Effect of 15 days of betaine ingestion on concentric and eccentric force outputs during isokinetic exercise

Effects of 6-Week Betaine Supplementation on Muscular Performance in Male Collegiate Athletes

The purpose of this study was to investigate the effects of 6-week betaine supplementation during a preparatory period of collegiate athletes on muscular power and strength. Sixteen male collegiate athletes received 5 g/day of betaine (betaine group, n = 9) or carboxymethyl cellulose (placebo group, n = 7) for 6 weeks. All participants engaged in their regular training during the experimental period. The overhead medicine-ball throw (OMBT), countermovement jump, and maximal strength (one repetition maximum, 1-RM) on the bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. After supplementation, there were no significant differences between betaine and placebo groups on any variables. Compared to presupplementation, the performance of OMBT and 1-RM of overhead press and half squat in the betaine group had significantly improved (p < 0.05). By contrast, no significant differences were observed in the placebo group before and after supplementation. Blood analysis revealed no negative effect on blood lipid profiles. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.

Effects of short-term betaine supplementation on muscle endurance and indices of endocrine function following acute high-intensity resistance exercise in young athletes

Objective

This study examined the effects of short-term betaine supplementation on muscle endurance, plasma lactate, testosterone and cortisol levels, and the testosterone to cortisol (T/C) ratio in response to acute resistance exercise (RE).

Method

Using a double-blind, crossover study design, 10 handball players (age ± SD = 16 ± 1 yrs) without prior-structured RE experience performed a high-intensity RE session (leg press followed by bench press; 5 sets to volitional fatigue using 80% baseline 1 repetition maximum (1RM)), before and after 14 days of either placebo (maltodextrin) or betaine (2.5 g·d⁻¹) supplementation. A 30-day washout period separated each treatment. 48 h prior to testing sessions, participants recorded their food intake and did not perform strenuous exercise. Venous blood was sampled before supplementation, and before and after each RE session.

Results

After betaine supplementation, participants performed more repetitions (p < 0.001) during the leg press (Betaine: 35.8 ± 4.3; Placebo: 24.8 ± 3.6, Cohen’s d = 2.77) and bench press (Betaine: 36.3 ± 2.6; Placebo: 26.1 ± 3.5, Cohen’s d = 3.34). Betaine resulted in lower post-exercise cortisol (Betaine: 7.6 ± 1.7; Placebo: 13 ± 3.4 µg.dL⁻¹, p = 0.003, generalized eta squared (ηG2) = 0.49) and lactate (Betaine: 5.2 ± 0.3; Placebo: 6 ± 0.3 mmol.L⁻¹, p < 0.001, ηG2 = 0.96) and higher total testosterone (Betaine: 15.2 ± 2.2; Placebo: 8.7 ± 1.7 ng.mL⁻¹, p < 0.001, ηG2 = 0.87) and T/C ratio (Betaine: 0.21 ± 0.05; Placebo: 0.07 ± 0.02, p < 0.001, = 0.82).

Conclusions

Two weeks of betaine supplementation improved upper- and lower-body muscle endurance and influenced indices of endocrine function following an acute session of high-intensity RE in adolescent handball players.

Effects of Betaine Supplementation on Markers of Metabolic Flexibility, Body Composition, and Anaerobic Performance in Active College-Age Females

Betaine (BET) has shown to be effective in improving body composition and performance, although research in women is lacking. This study investigated the effects of BET supplementation on markers of metabolic flexibility, body composition, and anaerobic performance in college females. Twenty-three active subjects with 21.8 ± 3.0 years of age, 66.6 ± 8.8 kg body mass, 1.6 ± 0.1 m height, and 23.2 ± 5.3% body fat performed a graded exercise test on a cycle ergometer consisting of 4 incremental, 3 min stages for collection of fat and carbohydrate oxidation rates. Three 10 s sprint tests were then completed against a resistance of 7.5% of body mass, separated by 2.5 min of recovery. The study comprised 3 phases: (a) pre-supplementation, (b) randomization to supplement for 2-weeks with either 2.4 g/day BET or placebo (parallel design), and (c) post-supplementation. Repeated-measures analysis of variance were conducted to determine interactions or main effects. There were no group differences for substrate oxidation rates (p > 0.05). Although body composition improved pre-post for both groups (p < 0.05), only the BET group experienced a significant increase in fat free mass (p < 0.01; ∼3%). Further, only the BET group experienced improvements to performance such as a higher mean power output during the final sprint (p = 0.02; ∼3%) and a lower RPE during the final stage of the graded exercise test (p = 0.02). Results from this study suggest BET supplementation may improve body composition and some markers of performance during exercise in collegiate women.

