Is a Four-Week Ketogenic Diet an Effective Nutritional Strategy in CrossFit-Trained Female and Male Athletes?
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ABSTRACT:
SUBMITTER: Durkalec-Michalski K
PROVIDER: S-EPMC8001376 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:The ketogenic diet is becoming a popular nutritional model among athletes. However, the relationship between its use and metabolism during exercise seems to have not been fully investigated. METHODS:The aim of the study was to assess the effects of a four-week ketogenic diet (KD) on fat and carbohydrate (CHO) utilization during an incremental cycling test (ICT) in CrossFit-trained female (n?=?11) and male (n?=?11) athletes. During the ICT (while consuming the customary diet and after the KD), oxygen uptake and carbon dioxide exhalation were registered, and CHO and fat utilization as well as energy expenditure were calculated. RESULTS:In males, the KD led to an increase in fat utilization (g·min-?1·kgFFM-?1 and % oxidation). It was particularly noticeable at exercise intensities up to 80% of VO2max. An increase in the area under the curve (AUC) was seen in males but not in females at up to ?65% VO2max of fat utilization. CONCLUSIONS:Male CrossFit-trained athletes seem to be more prone to shifts in macronutrient utilization (in favor of fat utilization) during submaximal intensity exercise under a ketogenic diet than are female athletes. TRIAL REGISTRATION:Clinical Trials Gov, NCT03665948 . Registered 11 September 2018 (retrospectively registered).
| S-EPMC6451242 | biostudies-literature
Project description:Tribulus terrestris L. (TT) ingredients have anti-inflammatory and antioxidant activities, but their effects on exercise-induced muscle damage (EIMD) in trained athletes are uncertain. The purpose of this single-blind placebo-controlled trial, in accordance with CONSORT guidelines, was to examine the effect of 6 weeks of TT supplementation on muscle metabolism, inflammation biomarkers, and oxidant status. Thirty trained male CrossFit® athletes were randomly assigned to be supplemented with 770 mg/day of TT (intervention group (IG)) or receive a placebo daily (control group (CG)) for 6 weeks. Muscle damage enzymes, inflammation biomarkers, and Total Antioxidant Status (TAS) were assessed at baseline (T1), 21 days after baseline (T2), and after 42 days (T3). Grace, a Workout of the Day, was measured in T1 and T3. Statistical significance (p < 0.05) was found between IG and CG in Lactate Dehydrogenase (LDH), C-reactive protein (CRP), and TAS levels at the end of the follow-up. Furthermore, TAS levels were significantly (p < 0.05) lower at T2 and T3 relative to baseline in the IG, also LDH and CRP increased significantly (p < 0.05) at T2 and T3 relative to baseline in the CG. No significant (p > 0.05) decreases in muscle damage or inflammation biomarkers were observed, although a slight downward trend was observed after 6 weeks for supplemented athletes. TT supplementation could attenuate the CrossFit® training program-induced oxidative stress, muscle damage, and inflammation which could be due to the natural antioxidant and anti-inflammatory properties of TT.
| S-EPMC9736311 | biostudies-literature
Project description:This interventional study examined the effect of a four-week vegan diet (VegD) during a four-week high-intensity functional training (HIFT) on performance, training results and blood biochemical indices in female (n = 12) and male (n = 8) moderate-trained CrossFit participants. The whole study group performed the maximum number of repetitions with a load of 70% one repetition-maximum (1RM) and a modified Fight Gone Bad (FGBMod) test before and after a dietary intervention (the group was divided to follow a VegD or a traditional mixed diet (MixD)) in a randomised and parallel design. Pre-exercise resting blood samples were also analysed. There was a significant improvement in the number of repetitions performed at a load corresponding to 70% of 1RM in the classic squat in the MixD group (p < 0.001), and in the classic deadlift in the VegD group (p = 0.014). Furthermore, there was a significant improvement in the results of the FGBMod performance test after a MixD. Moreover, an improvement in some exercises in the modified FGBMod test (Wall Ball after the VegD and the MixD, and rowing after the MixD) was also observed. However, differences between the MixD and the VegD groups were not clinically relevant. In conclusion, the short-term study conducted here indicated that a VegD in HIFT training positively affects strength endurance in the classic deadlift but is unlikely to be more beneficial in improving performance than a MixD.
