Anaerobic Exercise Performance Research Articles

Beyond muscles: The untapped potential of creatine

Creatine is widely used by both elite and recreational athletes as an ergogenic aid to enhance anaerobic exercise performance. Older individuals also use creatine to prevent sarcopenia and, accordingly, may have therapeutic benefits for muscle wasting diseases. Although the effect of creatine on the musculoskeletal system has been extensively studied, less attention has been paid to its potential effects on other physiological systems. Because there is a significant pool of creatine in the brain, the utility of creatine supplementation has been examined in vitro as well as in vivo in both animal models of neurological disorders and in humans. While the data are preliminary, there is evidence to suggest that individuals with certain neurological conditions may benefit from exogenous creatine supplementation if treatment protocols can be optimized. A small number of studies that have examined the impact of creatine on the immune system have shown an alteration in soluble mediator production and the expression of molecules involved in recognizing infections, specifically toll-like receptors. Future investigations evaluating the total impact of creatine supplementation are required to better understand the benefits and risks of creatine use, particularly since there is increasing evidence that creatine may have a regulatory impact on the immune system.

Effects of acute carbohydrate ingestion on anaerobic exercise performance.

BackgroundCarbohydrate (CHO) supplementation during endurance exercises has been shown to increase performance, but there is limited research with CHO supplementation during strength and conditioning exercises. Therefore, the purpose of this study was to examine the effects of various levels of CHO ingestion during acute testing sessions requiring participants to complete a strength and conditioning program designed for collegiate athletes.MethodsParticipants (n = 7) performed a series of exercises while ingesting an amino-acid electrolyte control (CON) or CON plus varying levels of CHO. The CHO beverages delivered a 2:1 (glucose: fructose) ratio at rates of 15 g/h, 30 g/h, and 60 g/h. The exercise protocol consisted of a series of short sprints, full body resistance training exercises, jumping, and shuttle running. Performance measurements were taken for sprint times, repetitions until failure [bench press, bent over row, biceps curl, overhead triceps extension], summation of total repetitions for all repetitions until failure, repetitions in a set time for two-foot line jumps, and 137-m shuttle times.ResultsA significant main effect (p < 0.05) was found in relation to CHO dose during the bench press final set repetitions to failure. Pairwise comparison with Bonferroni’s correction identified that there was significant difference (p = 0.0024) between the dosage of 15 g/h and CON during bench press. Inferential statistics identified overall RT performance with a dosage of 15 g/h compared to 60 g/h and CON was 99.2 % (very likely) and 96.7 % (very likely) to have a beneficial effect.ConclusionsThe results from this study suggest acute ingestion of CHO does not result in decrements in performance and may provide a beneficial effect to strength and conditioning performance. Strength and conditioning coaches may recommend their athletes ingest CHO during training sessions in order to maximize muscular adaptations.

The effects of pomegranate extract on anaerobic exercise performance &amp; cardiovascular responses

Background During exercise, there is an increased demand for oxygen. Increasing blood flow may provide an ergogenic effect. Dietary nitrate supplementation, such as pomegranate extract (PE), has been linked to reduced vascular resistance, enhanced vasodilation, and increased blood flow to possibly improve exercise efficiency. The purpose of this study was to evaluate the effects of acute PE supplementation on anaerobic exercise, flow mediated dilation (FMD), oxygen saturation (SP02), heart rate (HR), and blood pressure (BP).

Ischemic Preconditioning and Exercise Performance: A Systematic Review and Meta-Analysis.

Although the amount of evidence demonstrating the beneficial effects of ischemic preconditioning (IPC) on exercise performance is increasing, conclusions about its efficacy cannot yet be drawn. Therefore, the purposes of this review were to determine the effect of IPC on exercise performance and identify the effects of different IPC procedures, exercise types, and subject characteristics on exercise performance. The analysis comprised 19 relevant studies from 2000 to 2015, 15 of which were included in the meta-analyses. Effect sizes (ES) were calculated as the standardized mean difference. Overall, IPC had a small beneficial effect on exercise performance (ES = 0.43; 90% confidence interval [CI], 0.28 to 0.51). The largest ES were found for aerobic (ES = 0.51; 90% CI, 0.35 to 0.67) and anaerobic (ES = 0.23; 90% CI, -0.12 to 0.58) exercise. In contrast, an unclear effect was observed in power and sprint performance (ES = 0.16; 90% CI, -0.20 to 0.52). In conclusion, IPC can effectively enhance aerobic and anaerobic exercise performance.