Regulation of Cytochrome c Oxidase by Natural Compounds Resveratrol, (-)-Epicatechin, and Betaine

Numerous naturally occurring molecules have been studied for their beneficial health effects. Many compounds have received considerable attention for their potential medical uses. Among them, several substances have been found to improve mitochondrial function. This review focuses on resveratrol, (–)-epicatechin, and betaine and summarizes the published data pertaining to their effects on cytochrome c oxidase (COX) which is the terminal enzyme of the mitochondrial electron transport chain and is considered to play an important role in the regulation of mitochondrial respiration. In a variety of experimental model systems, these compounds have been shown to improve mitochondrial biogenesis in addition to increased COX amount and/or its enzymatic activity. Given that they are inexpensive, safe in a wide range of concentrations, and effectively improve mitochondrial and COX function, these compounds could be attractive enough for possible therapeutic or health improvement strategies.

Effects of Two-Week Betaine Supplementation on Apoptosis, Oxidative Stress, and Aerobic Capacity after Exhaustive Endurance Exercise

This study evaluated the effects of 2 weeks of betaine supplementation on apoptosis, oxidative stress, and aerobic capacity after exhaustive endurance exercise (EEE). A double-blind, crossover, and counterbalanced design was adopted, with 10 healthy male participants asked to consume betaine (1.25 g of betaine mixed with 300 mL of sports beverage, twice per day for 2 weeks) or placebo (300 mL of sports beverage). All participants performed a graded exercise test on a treadmill to determine the maximal oxygen consumption (VO2max) before supplementation and then performed the EEE test at an intensity of 80% VO2max after 2 weeks of supplementation. The time to exhaustion, peak oxygen consumption, maximal heart rate, and average heart rate were recorded during the EEE test. Venous blood samples were drawn before, immediately after, and 3 h after the EEE test to assess apoptosis and the mitochondrial transmembrane potential (MTP) decline of lymphocytes as well as the concentrations of thiobarbituric acid reactive substance and protein carbonyl. The results indicated that lymphocyte apoptosis was significantly higher immediately after and 3 h after EEE than before exercise in participants in the placebo trial. However, lymphocyte apoptosis exhibited no significant differences among the three time points in participants in the betaine trial. Moreover, apoptosis in the betaine trial was significantly lower immediately after and 3 h after exercise compared with the placebo trial. No differences were noted for other variables. Thus, 2 weeks of betaine supplementation can effectively attenuate lymphocyte apoptosis, which is elevated by EEE. However, betaine supplementation exhibited no effects on MTP decline, oxidative stress, or aerobic capacity.

Betaine Supplementation May Improve Heat Tolerance: Potential Mechanisms in Humans

Betaine has been demonstrated to increase tolerance to hypertonic and thermal stressors. At the cellular level, intracellular betaine functions similar to molecular chaperones, thereby reducing the need for inducible heat shock protein expression. In addition to stabilizing protein conformations, betaine has been demonstrated to reduce oxidative damage. For the enterocyte, during periods of reduced perfusion as well as greater oxidative, thermal, and hypertonic stress (i.e., prolonged exercise in hot-humid conditions), betaine results in greater villi length and evidence for greater membrane integrity. Collectively, this reduces exercise-induced gut permeability, protecting against bacterial translocation and endotoxemia. At the systemic level, chronic betaine intake has been shown to reduce core temperature, all-cause mortality, markers of inflammation, and change blood chemistry in several animal models when exposed to heat stress. Despite convincing research in cell culture and animal models, only one published study exists exploring betaine's thermoregulatory function in humans. If the same premise holds true for humans, chronic betaine consumption may increase heat tolerance and provide another avenue of supplementation for those who find that heat stress is a major factor in their work, or training for exercise and sport. Yet, this remains speculative until data demonstrate such effects in humans.

