionally, creatine supplementation may speed up recovery time between bouts of intense exercise by mitigating muscle damage and promoting the faster recovery of lost force-production potential. Conversely, contradictory findings exist in the literature regarding the potential ergogenic benefits of creatine during intermittent and continuous endurance-type exercise, as well as in those athletic tasks where an increase in body mass may hinder enhanced performance. The purpose of this review was to summarize the existing literature surrounding the efficacy of creatine supplementation on exercise and sports performance, along with recovery factors in healthy populations.

Creatine in Health and Disease

Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.

Timing of ergogenic aids and micronutrients on muscle and exercise performance

The timing of macronutrient ingestion in relation to exercise is a purported strategy to augment muscle accretion, muscle and athletic performance, and recovery. To date, the majority of macronutrient nutrient timing research has focused on carbohydrate and protein intake. However, emerging research suggests that the strategic ingestion of various ergogenic aids and micronutrients may also have beneficial effects. Therefore, the purpose of this narrative review is to critically evaluate and summarize the available literature examining the timing of ergogenic aids (caffeine, creatine, nitrates, sodium bicarbonate, beta-alanine) and micronutrients (iron, calcium) on muscle adaptations and exercise performance. In summary, preliminary data is available to indicate the timing of caffeine, nitrates, and creatine monohydrate may impact outcomes such as exercise performance, strength gains and other exercise training adaptations. Furthermore, data is available to suggest that timing the administration of beta-alanine and sodium bicarbonate may help to minimize known untoward adverse events while maintaining potential ergogenic outcomes. Finally, limited data indicates that timed ingestion of calcium and iron may help with the uptake and metabolism of these nutrients. While encouraging, much more research is needed to better understand how timed administration of these nutrients and others may impact performance, health, or other exercise training outcomes.

Supplements with purported effects on muscle mass and strength

PURPOSE

Several supplements are purported to promote muscle hypertrophy and strength gains in healthy subjects, or to prevent muscle wasting in atrophying situations (e.g., ageing or disuse periods). However, their effectiveness remains unclear.

METHODS

This review summarizes the available evidence on the beneficial impacts of several popular supplements on muscle mass or strength.

RESULTS

Among the supplements tested, nitrate and caffeine returned sufficient evidence supporting their acute beneficial effects on muscle strength, whereas the long-term consumption of creatine, protein and polyunsaturated fatty acids seems to consistently increase or preserve muscle mass and strength (evidence level A). On the other hand, mixed or unclear evidence was found for several popular supplements including branched-chain amino acids, adenosine triphosphate, citrulline, β-Hydroxy-β-methylbutyrate, minerals, most vitamins, phosphatidic acid or arginine (evidence level B), weak or scarce evidence was found for conjugated linoleic acid, glutamine, resveratrol, tribulus terrestris or ursolic acid (evidence level C), and no evidence was found for other supplements such as ornithine or α-ketoglutarate (evidence D). Of note, although most supplements appear to be safe when consumed at typical doses, some adverse events have been reported for some of them (e.g., caffeine, vitamins, α-ketoglutarate, tribulus terrestris, arginine) after large intakes, and there is insufficient evidence to determine the safety of many frequently used supplements (e.g., ornithine, conjugated linoleic acid, ursolic acid).

CONCLUSION

 In summary, despite their popularity, there is little evidence supporting the use of most supplements, and some of them have been even proven ineffective or potentially associated with adverse effects.

Effect of Creatine Supplementation Dosing Strategies on Aging Muscle Performance

OBJECTIVE

This study compared the effects of different creatine supplementation dosages, independent of resistance training, on aging muscle performance and functionality.

DESIGN AND PARTICIPANTS

Using a double-blind, repeated measures design, participants were randomized to one of three groups: Creatine-High (CR-H; n=11; 0.3 g/kg/day of creatine + 0.1 g/kg/day of maltodextrin), Creatine-Moderate (CR-M: n=11; 0.1 g/kg/day of creatine + 0.3 g/kg/day of maltodextrin) or Placebo (PLA; n=11; 0.4 g/kg/day of maltodextrin) for 10 consecutive days.