Effects of Static and Dynamic Hamstring Stretching on Anaerobic Exercise Performance

Oxygen uptake (V O2) at the ventilatory threshold (Tvent) is an effective submaximal indicator of cardiorespiratory function. V O2 at Tvent is a potent indicator of the ability of an individual to withstand physical exertion, such as exercise training, activities of daily living or the physiological insult during recovery from surgery. PURPOSE: Therefore the purpose of this pilot study was to determine whether 6 weeks of RMT could be used to delay the steep increase in ventilation rate, thereby increasing Tvent and reducing the work of breathing and in sedentary adults. METHODS: 7 sedentary adults volunteered. Mean±SD for age, stature and body mass were 22.6±3.4 years, 1.72±0.11 m, and 74.4±17.8 kg, respectively. Following a pulmonary function and cycle exercise test familiarisation session participants undertook two graded cycle exercise tests, ending when the respiratory exchange ratio exceeded 1.0. Each test was separated by 6 weeks of RMT: 2 sets of 30 breaths twice daily, 7 days a week, at 50% of pre RMT maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively). TVent was calculated using the V slope method and V O2, percentage of predicted V O2 max (%pred V O2 max), power output (W) and heart rate compared pre and post RMT at TVent. PImax and PEmax were assessed pre and post RMT. Data were assessed for normality and analysed using either Dependent t-tests or Wilcoxon-Signed Rank tests. Cohen’s d (parametric) and r (non-parametric) were used to calculate small (≥0.2), moderate (≥0.5) and large (≥0.8) effect sizes. RESULTS: PImax and PEmax increased from 88±32 cmH2O to 106±29 cmH2O (p<0.01, d = 0.59) and 85±34 cmH2O to 125±56 cmH2O (p<0.05, d=0.86), respectively, pre to post RMT. V O2 at TVent increased from 2.06±0.72 l.min-1 (26.2±6.4 ml.kg-1.min-1) pre RMT to 2.22±0.66 l.min-1 (28.3±5.9 ml.kg-1.min-1) post RMT (p<0.05, r=-0.64) and %pred V O2 max increased from 78±17% pre RMT to 85±17% post RMT (p<0.05, r=-0.42). Power output at TVent increased from 95±37 W pre RMT to 113±25 W post RMT (p<0.05, d=0.57) with heart rate remaining unchanged. CONCLUSION: These preliminary data suggest a potential role for RMT in raising TVent in sedentary adults, which allowed a greater power output at Tvent without a greater cardiac response.

Acute Effects of Peristaltic Pneumatic Compression on Repeated Anaerobic Exercise Performance and Blood Lactate Clearance

Acute Effects of Peristaltic Pneumatic Compression on Repeated Anaerobic Exercise Performance and Blood Lactate Clearance

Effect of sport practice and warm-up duration on the morning–evening difference in anaerobic exercise performance and perceptual responses to it

This study was designed to assess the effect of sport practice and warm-up duration on the morning–evening differences in muscle power and fatigue during performance of anaerobic exercise and perceptual responses to it. Twenty-two male physical education students – twelve trained (TG) (21.51 ± 1.25 years, 182.17 ± 4.37 cm and 82.88 ± 11.23 kg) and ten untrained (NTG) (23.89 ± 3.17 years, 176.8 ± 2.2 cm and 82.24 ± 8.43 kg) – participated in a crossover randomized study. They were asked to perform a 30-s Wingate test during six experimental sessions (three at 08:00 and three at 18:00 h) after different active warm-up (AWU) durations (5 min, 15 min, or 20 min). The AWU consisted of pedaling at a constant pace of 60 rpm against 50% of maximal aerobic power. Rate of perceived exertion (RPE) was recorded after the AWU and again immediately after the Wingate test. Heart rate and temperature (T) were recorded during each session at rest, after AWU and immediately at the end of the Wingate test. During the Wingate test, peak power (PP), mean power (MP), and the fatigue index were recorded. While the RPE estimations were higher in NTG, no time-of-day effect was recorded in either experimental group (morning or evening). T, PP, and MP were higher in the afternoon than in the morning (p < 0.001 for PP and MP; p < 0.05 for T). Similarly, PP and MP during the Wingate test were significantly higher in the TG than in the NTG (p < 0.001). The morning–evening difference of PP and MP was affected by AWU duration; AWU15 was best in the morning for improving lower limb power for both the TG and NTG, whereas reducing this period to 5 min in the evening was appropriate for TG only.