Betaine Supplementation Does Not Improve Muscle Hypertrophy or Strength Following 6 Weeks of Cross-Fit Training

We aim to investigate the effect of 6 weeks of betaine supplementation on body composition and muscle performance during CrossFit© training. Twenty-nine subjects matched for training status (4.16 ± 0.95 day/week) and body fat mass (12.66 ± 4.08%) were randomly assigned to a betaine (BET; N = 14) or placebo group (PLA; N = 15). Body composition and cellular hydration were estimated with skinfolds measurement and bioelectrical impendence before and after 6 weeks of training. Muscle performance was assessed using three different tests: 3-RM back-squat for muscle strength, 2 km rowing test for aerobic capacity and Bergeron Beep Test for anaerobic capacity. Muscle strength assessed during back squat significantly increased in BET (p = 0.04) but not in the PLA group, however, there were no statistical differences between groups. Although not significant, fat mass was reduced in BET compared to PLA. Overall, body composition and cell hydration measurements did not change in response to training or betaine supplementation. Short-term (6 weeks) betaine supplementation supports muscle strength but was not ergogenic for trained subjects to aerobic and anaerobic performance in the CrossFit©-specific test.

Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review

In recent years, a new class of dietary supplements called multi-ingredient pre-workout supplements (MIPS) has increased in popularity. These supplements are intended to be taken prior to exercise and typically contain a blend of ingredients such as caffeine, creatine, beta-alanine, amino acids, and nitric oxide agents, the combination of which may elicit a synergistic effect on acute exercise performance and subsequent training adaptations compared to single ingredients alone. Therefore, the purpose of this article was to review the theoretical rationale and available scientific evidence assessing the potential ergogenic value of acute and chronic ingestion of MIPS, to address potential safety concerns surrounding MIPS supplementation, and to highlight potential areas for future research. Though direct comparisons between formulations of MIPS or between a MIPS and a single ingredient are challenging and often impossible due to the widespread use of "proprietary blends" that do not disclose specific amounts of ingredients in a given formulation, a substantial body of evidence suggests that the acute pre-exercise consumption of MIPS may positively influence muscular endurance and subjective mood, though mixed results have been reported regarding the acute effect of MIPS on force and power production. The chronic consumption of MIPS in conjunction with a periodized resistance training program appears to augment beneficial changes in body composition through increased lean mass accretion. However, the impact of long-term MIPS supplementation on force production, muscular endurance, aerobic performance, and subjective measures is less clear. MIPS ingestion appears to be relatively safe, though most studies that have assessed the safety of MIPS are relatively short (less than eight weeks) and thus more information is needed regarding the safety of long-term supplementation. As with any dietary supplement, the use of MIPS carries implications for the athlete, as many formulations may intentionally contain banned substances as ingredients or unintentionally as contaminants. We suggest that athletes thoroughly investigate the ingredients present in a given MIPS prior to consumption. In conclusion, it appears that multi-ingredient pre-workout supplements have promise as an ergogenic aid for active individuals, though further information is required regarding long-term efficacy and safety in a wider variety of populations.

The effects of chronic betaine supplementation on body composition and performance in collegiate females: a double-blind, randomized, placebo controlled trial

BACKGROUND

Betaine supplementation has been shown to improve body composition and some metrics of muscular performance in young men; but, whether betaine enhances body composition or performance in female subjects is currently unknown. Therefore, the purpose of this study was to investigate the interaction between resistance training adaptation and chronic betaine supplementation in females.