MEASUREMENTS

The primary dependent variables measured at baseline and after supplementation included muscle strength (1-repetition maximum leg press, chest press, hand-grip), muscle endurance (leg press and chest press; maximal number of repetitions performed for 1 set at 80% and 70% baseline 1-repetition maximum respectively), and physical performance (dynamic balance).

RESULTS

There was a significant increase over time for muscle strength (Leg press: CR-H pre 161.5 ± 55.1 kg, post 169.2 ± 59.2 kg; CR-M pre 145.2 ± 47.7 kg, post 151.7 ± 45.0 kg; PLA pre 163.7 ± 51.5 kg, post 178.2 ± 65.6 kg, p = 0.001; Chest press: CR-H pre 57.0 ± 26.2 kg, post 58.8 ± 28.0 kg; CR-M pre 54.5 ± 27.9 kg, post 56.8 ± 30.1 kg; PLA pre 55.1 ± 26.9 kg, post 58.5 ± 30.1 kg, p = 0.001) and endurance (Leg press: CR-H pre 17.1 ± 6.0 reps, post 21.0 ± 7.2 reps; CR-M pre 24.1 ± 11.6 reps, post 29.1 ± 17.0 reps; PLA pre 23.8 ± 9.7 reps, post 29.5 ± 11.9 reps, p = 0. 001; Chest press: CR-H pre 15.6 ± 2.7 reps, post 18.9 ± 2.7 reps; CR-M pre 18.0 ± 5.0 reps, post 19.9 ± 7.1 reps; PLA pre 20.5 ± 6.2 reps, post 21.6 ± 5.5 reps, p = 0. 001), with no other differences.

CONCLUSION

Short-term creatine supplementation, independent of dosage and resistance training, has no effect on aging muscle performance.

The Combination of Physical Exercise with Muscle-Directed Antioxidants to Counteract Sarcopenia: A Biomedical Rationale for Pleiotropic Treatment with Creatine and Coenzyme Q10

Sarcopenia represents an increasing public health risk due to the rapid aging of the world's population. It is characterized by both low muscle mass and function and is associated with mobility disorders, increased risk of falls and fractures, loss of independence, disabilities, and increased risk of death. Despite the urgency of the problem, the development of treatments for sarcopenia has lagged. Increased reactive oxygen species (ROS) production and decreased antioxidant (AO) defences seem to be important factors contributing to muscle impairment. Studies have been conducted to verify whether physical exercise and/or AOs could prevent and/or delay sarcopenia through a normalization of the etiologically relevant ROS imbalance. Despite the strong rationale, the results obtained were contradictory, particularly with regard to the effects of the tested AOs. A possible explanation might be that not all the agents included in the general heading of "AOs" could fulfill the requisites to counteract the complex series of events causing/accelerating sarcopenia: the combination of the muscle-directed antioxidants creatine and coenzyme Q10 with physical exercise as a biomedical rationale for pleiotropic prevention and/or treatment of sarcopenia is discussed.

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine

Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in preventing and/or reducing the severity of injury, enhancing rehabilitation from injuries, and helping athletes tolerate heavy training loads. Additionally, researchers have identified a number of potentially beneficial clinical uses of creatine supplementation. These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan. The purpose of this review is to provide an update to the current literature regarding the role and safety of creatine supplementation in exercise, sport, and medicine and to update the position stand of International Society of Sports Nutrition (ISSN).

Effect of Preexercise Creatine Ingestion on Muscle Performance in Healthy Aging Males

Preexercise creatine supplementation may have a beneficial effect on aging muscle performance. Using a double-blind, repeated measures, crossover design, healthy males (N = 9, 54.8 ± 4.3 years; 92.9 ± 11.5 kg; 179.2 ± 11.1 cm) were randomized to consume creatine (20 g) and placebo (20 g corn starch maltodextrin), on 2 separate occasions (7 days apart), 3 hours before performing leg press and chest press repetitions to muscle fatigue (3 sets at 70% 1-repetition maximum; 1 minute rest between sets). There was a set main effect (p ≤ 0.05) for the leg press and chest press with the number of repetitions performed decreasing similarly for creatine and placebo. These results suggest that a bolus ingestion of creatine consumed 3 hours before resistance exercise has no effect on upper or lower-body muscle performance in healthy aging males.