Effects of psychological priming, video, and music on anaerobic exercise performance.

Peak performance videos accompanied by music can help athletes to optimize their pre-competition mindset and are often used. Priming techniques can be incorporated into such videos to influence athletes' motivational state. There has been limited empirical work investigating the combined effects of such stimuli on anaerobic performance. The present study examined the psychological and psychophysiological effects of video, music, and priming when used as a pre-performance intervention for an anaerobic endurance task. Psychological measures included the main axes of the circumplex model of affect and liking scores taken pre-task, and the Exercise-induced Feeling Inventory, which was administered post-task. Physiological measures comprised heart rate variability and heart rate recorded pre-task. Fifteen males (age = 26.3 ± 2.8 years) were exposed to four conditions prior to performing the Wingate Anaerobic Test: music-only, video and music, video with music and motivational primes, and a no-video/no-music control. Results indicate that the combined video, music, and primes condition was the most effective in terms of influencing participants' pre-task affect and subsequent anaerobic performance; this was followed by the music-only condition. The findings indicate the utility of such stimuli as a pre-performance technique to enhance athletes' or exercisers' psychological states.

The effect of l-citrulline and watermelon juice supplementation on anaerobic and aerobic exercise performance

Citrulline has been proposed as an ergogenic aid, leading to an interest in watermelon given its high citrulline concentration. The aim of this study was to determine the effects of a single, pre-exercise dose of l-citrulline, watermelon juice, or a placebo on the total maximum number of repetitions completed over 5 sets, time to exhaustion, maximal oxygen consumption (VO2max), anaerobic threshold, and flow-mediated vasodilation. A randomised double-blind within-participants study design was used to examine these effects among 22 participants (n = 11 males). Supplementation included either a 7.5% sucrose drink containing 6 g of l-citrulline, 710 mL of watermelon juice (~1.0 g citrulline), or a 7.5% sucrose placebo drink. Supplementation was administered 1 or 2 h before exercise testing to investigate a timing effect. There was no significant effect between the three supplements for the total number of repetitions, time to exhaustion, VO2max, anaerobic threshold, or flow-mediated vasodilation. There was also no interaction observed relative to gender or supplement timing (P > 0.05). A single dose of l-citrulline or watermelon juice as a pre-exercise supplement appears to be ineffective in improving exercise performance; however, greater doses of l-citrulline have been shown to be safe and are currently left unexamined.

Mental fatigue does not affect maximal anaerobic exercise performance.

Mental fatigue can negatively impact on submaximal endurance exercise and has been attributed to changes in perceived exertion rather than changes in physiological variables. The impact of mental fatigue on maximal anaerobic performance is, however, unclear. Therefore, the aim of the present study was to induce a state of mental fatigue to examine the effects on performance, physiological and perceptual variables from subsequent tests of power, strength and anaerobic capacity. Twelve participants took part in the single-blind, randomised, crossover design study. Mental fatigue was induced by 90 min of the computer-based Continuous Performance Task AX version. Control treatment consisted of 90 min of watching emotionally neutral documentaries. Participants consequently completed countermovement jump, isometric leg extension and a 3-min all-out cycling tests. Results of repeated measures analysis of variance and paired t tests revealed no difference in any performance or physiological variable. Rating of perceived exertion tended to be greater when mentally fatigued (mental fatigue = 19 ± 1 vs control = 18 ± 1, p = 0.096, [Formula: see text] = .232) and intrinsic motivation reduced (mental fatigue = 11 ± 4 vs control = 13 ± 6, p = 0.063, d = 0.597) in the mental fatigue condition. Near identical responses in performance and physiological parameters between mental fatigue and control conditions suggest that peripheral mechanisms primarily regulate maximal anaerobic exercise. Whereas mental fatigue can negatively impact submaximal endurance exercise, it appears that explosive power, voluntary maximal strength and anaerobic work capacity are unaffected.

Nitrate ingestion: a review of the health and physical performance effects.