METHODS

Twenty-three young women (21.0 ± 1.4 years, 165.9 ± 6.4 cm, 68.6 ± 11.8 kg) without prior structured resistance training experience volunteered for this study. Body composition (BodPod), rectus femoris muscle thickness (B-mode Ultrasound), vertical jump, back squat 1RM and bench press 1RM were assessed pre- and post-training. Following 1 week of familiarization training, subjects were matched for body composition and squat strength, and randomly assigned to either a betaine (2.5 g/day; n = 11) or placebo (n = 12) group that completed 3 sets of 6-7 exercises per day performed to momentary muscular failure. Training was divided into two lower and one upper body training sessions per week performed on non-consecutive days for 8 weeks, and weekly volume load was used to analyze work capacity.

RESULTS

Significant main effects of time were found for changes in lean mass (2.4 ± 1.8 kg), muscle thickness (0.13 ± 0.08 cm), vertical jump (1.8 ± 1.6 cm), squat 1RM (39.8 ± 14.0 kg), and bench press 1 RM (9.1 ± 7.3 kg); however, there were no significant interactions. A trend (p = .056) was found for greater weekly training volumes for betaine versus placebo. Significant interactions were found for changes in body fat percentage and fat mass: body fat percentage and fat mass decreased significantly more in betaine (- 3.3 ± 1.7%; - 2.0 ± 1.1 kg) compared to placebo (- 1.7 ± 1.6%; - 0.8 ± 1.3 kg), respectively.

CONCLUSIONS

The results of this study indicated that betaine supplementation may enhance reductions in fat mass, but not absolute strength, that accompany a resistance training program in untrained collegiate females.

Effects of Betaine Supplementation on Muscle Strength and Power: A Systematic Review

Ismaeel, A. Effects of betaine supplementation on muscle strength and power: a systematic review. J Strength Cond Res 31(8): 2338-2346, 2017-Betaine (BET) has recently gotten much attention for its potential role as an ergogenic aid and has become a common ingredient in peri-workout dietary supplements. The purpose of this systematic review of the literature was to investigate the effects of BET supplementation on muscular strength and power. A computerized literature search of 3 databases (PubMed, MEDLINE, and Scopus) was performed. Included in the review were randomized controlled trials that measured muscle strength, power, or both measures in healthy participants. Quality was assessed using the PEDro scale. Seven trials were identified, and quality assessment showed that all were of "excellent quality." Only 2 of the studies reported increases in strength or power after supplementation with BET. The remaining 5 studies showed no change in any strength or power outcome measures with BET supplementation. This review highlights the lack of evidence for a clear ergogenic effect of BET supplementation on strength and power performance. However, because 2 studies did identify increases of up to 24.61% on strength and power as a result of BET supplementation, additional studies are necessary to evaluate its effectiveness.

The Effects of Accentuated Eccentric Loading on the Drop Jump Exercise and the Subsequent Postactivation Potentiation Response

The aims of this study were (a) to investigate the acute effects of different drop jump (DJ) accentuated eccentric loading (AEL) protocols and (b) to investigate the effect of these AEL DJ protocols on subsequent countermovement jump (CMJ) performance. The subjects were 12 strength-trained athletes; initially, baseline CMJ performance was assessed and individual optimal DJ drop height identified. In subsequent weeks, subjects completed 1 set of 5 DJs with no additional load or an AEL of 10, 20, or 30% of their individual body mass (BM) using dumbbells to provide the extra load. After the AEL DJ protocols, 3 CMJs were completed after 2, 6, and 12 minutes rest. A generalized linear mixed model was used to investigate the effects of AEL load and time post-DJs on CMJ height, peak power, and ground reaction force. The 20% AEL condition resulted in greater CMJ height in comparison with all other conditions (p < 0.001). CMJ height was significantly greater after 2 and 6 minutes rest compared with 12 minutes (p < 0.001 and p ≤ 0.05 respectively). Greater peak power was also found during the CMJs after the 20% AEL condition compared with baseline, BM, and 10% AEL (p ≤ 0.05). In conclusion, 5 DJs with 20% AEL followed by a 2 minutes recovery period resulted in significant enhancement in CMJ height and peak power.