Timing, Optimal Dose and Intake Duration of Dietary Supplements with Evidence-Based Use in Sports Nutrition

[Purpose]

The aim of the present narrative review was to consider the evidence on the timing, optimal dose and intake duration of the main dietary supplements in sports nutrition, i.e. β-alanine, nitrate, caffeine, creatine, sodium bicarbonate, carbohydrate and protein.

[Methods]

This review article focuses on timing, optimal dose and intake duration of main dietary supplements in sports nutrition.

[Results]

This paper reviewed the evidence to determine the optimal time, efficacy doses and intake duration for sports supplements verified by scientific evidence that report a performance enhancing effect in both situation of laboratory and training settings.

[Conclusion]

Consumption of the supplements are usually suggested into 5 specific times, such as pre-exercise (nitrate, caffeine, sodium bicarbonate, carbohydrate and protein), during exercise (carbohydrate), post-exercise (creatine, carbohydrate, protein), meal time (β-alanine, creatine, sodium bicarbonate, nitrate, carbohydrate and protein), and before sleep (protein). In addition, the recommended dosing protocol for the supplements nitrate and β-alanine are fixed amounts irrespective of body weight, while dosing protocol for sodium bicarbonate, caffeine and creatine supplements are related to corrected body weight (mg/kg bw). Also, intake duration is suggested for creatine and β-alanine, being effective in chronic daily time < 2 weeks while caffeine, sodium bicarbonate are effective in acute daily time (1-3 hours). Plus, ingestion of nitrate supplement is required in both chronic daily time < 28 days and acute daily time (2- 2.5 h) prior exercise.

Effect of creatine supplementation and drop-set resistance training in untrained aging adults

OBJECTIVE

To investigate the effects of creatine supplementation and drop-set resistance training in untrained aging adults. Participants were randomized to one of two groups: Creatine (CR: n=14, 7 females, 7 males; 58.0±3.0yrs, 0.1g/kg/day of creatine+0.1g/kg/day of maltodextrin) or Placebo (PLA: n=17, 7 females, 10 males; age: 57.6±5.0yrs, 0.2g/kg/day of maltodextrin) during 12weeks of drop-set resistance training (3days/week; 2 sets of leg press, chest press, hack squat and lat pull-down exercises performed to muscle fatigue at 80% baseline 1-repetition maximum [1-RM] immediately followed by repetitions to muscle fatigue at 30% baseline 1-RM).

METHODS

Prior to and following training and supplementation, assessments were made for body composition, muscle strength, muscle endurance, tasks of functionality, muscle protein catabolism and diet.

RESULTS

Drop-set resistance training improved muscle mass, muscle strength, muscle endurance and tasks of functionality (p<0.05). The addition of creatine to drop-set resistance training significantly increased body mass (p=0.002) and muscle mass (p=0.007) compared to placebo. Males on creatine increased muscle strength (lat pull-down only) to a greater extent than females on creatine (p=0.005). Creatine enabled males to resistance train at a greater capacity over time compared to males on placebo (p=0.049) and females on creatine (p=0.012). Males on creatine (p=0.019) and females on placebo (p=0.014) decreased 3-MH compared to females on creatine.

CONCLUSIONS

The addition of creatine to drop-set resistance training augments the gains in muscle mass from resistance training alone. Creatine is more effective in untrained aging males compared to untrained aging females.

Creatine supplementation does not alter neuromuscular recovery after eccentric exercise

INTRODUCTION

The purpose of this study was to investigate the effects of creatine (CR) supplementation on recovery after eccentric exercise (ECC).

METHODS

Fourteen men were assigned randomly to ingest 0.3 g/kg of CR or placebo (PL) before and during recovery (48 hours) from 6 sets of 8 repetitions of ECC. Maximal voluntary contraction (MVC), voluntary activation (VA), muscle thickness (MT), electromyography (EMG), contractile properties, and soreness were assessed.

RESULTS

MVC, evoked twitch torque, and rate of torque development decreased for both groups immediately after ECC and recovered at 48 hours. MT increased and remained elevated at 48 hours for both groups. Soreness increased similarly for both groups. EMG activation was higher for CR versus PL only at 48 hours. There were no group differences for torque, total work, or fatigue index during ECC.

