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Betaine supplementation improves CrossFit performance and increases testosterone levels, but has no influence on Wingate power: randomized crossover trial.
Zawieja, E, Durkalec-Michalski, K, Sadowski, M, Główka, N, Chmurzynska, A
Journal of the International Society of Sports Nutrition. 2023;20(1):2231411
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Betaine nutritional supplementation is often used by individuals who want to increase their athletic performance as it has been hypothesised to increase muscle strength and power. However, studies on this have been inconsistent. One study has shown no benefit of supplementation on muscle strength, however two have shown a benefit of betaine on muscle endurance, which is essential to perform cross fit-based exercises. The aim of this study was to determine the effect of betaine on body composition, cross fit performance, muscle power, and certain hormones after 3 weeks of supplementation. The results showed that workout performance was improved with betaine supplementation, however this did not translate into changes in body composition. Testosterone levels were increased by betaine supplementation. Individuals who had genetic variations that meant that their betaine requirements may be higher showed no benefit of taking betaine for cross-fit performance or any of the outcomes measured. There was also no difference to any of the outcomes with differing betaine doses (2.5 and 5.0 g/d). It was concluded that betaine supplementation may improve cross-fit performance and testosterone levels. However individuals with genetic variations that may mean their requirements for betaine are higher showed no benefit of supplementation on cross-fit performance.
Abstract
BACKGROUND Because betaine (BET) supplementation may improve muscular strength and endurance, it seems plausible that BET will also influence CrossFit performance (CF). PURPOSE The aim of this study was to evaluate the effects of three weeks of BET supplementation on body composition, CF performance, muscle power in the Wingate anaerobic test (WAnT), and the concentrations of selected hormones. The secondary aims were to analyze the effectiveness of two different BET doses (2.5 and 5.0 g/d) and their interaction with the methylenetetrahydrofolate reductase (MTHFR) genotype. METHODS The study was designed in a double-blinded randomized cross-over fashion. Forty-three CF practitioners completed the entire study. CF performance was measured using the Fight Gone Bad (FGB) workout and muscle power was evaluated in a 30-second WAnT. Body composition was determined by air-displacement plethysmography. Blood was drawn to assess hormone concentrations. The C677T single nucleotide polymorphism (rs180113) in the MTHFR gene was analyzed. RESULTS FGB total improved with BET by 8.7 ± 13.6% (p < 0.001), but no significant changes were observed with placebo (- 0.4 ± 10.0%, p = 0.128). No changes were also observed in WAnT and body composition. After BET supplementation testosterone concentration increased by 7.0 ± 15.4% with BET (p = 0.046) (no change with placebo: 1.5 ± 19.6%, p = 0.884) but had no effect on concentrations of insulin-like growth factor or cortisol. Finally, there were no significant interactions between MTHFR genotype and BET dose in any outcome. CONCLUSIONS BET supplementation may improve CF performance and increase testosterone concentration. However, there was no evidence of a difference between dosages (2.5 and 5.0 g/d) and MTHFR genotypes. The trial was registered on clinicaltrials.gov (NCT03702205) on 10 October 2018.
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Effects of Hyperbaric Oxygen Therapy on Mitochondrial Respiration and Physical Performance in Middle-Aged Athletes: A Blinded, Randomized Controlled Trial.
Hadanny, A, Hachmo, Y, Rozali, D, Catalogna, M, Yaakobi, E, Sova, M, Gattegno, H, Abu Hamed, R, Lang, E, Polak, N, et al
Sports medicine - open. 2022;8(1):22
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Hyperbaric oxygen therapy (HBOT) utilizes 100% oxygen in an environmental pressure higher than one absolute atmosphere. The aim of this study was to evaluate the effect of an intermittent HBOT protocol on maximal physical performance and its effect on mitochondrial function in middle-aged master athletes. This study is a double-blind, randomized, 1:1 ratio, placebo-controlled study of healthy middle-aged master athletes. Thirty-seven healthy master athletes, aged 40–50, who performed aerobic sports at least four times a week at moderate-high performance were enrolled in the study. Results show that HBOT may significantly enhance physical performance beyond training in healthy master athletes. Moreover, HBOT may directly improve mitochondrial respiration and increase mitochondrial mass. Thus, the main improvements include maximal oxygen consumption, power and the anaerobic threshold. Authors conclude that HBOT can enhance physical performance in healthy adults.