Betaine in the Brain: Characterization of Betaine Uptake, its Influence on Other Osmolytes and its Potential Role in Neuroprotection from Osmotic Stress

Betaine (N-trimethylglycine), a common osmolyte, has received attention because of the number of clinical reports associating betaine supplementation with improved cognition, neuroprotection and exercise physiology. However, tissue analyses report little accumulation of betaine in brain tissue despite the presence of betaine/GABA transporters (BGT1) at the blood brain barrier and in nervous tissue, calling into question whether betaine influences neuronal function directly or indirectly. Therefore, the focus of this study was to determine what capacity nervous tissue has to accumulate betaine, specifically in the hippocampus, a region of the brain associated with learning and memory and one that is particularly susceptible to damage (e.g., seizure activity). Here we report that hippocampal slices actively accumulate betaine in a time, dose and osmolality dependent manner, resulting in peak intracellular concentrations four times extracellular concentrations within 8 h. Our data also indicate that betaine uptake differentially influences the accumulation of other osmolytes. Under isosmotic conditions, betaine uptake minimally impacted some osmolytes (e.g., glycerylphosphorylcholine and glutamate) while significantly reducing others (taurine, creatine, and myo-inositol). Under osmotic stress (hyperosmotic) conditions, we observed dramatic changes in osmolytes like glycine and glutamine-key players in inhibitory neurotransmission-and little change in osmolytes such as taurine, creatine and myo-inositol when betaine was available. These data suggest that betaine may influence pathways of inhibitory neurotransmitter production/recycling in addition to serving as an osmolyte and metabolic intermediate. In sum, our data provide detailed characterization of betaine uptake in the hippocampus that implicates betaine in the modulation of hippocampal neurophysiology and neuroprotection.

Ingestion of a Nitric Oxide Enhancing Supplement Improves Resistance Exercise Performance

Mosher, SL, Sparks, SA, Williams, EL, Bentley, DJ, and Mc Naughton, LR. Ingestion of a nitric oxide enhancing supplement improves resistance exercise performance. J Strength Cond Res 30 (12): 3520-3524, 2016-Studies have established that supplementation of nitrate increases nitric oxide which in turn improves exercise performance. The current study aimed to investigate the effects of nitrate ingestion on performance of bench press resistance exercise until failure. Twelve recreationally active (age, 21 ± 2 years, height, 177.2 ± 4.0 cm, weight, 82.49 ± 9.78 kg) resistance-trained men participated in the study. The study used a double-blind, randomized cross-over design, where participants ingested either 70 ml of "BEET It Sport" nitrate shot containing 6.4 millimoles (mmol·L) or 400 mg of nitrate or a blackcurrant placebo drink. Participants completed a resistance exercise session, consisting of bench press exercise at an intensity of 60% of their established 1 repetition maximum (1RM), for 3 sets until failure with 2 minutes rest interval between sets. The repetitions completed, total weight lifted, local and general rate of perceived exertion (RPE), and blood lactate were all measured. The results showed a significant difference in repetitions to failure (p ≤ 0.001) and total weight lifted (p ≤ 0.001). However, there were no significant difference between blood lactate over the 2 trials (p = 0.238), and no difference in Local (p = 0.807) or general (p = 0.420) indicators of fatigue as measured by RPE. This study demonstrates that nitrate supplementation has the potential to improve resistance training performance and work output compared with a placebo.