| S-EPMC8878731 | biostudies-literature
Project description:Caffeine's ergogenic effects persist during various exercise modalities; however, information establishing its efficacy during CrossFit® protocols is limited. This study aimed to determine the effects of caffeine supplementation on CrossFit® performance. Twenty CrossFit®-trained men (age = 26.7 ± 6.2 years, experience = 3.7 ± 2.9 years) were randomized in a double-blind, crossover design. Participants completed two sessions separated by a seven-day washout period, 60 min after consuming 5 mg/kg body mass of caffeine or a placebo. In each session, participants completed as many rounds as possible in 20 min of five pull-ups, 10 push-ups, and 15 air squats. CrossFit® performance was the total number of repetitions completed in 20 min. Paired-samples t-tests were used to compare CrossFit® performance between caffeine and placebo conditions and to test for a potential learning effect between the first and second sessions. CrossFit® performance was not significantly different during the caffeine condition compared to the placebo (468.6 ± 114.7 vs. 466.7 ± 94.3 repetitions, p = 0.861). A significant learning effect was identified between the first and second sessions (452.4 ± 101 vs. 483.8 ± 106.5 repetitions, p = 0.001), with no significant effect of treatment order (p = 0.438). Caffeine's ergogenic effect were not present during the CrossFit® workout "Cindy"; however, future research should include familiarization sessions and examine other CrossFit® workouts in novice and women participants.
| S-EPMC7240695 | biostudies-literature
Project description:Milk has become a popular post-exercise recovery drink. Yet the evidence for its use in this regard comes from a limited number of investigations utilising very specific exercise protocols, and mostly with male participants. Therefore, the aim of this study was to investigate the effects of post-exercise milk consumption on recovery from a sprinting and jumping protocol in female team-sport athletes. Eighteen females participated in an independent-groups design. Upon completion of the protocol participants consumed 500 mL of milk (MILK) or 500 mL of an energy-matched carbohydrate (CHO) drink. Muscle function (peak torque, rate of force development (RFD), countermovement jump (CMJ), reactive strength index (RSI), sprint performance), muscle soreness and tiredness, symptoms of stress, serum creatine kinase (CK) and high-sensitivity C-reactive protein (hsCRP) were determined pre- and 24 h, 48 h and 72 h post-exercise. MILK had a very likely beneficial effect in attenuating losses in peak torque (180?/s) from baseline to 72 h (0.0 ± 10.0% vs. -8.7 ± 3.7%, MILK v CHO), and countermovement jump (-1.1 ± 5.2% vs. -10.4 ± 6.7%) and symptoms of stress (-13.5 ± 7.4% vs. -18.7 ± 11.0%) from baseline to 24 h. MILK had a likely beneficial effect and a possibly beneficial effect on other peak torque measures and 5 m sprint performance at other timepoints but had an unclear effect on 10 and 20 m sprint performance, RSI, muscle soreness and tiredness, CK and hsCRP. In conclusion, consumption of 500 mL milk attenuated losses in muscle function following repeated sprinting and jumping and thus may be a valuable recovery intervention for female team-sport athletes following this type of exercise.
| S-EPMC5852804 | biostudies-other
Project description:This investigation examined anthropometric, hormonal, and physiological differences between advanced (ADV; n = 8, 27.8 ± 4.2 years, 170 ± 11 cm, 79.8 ± 13.3 kg) and recreational (REC; n = 8, 33.5 ± 8.1 years, 172 ± 14 cm, 76.3 ± 19.5 kg) CrossFit (CF) trained participants in comparison to physically-active controls (CON; n = 7, 27.5 ± 6.7 years, 171 ± 14 cm, 74.5 ± 14.3 kg). ADV and REC were distinguished by their past competitive success. REC and CON were resistance-trained (>2 years) and exercised on 3-5 days·wk-1 for the past year, but CON utilized traditional resistance and cardiovascular exercise. All participants provided a fasted, resting blood sample and completed assessments of resting metabolic rate, body composition, muscle morphology, isometric mid-thigh pull strength, peak aerobic capacity, and a 3-minute maximal cycle ergometer sprint across two separate occasions (separated by 3-7 days). Blood samples were analyzed for testosterone, cortisol, and insulin-like growth factor-1. Compared to both REC and CON, one-way analysis of variance revealed ADV to possess lower body fat percentage (6.7-8.3%, p = 0.007), greater bone and non-bone lean mass (12.5-26.8%, p ≤ 0.028), muscle morphology characteristics (14.2-59.9%, p < 0.05), isometric strength characteristics (15.4-41.8%, p < 0.05), peak aerobic capacity (18.8-19.1%, p = 0.002), and 3-minute cycling performance (15.4-51.1%, p ≤ 0.023). No differences were seen between REC and CON, or between all groups for resting metabolic rate or hormone concentrations. These data suggest ADV possess several physiological advantages over REC and CON, whereas similar physiological characteristics were present in individuals who have been regularly participating in either CF or resistance and cardiovascular training for the past year.
| S-EPMC7138313 | biostudies-literature
Project description:BackgroundCrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates.PurposeTo establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and demographic categories, gym characteristics, and athletic abilities among CrossFit participants.Study designDescriptive epidemiology study.MethodsA survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia, Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further, and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using Fisher exact tests and chi-square tests.ResultsA total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P = .03). Across all exercises, injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last, the injury rate was significantly decreased with trainer involvement (P = .028).ConclusionThe injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.