Abstract
INTRODUCTION Hyperbaric oxygen therapy (HBOT) has been used to increase endurance performance but has yet to be evaluated in placebo-controlled clinical trials. The current study aimed to evaluate the effect of an intermittent HBOT protocol on maximal physical performance and mitochondrial function in middle-aged master athletes. METHODS A double-blind, randomized, placebo-controlled study on 37 healthy middle-aged (40-50) master athletes was performed between 2018 and 2020. The subjects were exposed to 40 repeated sessions of either HBOT [two absolute atmospheres (ATA), breathing 100% oxygen for 1 h] or SHAM (1.02ATA, breathing air for 1 h). RESULTS Out of 37 athletes, 16 HBOT and 15 SHAM allocated athletes were included in the final analysis. Following HBOT, there was a significant increase in the maximal oxygen consumption (VO2Max) (p = 0.010, effect size(es) = 0.989) and in the oxygen consumption measured at the anaerobic threshold (VO2AT)(es = 0.837) compared to the SHAM group. Following HBOT, there were significant increases in both maximal oxygen phosphorylation capacity (es = 1.085, p = 0.04), maximal uncoupled capacity (es = 0.956, p = 0.02) and mitochondrial mass marker MTG (p = 0.0002) compared to the SHAM sessions. CONCLUSION HBOT enhances physical performance in healthy middle-age master athletes, including VO2max, power and VO2AT. The mechanisms may be related to significant improvements in mitochondrial respiration and increased mitochondrial mass. Trial Registration ClinicalTrials.gov Identifier: https://clinicaltrials.gov/ct2/show/NCT03524989 (May 15, 2018).
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Comparing Acute, High Dietary Protein and Carbohydrate Intake on Transcriptional Biomarkers, Fuel Utilisation and Exercise Performance in Trained Male Runners.
Furber, M, Pyle, S, Roberts, M, Roberts, J
Nutrients. 2021;13(12)
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Dietary modification to improve exercise endurance has become a popular strategy. The reduction of carbohydrates to enhance adaptations due to training has been shown on a cellular level. In low carbohydrate diets, fat is the usual substitute, however long-term adherence to this is often difficult. Using protein instead of fat may be an alternative, but there is little research on this. This study aimed to investigate the impact of a short-term high-protein, reduced carbohydrate diet compared to a high-carbohydrate diet in combination with endurance running on exercise performance and cellular adaptations. The results showed that any cellular adaptations were due to fuel availability, rather than the fuel type and that a high protein diet compromised high intensity exercise performance. It was concluded that a high-protein, low-carbohydrate diet in combination with endurance training is of no benefit to endurance running performance. This study could be used by healthcare professionals to recommend that athletes and especially runners who wish to improve endurance do not switch to a high-protein, low carbohydrate diet and that other dietary modifications are investigated.
Abstract
Manipulating dietary macronutrient intake may modulate adaptive responses to exercise, and improve endurance performance. However, there is controversy as to the impact of short-term dietary modification on athletic performance. In a parallel-groups, repeated measures study, 16 trained endurance runners (maximal oxygen uptake (V˙O2max): 64.2 ± 5.6 mL·kg-1·min-1) were randomly assigned to, and provided with, either a high-protein, reduced-carbohydrate (PRO) or a high-carbohydrate (CHO) isocaloric-matched diet. Participants maintained their training load over 21-consecutive days with dietary intake consisting of 7-days habitual intake (T1), 7-days intervention diet (T2) and 7-days return to habitual intake (T3). Following each 7-day dietary period (T1-T3), a micro-muscle biopsy was taken for assessment of gene expression, before participants underwent laboratory assessment of a 10 km treadmill run at 75% V˙O2max, followed by a 95% V˙O2max time to exhaustion (TTE) trial. The PRO diet resulted in a modest change (1.37-fold increase, p = 0.016) in AMPK expression, coupled with a significant increase in fat oxidation (0.29 ± 0.05 to 0.59 ± 0.05 g·min-1, p < 0.0001). However, a significant reduction of 23.3% (p = 0.0003) in TTE post intervention was observed; this reverted back to pre levels following a return to the habitual diet. In the CHO group, whilst no change in sub-maximal fuel utilisation occurred at T2, a significant 6.5% increase in TTE performance (p = 0.05), and a modest, but significant, increase in AMPK (p = 0.042) and PPAR (p = 0.029) mRNA expression compared to T1 were observed; with AMPK (p = 0.011) and PPAR (p = 0.044) remaining significantly elevated at T3. In conclusion, a 7-day isocaloric high protein diet significantly compromised high intensity exercise performance in trained runners with no real benefit on gene markers of training adaptation. A significant increase in fat oxidation during submaximal exercise was observed post PRO intervention, but this returned to pre levels once the habitual diet was re-introduced, suggesting that the response was driven via fuel availability rather than cellular adaptation. A short-term high protein, low carbohydrate diet in combination with endurance training is not preferential for endurance running performance.