Electromyographic amplitude vs. concentric and eccentric squat force relationships for monoarticular and biarticular thigh muscles

This study examined the linearity of the electromyographic (EMG) amplitude vs. concentric and eccentric squat force relationships for monoarticular and biarticular thigh muscles. Fourteen resistance-trained men (mean age ± SD: 22 ± 2 years; estimated thigh muscle cross-sectional area: 221.9 ± 22.7 cm) performed concentric and eccentric squats using a novel testing device from 10 to 90% of their maximum average force. Surface EMG signals were detected from the right vastus lateralis, rectus femoris, and biceps femoris. Linear regression was used to examine the relationships between EMG amplitude and force, and repeated measures analyses of variance were used to assess differences among the muscles. Moderate-to-high coefficients of determination were found for the vastus lateralis for both concentric and eccentric testings (r = 0.587-0.992). For the biceps femoris, the mean linear slope coefficient was significantly greater for concentric vs. eccentric testing (0.044 vs. 0.013 μV RMS·N; p = 0.002; effect size = 1.44). Although EMG amplitude for the vastus lateralis and rectus femoris increased with changes in eccentric force output, the electrical activity of the biceps femoris remained stable. These results demonstrated that the EMG amplitude vs. force relationships for the vastus lateralis were linear, despite the fact that force production during the squat is related to the activation of muscles that must simultaneously function as agonists and antagonists. Our findings for eccentric force testing are in agreement with investigations showing reduced hip extensor activity during concurrent extension at the hip and knee joints.

Consistency of peak and mean concentric and eccentric force using a novel squat testing device

The ability to examine force curves from multiple-joint assessments combines many of the benefits of dynamic constant external resistance exercise and isokinetic dynamometry. The purpose of this investigation was to examine test-retest reliability statistics for peak and mean force using the Exerbotics eSQ during maximal concentric and eccentric squats. Seventeen resistance-trained men (mean±SD age=21±2 years) visited the laboratory on two occasions. For each trial, the subjects performed two maximal concentric and eccentric squats, and the muscle actions with the highest force values were analyzed. There were no mean differences between the trials (P>.05), and the effect sizes were <0.12. When the entire force curve was examined, the intraclass correlation coefficients (model 2,1) and standard errors of measurement, respectively, were concentric peak force=0.743 (8.8%); concentric mean force=0.804 (6.0%); eccentric peak force=0.696 (10.6%); eccentric mean force=0.736 (9.6%). These findings indicated moderate-to-high reliability for the peak and mean force values obtained from the Exerbotics eSQ during maximal squat testing. The analysis of force curves from multiple-joint testing provides researchers and practitioners with a reliable means of assessing performance, especially during concentric muscle actions.

Metabolic crosstalk between choline/1-carbon metabolism and energy homeostasis

There are multiple identified mechanisms involved in energy metabolism, insulin resistance and adiposity, but there are here-to-fore unsuspected metabolic factors that also influence these processes. Studies in animal models suggest important links between choline/1-carbon metabolism and energy homeostasis. Rodents fed choline deficient diets become hypermetabolic. Mice with deletions in one of several different genes of choline metabolism have phenotypes that include increased metabolic rate, decreased body fat/lean mass ratio, increased insulin sensitivity, decreased ATP production by mitochondria, or decreased weight gain on a high fat diet. In addition, farmers have recognized that the addition of a metabolite of choline (betaine) to cattle and swine feed reduces body fat/lean mass ratio. Choline dietary intake in humans varies over a > three-fold range, and genetic variation exists that modifies individual requirements for this nutrient. Although there are some epidemiologic studies in humans suggesting a link between choline/1-carbon metabolism and energy metabolism, there have been no controlled studies in humans that were specifically designed to examine this relationship.

Sex comparisons for relative peak torque and electromyographic mean frequency during fatigue

PURPOSE

This study compared the relative peak torque and normalized electromyographic (EMG) mean frequency (MNF) responses during fatiguing isokinetic muscle actions for men versus women.

METHOD

Twenty men (Mage +/- SD = 22 +/- 2 years) and 20 women (Mage +/- SD = 22 +/- 1 years) performed 50 maximal concentric isokinetic muscle actions of the leg extensors at a velocity of 180 degrees/s while surface EMG signals were detected from the vastus lateralis, rectus femoris, and vastus medialis. The dependent variables were initial, final, and average peak torque; percent decline; the estimated percentage of fast-twitch fibers for the vastus lateralis; and the linear slope coefficients and y-intercepts for normalized EMG MNF versus repetition number. The data were analyzed with independent-samples t tests and 2-way mixed-factorial analyses of variance.