This paper provides an overview of the current literature and scientific evidence surrounding inorganic nitrate (NO3−) supplementation and its potential for improving human health and physical performance. As indicative of the ever-expanding organic and natural food consumer market, athletes and health enthusiasts alike are constantly searching for ingredient-specific “super foods” and dietary supplements capable of eliciting health and performance benefits. Evidence suggests that NO3− is the viable active component within beetroot juice (BRJ) and other vegetables, responsible for health-promoting and ergogenic effects. Indeed, multiple studies support NO3− supplementation as an effective method to improve exercise performance. NO3− supplementation (either as BRJ or sodium nitrate [NaNO3−]) has also demonstrated modest benefits pertaining to cardiovascular health, such as reducing blood pressure (BP), enhancing blood flow, and elevating the driving pressure of O2 in the microcirculation to areas of hypoxia or exercising tissue. These findings are important to cardiovascular medicine/exercise physiology and suggest a possible role for NO3− supplementation: (1) as a low-cost prevention and treatment intervention for patients suffering from blood flow disorders; and (2) an effective, natural ergogenic aid for athletes. Benefits have been noted following a single bolus, as well as daily supplementation of NO3−. While results are promising, additional research is needed to determine the impact of NO3− supplementation on anaerobic exercise performance, to identify principle relationships between isolated nitrate and other ingredients found in nitrate-rich vegetables (e.g., vitamin C, polyphenols, fatty acids, thiocyanate), to explore the specific dose-response relationships needed to elicit health and ergogenic benefits, to prolong the supplementation period beyond a relatively short period (i.e., >15 days), to determine if more robust effects can be observed with longer-term treatment, and to fully examine the safety of chronic NO3− supplementation, as this continues to be a concern of some.

Effects of 28days of beta-alanine and creatine supplementation on muscle carnosine, body composition and exercise performance in recreationally active females.

BackgroundThe purpose of this study was to examine the short-term and chronic effects of β-ALA supplementation with and without creatine monohydrate on body composition, aerobic and anaerobic exercise performance, and muscle carnosine and creatine levels in college-aged recreationally active females.MethodsThirty-two females were randomized in a double-blind, placebo-controlled manner into one of four supplementation groups: β-ALA only (BA, n = 8), creatine only (CRE, n = 8), β-ALA and creatine combined (BAC, n = 9) and placebo (PLA, n = 7). Participants supplemented for four weeks included a loading phase for the creatine for week 1 of 0.3 g/kg of body weight and a maintenance phase for weeks 2–4 of 0.1 g/kg of body weight, with or without a continuous dose of β-ALA of 0.1 g/kg of body weight with doses rounded to the nearest 800 mg capsule providing an average of 6.1 ± 0.7 g/day of β-ALA. Participants reported for testing at baseline, day 7 and day 28. Testing sessions consisted of obtaining a resting muscle biopsy of the vastus lateralis, body composition measurements, performing a graded exercise test on the cycle ergometer for VO2peak with lactate threshold determination, and multiple Wingate anaerobic capacity tests.ResultsAlthough mean changes were consistent with prior studies and large effect sizes were noted, no significant differences were observed among groups in changes in muscle carnosine levels (BA 35.3 ± 45; BAC 42.5 ± 99; CRE 0.72 ± 27; PLA 13.9 ± 44%, p = 0.59). Similarly, although changes in muscle phosphagen levels after one week of supplementation were consistent with prior reports and large effect sizes were seen, no statistically significant effects were observed among groups in changes in muscle phosphagen levels and the impact of CRE supplementation appeared to diminish during the maintenance phase. Additionally, significant time × group × Wingate interactions were observed among groups for repeated sprint peak power normalized to bodyweight (p = 0.02) and rate of fatigue (p = 0.04).ConclusionsResults of the present study did not reveal any consistent additive benefits of BA and CRE supplementation in recreationally active women.

Effects of Unilateral Remote Ischemic Preconditioning on Anaerobic Exercise Performance in Recreationally Active Adults

Effects of Unilateral Remote Ischemic Preconditioning on Anaerobic Exercise Performance in Recreationally Active Adults

Fatigue Index and Fatigue Rate during an Anaerobic Performance under Hypohydrations