CONCLUSIONS

CR supplementation before and during recovery from ECC had no effect on strength, voluntary activation, or indicators of muscle damage. Muscle Nerve 54: 487-495, 2016.

Role of creatine supplementation in exercise-induced muscle damage: A mini review

Muscle damage is induced by both high-intensity resistance and endurance exercise. Creatine is a widely used dietary supplement to improve exercise performance by reducing exercise-induced muscle damage. Many researchers have suggested that taking creatine reduces muscle damage by decreasing the inflammatory response and oxidative stress, regulating calcium homeostasis, and activating satellite cells. However, the underlying mechanisms of creatine and muscle damage have not been clarified. Therefore, this review discusses the regulatory effects of creatine on muscle damage by compiling the information collected from basic science and sports science research.

Strategic creatine supplementation and resistance training in healthy older adults

Creatine supplementation in close proximity to resistance training may be an important strategy for increasing muscle mass and strength; however, it is unknown whether creatine supplementation before or after resistance training is more effective for aging adults. Using a double-blind, repeated measures design, older adults (50–71 years) were randomized to 1 of 3 groups: creatine before (CR-B: n = 15; creatine (0.1 g/kg) immediately before resistance training and placebo (0.1 g/kg cornstarch maltodextrin) immediately after resistance training), creatine after (CR-A: n = 12; placebo immediately before resistance training and creatine immediately after resistance training), or placebo (PLA: n = 12; placebo immediately before and immediately after resistance training) for 32 weeks. Prior to and following the study, body composition (lean tissue, fat mass; dual-energy X-ray absorptiometry) and muscle strength (1-repetition maximum leg press and chest press) were assessed. There was an increase over time for lean tissue mass and muscle strength and a decrease in fat mass (p < 0.05). CR-A resulted in greater improvements in lean tissue mass (Δ 3.0 ± 1.9 kg) compared with PLA (Δ 0.5 ± 2.1 kg; p < 0.025). Creatine supplementation, independent of the timing of ingestion, increased muscle strength more than placebo (leg press: CR-B, Δ 36.6 ± 26.6 kg; CR-A, Δ 40.8 ± 38.4 kg; PLA, Δ 5.6 ± 35.1 kg; chest press: CR-B, Δ 15.2 ± 13.0 kg; CR-A, Δ 15.7 ± 12.5 kg; PLA, Δ 1.9 ± 14.7 kg; p < 0.025). Compared with resistance training alone, creatine supplementation improves muscle strength, with greater gains in lean tissue mass resulting from post-exercise creatine supplementation.

Whey protein and high-volume resistance training in postmenopausal women

OBJECTIVES

To examine the combined effects of whey protein supplementation and low intensity, high-volume resistance training in healthy postmenopausal women.

DESIGN, SETTING AND SUBJECTS

Postmenopausal women (n=12; age: 57 ± 4.7 years, weight: 75 ± 17.4 kg, height: 163 ± 5.5 cm, body mass index: 28.3 ± 7.0) consumed whey protein (4 x 10 gram aliquots) or placebo (maltodextrin) during unilateral resistance training sessions 2 days per week (Monday, Thursday) and consumed the opposite beverage during training the other side of the body on alternating days (Tuesday, Friday) for 10 weeks. Participants performed 3 sets at 30% baseline 1-repetition maximum (1RM) to volitional muscle fatigue for 4 exercises (leg curl, biceps curl, leg extension, triceps extension). Prior to and following training, assessments were made for upper and lower limb lean tissue mass (dual energy x-ray absorptiometry), muscle thickness of the elbow and knee flexors and extensors (ultrasound) and muscle strength (1RM leg curl, biceps curl, leg extension, triceps extension).

RESULTS

There was a significant increase over time for muscle strength (biceps curl, leg extension, triceps extension; P = 0.006) and muscle thickness (elbow flexors and extensors; P = 0.022) with no differences between whey protein and placebo.

CONCLUSIONS

High volume resistance training is effective for improving some indices of muscle mass and strength in postmenopausal women, but the strategic ingestion of whey protein during training sessions does not augment this response.