RESULTS

The mean initial, final, and average peak torque values for men were greaterthan those for women. There were no mean differences for percent decline and the estimated percentage of fast-twitch fibers for the vastus lateralis. There were also no sex differences for the linear slope coefficients, but there were differences among the muscles (vastus medialis > vastus lateralis > rectus femoris). The mean y-intercept for the vastus lateralis for men was greater than that for women.

CONCLUSIONS

Men demonstrated greater peak torque values than those for women, but the declines in peak torque and normalized EMG MNF were similar between thesexes. The vastus medialis was more fatigue-resistant than both the vastus lateralis and rectus femoris.

Effects of betaine on body composition, performance, and homocysteine thiolactone

Background

This study investigated the effects of long term betaine supplementation on body composition, performance, and homocysteine thiolactone (HCTL) in experienced strength trained men.

Methods

Twenty-three subjects were matched for training experience (4.8 ± 2.3 years) and body fat percentage (BF%: 16.9 ± 8.0%), randomly assigned to either a placebo (PL; n = 12) or betaine group (BET; n = 11; 2.5 g/day), and completed a 6 week periodized training program consisting of 3 two-week micro-cycles. Bench press and back squat training volumes were recorded and changes in training volume were assessed at each micro-cycle. Fasting urine was collected at baseline (BL), weeks 2, 4 and 6, and assayed for HCTL. Subjects were tested prior to and following 6 weeks of treatment. Arm and thigh cross sectional area (CSA) was estimated via girth and skin fold measurements. Body density was estimated via skin fold calipers and used to estimate BF%, fat mass (FM), and lean body mass (LBM). Performance was assessed via vertical jump (VJ), bench press 1 RM (BP), and back squat 1 RM (BS).

Results

Arm CSA increased significantly (p < .05) in BET but not PL. No differences existed between group and time for changes in thigh CSA. Back squat training volume increased significantly (p < .05) for both groups throughout training. Bench press training volume was significantly (p < .05) improved for BET compared to PL at microcycles one and three. Body composition (BF%, FM, LBM) improved significantly (p < .05) in BET but not PL. No differences were found in performance variables (BP, BS, VJ) between groups, except there was a trend (p = .07) for increased VJ power in BET versus PL. A significant interaction (p < .05) existed for HCTL, with increases from BL to week 2 in PL, but not BET. Additionally, HCTL remained elevated at week 4 in PL, but not BET.

Conclusion

Six-weeks of betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power (p = .07) but not strength.

Betaine supplement enhances skeletal muscle differentiation in murine myoblasts via IGF-1 signaling activation

BACKGROUND

Betaine (BET) is a component of many foods, including spinach and wheat. It is an essential osmolyte and a source of methyl groups. Recent studies have hypothesized that BET might play a role in athletic performance. However, BET effects on skeletal muscle differentiation and hypertrophy are still poorly understood.

METHODS

We examined BET action on neo myotubes maturation and on differentiation process, using C2C12 murine myoblastic cells. We used RT2-PCR array, Western blot and immunofluorescence analysis to study the BET effects on morphological features of C2C12 and on signaling pathways involved in muscle differentiation and hypertrophy.

RESULTS

We performed a dose-response study, establishing that 10 mM BET was the dose able to stimulate morphological changes and hypertrophic process in neo myotubes. RT2-PCR array methodology was used to identify the expression profile of genes encoding proteins involved in IGF-1 pathway. A dose of 10 mM BET was found to promote IGF-1 receptor (IGF-1 R) expression. Western blot and immunofluorescence analysis, performed in neo myotubes, pointed out that 10 mM BET improved IGF-1 signaling, synthesis of Myosin Heavy Chain (MyHC) and neo myotubes length.

CONCLUSIONS

Our findings provide the first evidence that BET could promote muscle fibers differentiation and increase myotubes size by IGF-1 pathway activation, suggesting that BET might represent a possible new drug/integrator strategy, not only in sport performance but also in clinical conditions characterized by muscle function impairment.