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Combined aerobic exercise and high-intensity respiratory muscle training in patients surgically treated for non-small cell lung cancer: a pilot randomized clinical trial.
Messaggi-Sartor, M, Marco, E, Martínez-Téllez, E, Rodriguez-Fuster, A, Palomares, C, Chiarella, S, Muniesa, JM, Orozco-Levi, M, Barreiro, E, Güell, MR
European journal of physical and rehabilitation medicine. 2019;55(1):113-122
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Lung cancer treatment initiates a deconditioning storm that further reduces the capacity to deliver and utilize oxygen and metabolic substrates during exercise, contributing to poor cardiorespiratory fitness. The main aim of this study was to assess the impact of aerobic exercise with inspiratory and expiratory muscle training on cardiovascular fitness and respiratory muscle dysfunction in non-small cell lung cancer patients. The study is a two-centre, prospective, single-blind, pilot randomized controlled trial. The eligible patients were randomly assigned to the exercise (n=16) or control groups (n=21). Study results showed strong improvement in respiratory muscle strength and exercise capacity following high-intensity inspiratory and expiratory muscle training. Authors conclude that structured and supervised exercise interventions should be recommended to patients with lung cancer.
Abstract
BACKGROUND Lung resection surgery further decreases exercise capacity and negatively affects respiratory muscle function in patients with non-small cell lung cancer (NSCLC). The best design for exercise interventions in these patients has not been determined yet. AIM: To assess the impact of aerobic exercise and high-intensity respiratory muscle training on patient outcomes following lung cancer resection surgery. DESIGN Prospective, single-blind, pilot randomized controlled trial. SETTING Outpatient cardiopulmonary rehabilitation unit of two university hospitals. POPULATION Thirty-seven patients with NSCLC after tumor resection. METHODS Patients were randomly assigned to exercise training or usual post-operative care. The training program consisted of aerobic exercises and high-intensity respiratory muscle training (24 supervised sessions, 3 per week, 8 weeks). Primary outcome was exercise capacity assessed with peak oxygen uptake (VO2peak) during cardiopulmonary exercise test. Secondary outcomes included changes in respiratory muscle strength, levels of serum insulin growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3), and quality of life assessed with the European Organization for Research and Treatment of Cancer (EORTC QLQ-C30) questionnaire. RESULTS The 8-week training program was associated with significant improvement in VO2peak (2.13 mL/Kg/min [95%CI 0.06 to 4.20]), maximal inspiratory and expiratory pressures (18.96 cmH2O [95% CI 2.7 to 24.1] and 18.58 cmH2O [95% CI 4.0 to 33.1], respectively) and IGFBP-3 (0.61 µg/mL [%95 CI 0.1 to 1.12]). No significant differences were observed in the EORTC QLQ-C30. CONCLUSIONS An 8-week exercise program consisting of aerobic exercise and high-intensity respiratory muscle training improved exercise capacity, respiratory muscle strength, and serum IGFBP-3 levels in NSCLC patients after lung resection. There was no impact on the other outcomes assessed. CLINICAL REHABILITATION IMPACT A combination of aerobic exercise and respiratory muscle training could be included in the rehabilitation program of deconditioned patients with NSCLC after lung resection surgery.
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Effects of Low Versus Moderate Glycemic Index Diets on Aerobic Capacity in Endurance Runners: Three-Week Randomized Controlled Crossover Trial.
Durkalec-Michalski, K, Zawieja, EE, Zawieja, BE, Jurkowska, D, Buchowski, MS, Jeszka, J
Nutrients. 2018;10(3)
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During athletic performance, adequate amounts of carbohydrates are required to prolong the onset of fatigue. Research on whether the glycaemic index (GI) of ingested carbohydrates effects performance has been explored but has produced equivocal results. The aim of this randomised crossover study was to assess the effect of low- and moderate- GI diets on the aerobic capacity and endurance performance in 21 runners. Participants consumed a low- and moderate- GI, high carbohydrate and nutrient balanced diets for three weeks each with a two-week washout period. Aerobic capacity and body composition were measured at the beginning and end of each diet period through various athletic performance tests. This study found that after a low-GI, high-carbohydrate diet, improvements were seen in time to exhaustion and running performance. Gas exchange was improved by both diets. The low-GI carbohydrate diet helped athletes to maintain a more stable blood glucose concentration during exertion tests. Based on these results the authors suggest considering GI when planning a diet for performance athletes, and also urge further research be completed to better understand the effects of long-term GI diets with regards to exercise performance.