| S-EPMC4555591 | biostudies-literature
Project description:The aim of this study was to determine the physiological variables that predict competition performance during a CrossFit competition. Fifteen male amateur CrossFit athletes (age, 35 ± 9 years; CrossFit experience, 40 ± 27 months) performed a series of laboratory-based tests (incremental load test for deep full squat and bench press; squat, countermovement and drop jump tests; and incremental running and Wingate tests) that were studied as potential predictors of CrossFit performance. Thereafter, they performed the five Workouts of the Day (WODs) corresponding to the CrossFit Games Open 2019, and we assessed the relationship between the laboratory-based markers and CrossFit performance with regression analyses. Overall CrossFit performance (i.e., final ranking considering the sum of all WODs, as assessed by number of repetitions, time spent in exercises or weight lifted) was significantly related to jump ability, mean and peak power output during the Wingate test, relative maximum strength for the deep full squat and the bench press, and maximum oxygen uptake (VO2max) and speed during the incremental test (all p < 0.05, r = 0.58-0.75). However, the relationship between CrossFit Performance and most laboratory markers varied depending on the analyzed WOD. Multiple linear regression analysis indicated that measures of lower-body muscle power (particularly jump ability) and VO2max explained together most of the variance (R2 = 81%, p < 0.001) in overall CrossFit performance. CrossFit performance is therefore associated with different power-, strength-, and aerobic-related markers.
| S-EPMC7277742 | biostudies-literature
Project description:ContextResearchers have shown that rehabilitation programs incorporating resistance-band and balance-board exercises are effective for improving clinical measures of function and patient-reported outcomes in individuals with chronic ankle instability (CAI). However, whether combining the 2 exercises increases improvement is unknown.ObjectiveTo determine the effectiveness of 3 rehabilitation programs on clinical measures of balance and self-reported function in adolescent patients with CAI.DesignRandomized controlled clinical trial (Trail Registration Number: ClinicalTrails.gov: NCT03447652).SettingHigh school athletic training facilities.Patients or other participantsForty-three patients with CAI (age = 16.37 ± 1.00 years, height = 171.75 ± 12.05 cm, mass = 69.38 ± 18.36 kg) were block randomized into 4 rehabilitation groups.Intervention(s)Protocols were completed 3 times per week for 4 weeks. The resistance-band group performed 3 sets of 10 repetitions of ankle plantar flexion, dorsiflexion, inversion, and eversion with a resistance band. The Biomechanical Ankle Platform System group performed 5 trials of clockwise and counterclockwise rotations, changing direction every 10 seconds during each 40-second trial. The combination group completed resistance-band and Biomechanical Ankle Platform System programs during each session. The control group did not perform any exercises.Main outcome measure(s)Variables were assessed before and after the intervention: time-in-balance test, foot-lift test, Star Excursion Balance Test, side-hop test, figure-8 hop test, Foot and Ankle Ability Measure, and Cumberland Ankle Instability Tool. We conducted 4 separate multivariate repeated-measures analyses of variance, followed by univariate analyses for any findings that were different.ResultsUsing the time-in-balance test, foot-lift test, Star Excursion Balance Test (medial, posteromedial, and posterolateral directions), and figure-8 hop test, we detected improvement for each rehabilitation group compared with the control group (P < .05). However, no intervention group was superior.ConclusionsAll 3 rehabilitation groups demonstrated improvement compared with the control group, yet the evidence was too limited to support a superior intervention. Over a 4-week period, either of the single-task interventions or the combination intervention can be used to combat the residual deficits associated with CAI in an adolescent patient population.
| S-EPMC7462179 | biostudies-literature
Project description:PurposeLow energy availability in males needs more original research to understand its health and performance consequences. The aim of the study was to induce low energy availability in previously healthy male endurance athletes by reducing energy availability by 25% for 14 consecutive days and measure any potential changes in performance, health, mental state or energy markers.MethodsEnergy availability was reduced in 12 trained, well-trained and elite endurance athletes by increasing energy expenditure and controlling energy intake. After intervention, health was assessed by blood draw, body composition was measured, energy markers by measuring resting energy expenditure, performance with three specific tests (measuring endurance, agility and explosive power) and two questionnaires were used for psychological assessment (the Three Factor Eating Questionnaire and Well-being questionnaire).ResultsReduced energy availability (22.4 ± 6.3 kcal/kg FFM/day) caused significantly lower haemoglobin values (t(12) = 2.652, p = 0.022), there was a tendency for lower iron and IGF-1 (p = 0.066 and p = 0.077, respectively). Explosive power was reduced (t(12) = 4.570, p = 0.001), lactate metabolism was altered and athletes reported poorer well-being (t(12) = 2.385, p = 0.036). Cognitive restriction was correlated with energy availability (r = 0.528, p = 0.039).ConclusionThis is the first research providing direct evidence that suboptimal energy availability negatively impacts explosive power before hormonal changes occur in male endurance athletes. It is also the first to show direct association of low energy availability and higher cognitive restriction. We also observed worse well-being and lower haemoglobin values. 25% of energy availability reduction as not enough to elicit changes in resting energy expenditure.
| S-EPMC8617370 | biostudies-literature