Abstract
The glycemic index (GI) of ingested carbohydrates may influence substrate oxidation during exercise and athletic performance. Therefore, the aim of this study was to assess the effect of low- and moderate-GI three-week diets on aerobic capacity and endurance performance in runners. We conducted a randomized crossover feeding study of matched diets differing only in GI (low vs. moderate) in 21 endurance-trained runners. Each participant consumed both, low- (LGI) and moderate-GI (MGI) high-carbohydrate (~60%) and nutrient-balanced diets for three weeks each. At the beginning and end of each diet, participants had their aerobic capacity and body composition measured and performed a 12-min running test. After LGI, time to exhaustion during incremental cycling test (ICT) and distance covered in the 12-min run were significantly increased. The MGI diet led to an increase in maximal oxygen uptake ( V ˙ O₂max), but no performance benefits were found after the MGI diet. The LGI and MGI diets improved time and workload at gas exchange threshold (GET) during ICT. The results indicate that a three-week high-carbohydrate LGI diet resulted in a small but significant improvement in athletic performance in endurance runners. Observed increase in V ˙ O₂max on MGI diet did not affect performance.
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Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.
Moro, T, Tinsley, G, Bianco, A, Marcolin, G, Pacelli, QF, Battaglia, G, Palma, A, Gentil, P, Neri, M, Paoli, A
Journal of translational medicine. 2016;14(1):290
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Time-restricted feeding (TRF) allows subjects to consume ad libitum energy intake within a defined window of time, which means a fasting window of 12–21 h per day is employed. The aim of the present study was to investigate the effects of an isoenergetic TRF protocol on body composition, athletic performance, and metabolic factors during resistance training in healthy resistance trained males. The study enrolled thirty-four resistance-trained males. The participants were randomly assigned to a TRF group (n = 17) or standard diet group (n = 17). Training was standardized for both groups. Results indicate that after 8 weeks, a significant decrease in fat mass was observed in the TRF group, while fat-free mass was maintained in both groups. The same trend was observed for arm and thigh muscle cross-sectional area. Leg press maximal strength increased significantly, but no difference was present between treatments. Authors conclude that TRF can maintain muscle mass, reducing body fat, and reducing inflammation markers and anabolic hormones. This kind of regimen could be adopted by athletes during maintenance phases of training in which the goal is to maintain muscle mass while reducing fat mass.
Abstract
BACKGROUND Intermittent fasting (IF) is an increasingly popular dietary approach used for weight loss and overall health. While there is an increasing body of evidence demonstrating beneficial effects of IF on blood lipids and other health outcomes in the overweight and obese, limited data are available about the effect of IF in athletes. Thus, the present study sought to investigate the effects of a modified IF protocol (i.e. time-restricted feeding) during resistance training in healthy resistance-trained males. METHODS Thirty-four resistance-trained males were randomly assigned to time-restricted feeding (TRF) or normal diet group (ND). TRF subjects consumed 100 % of their energy needs in an 8-h period of time each day, with their caloric intake divided into three meals consumed at 1 p.m., 4 p.m., and 8 p.m. The remaining 16 h per 24-h period made up the fasting period. Subjects in the ND group consumed 100 % of their energy needs divided into three meals consumed at 8 a.m., 1 p.m., and 8 p.m. Groups were matched for kilocalories consumed and macronutrient distribution (TRF 2826 ± 412.3 kcal/day, carbohydrates 53.2 ± 1.4 %, fat 24.7 ± 3.1 %, protein 22.1 ± 2.6 %, ND 3007 ± 444.7 kcal/day, carbohydrates 54.7 ± 2.2 %, fat 23.9 ± 3.5 %, protein 21.4 ± 1.8). Subjects were tested before and after 8 weeks of the assigned diet and standardized resistance training program. Fat mass and fat-free mass were assessed by dual-energy x-ray absorptiometry and muscle area of the thigh and arm were measured using an anthropometric system. Total and free testosterone, insulin-like growth factor 1, blood glucose, insulin, adiponectin, leptin, triiodothyronine, thyroid stimulating hormone, interleukin-6, interleukin-1β, tumor necrosis factor α, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. Bench press and leg press maximal strength, resting energy expenditure, and respiratory ratio were also tested. RESULTS After 8 weeks, the 2 Way ANOVA (Time * Diet interaction) showed a decrease in fat mass in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area of the arm and thigh, and maximal strength were maintained in both groups. Testosterone and insulin-like growth factor 1 decreased significantly in TRF, with no changes in ND (p = 0.0476; p = 0.0397). Adiponectin increased (p = 0.0000) in TRF while total leptin decreased (p = 0.0001), although not when adjusted for fat mass. Triiodothyronine decreased in TRF, but no significant changes were detected in thyroid-stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, or triglycerides. Resting energy expenditure was unchanged, but a significant decrease in respiratory ratio was observed in the TRF group. CONCLUSIONS Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males.