BackgroundSince hypohydration commonly occurs in sports, studies on anaerobic exercise performance under this condition have been extensively carried out. When describing anaerobic performance, authors usually refer to a drop in anaerobic performance as fatigue index (FI) which is conventionally calculated using peak and low power data points. Meanwhile, another possible method in explaining anaerobic fatigue is using the rate constant which is derived from the exponential decline of power output known as fatigue rate (FR). Few studies have demonstrated that there was no change in anaerobic performance under mild hypohydrations.PurposeThis study aimed to compare the kinetics of power output using FI and FR of an anaerobic performance (Wingate test) under 2, 3 and 4% state of hypohydrations.MethodThirty two collegiate cyclists (age = 22±2 years; body weight = 71.45±3.43 kg; height = 173.23±0.04 cm) were matched using their baseline anaerobic peak power (APP) then randomly divided into 4 groups of EU (euhydrated), 2H, 3H and 4H respectively.ResultsAs expected the, FI, APP, anaerobic lower power (ALP) and rating of perceived exertion (RPE) did not show significant differences between and within the groups. However, the FR in 3H (0.018±0.005s−1) and 4H (0.019±0.010s−1) were significantly lower than EU (0.033±0.012s−1). Post-test FR also showed significant reduction in 3H and 4H compared to their pre-test values (p<0.05).ConclusionDespite the lack of changes in APP and RPE, subjects in 3H and 4H showed evidence of lower reduction of power output over time. The findings support earlier reports which showed no change in anaerobic performance under mild hypohydrations. The relatively lower FR suggests higher drive in maintaining power output under hypohydrations of 3 and 4% body weight.

Role of Dietary Acid on Maximal Respiratory Exchange Ratio and Anaerobic Exercise Performance

WWEIA data were used to assess energy intake and food sources of energy in the diets of children 2-19 years of age (N1⁄418,363) over the last decade. Regression analyses were conducted to determine a p-for-trend across the NHANES data releases (2001-2002, 2003-2004, 2005-2006, 2007-2008, and 2009-2010). Covariate adjusted energy intake was 2020 9 kcal/d. Major contributors of energy (mean SE, kcal/d) in the diet across the decade were Grains (790 8); Meat, Poultry, Fish and Mixtures (321 4); Milk and Milk Products (300 4); and Sugars, Sweets and Beverages (282 4). Energy intake decreased across the five NHANES releases; there was a significant (p<0.0001) p-for-trend of -44 kcal/d per release (-42 in those 2-11 yrs and -45 in those 12-19 yrs). The largest decrease in energy was from Sugars, Sweets and Beverages (-20 kcal/d per release, p<0.0001). There were smaller decreases (kcal/d per release) in Milk and Milk Products (-7; p<0.01), Vegetables (-5; p<0.001), and Fats, Oils and Salad Dressings (-3; p<0.0001). The largest decrease (p<0.0001) in energy was in Soft Drinks (Carbonated) of -15 kcal/d per release (-9 in those 2-11 yrs and -22 in those 12-19 yrs). There were smaller decreases (p<0.01) (kcal/d per release) in Cereals, Not Cooked (-7), Milks and Milk Drinks (-6), Cakes, Cookies, Pies, Pastries (-5), White Potatoes and Starchy Vegetables (-5), Sugars and Sweets (-4), Salad Dressings (-3), and Beef (-3). Energy intake decreased in children over the decade and warrants monitoring over time to assess if this leads to better weight status for American children.

Effects of heat and different humidity levels on aerobic and anaerobic exercise performance in athletes

Previous studies suggest that the maximum oxygen uptake (VO2max) and the Wingate anaerobic test performances are decreased in hot environments, but it is unknown whether humidity changes in a hot environment further affect the results of the VO2max and Wingate anaerobic test. Nine male athletes performed VO2max and Wingate anaerobic tests under three environmental conditions: (1) 21 °C/20% relative humidity (R.H.) (control); (2) 33 °C/20% R.H. (hot–dry); and (3) 33 °C/80% R.H. (hot–wet). The participants' weight, oral temperature, and skin temperature were recorded pre-exercise and postexercise. The heart rate was monitored continuously throughout the exercise. Compared to the control condition, the hot–dry and the hot–wet conditions had lower VO2max values (control at 3779.0 ± 234.3 mL/min vs. hot–dry at 3528.2 ± 467.4 mL/min and hot–wet at 3595.9 ± 274.6 mL/min; p < 0.05). However, there was no difference in the VO2max between the hot–dry and the hot–wet conditions. A decrease in the postexercise oral-to-skin temperature gradient was strongly correlated with decreased VO2max (mL kg−1 min−1) in all conditions (r = 0.835, p < 0.001). There was no significant difference between the conditions in the peak power and anaerobic capacity during the Wingate anaerobic test. The VO2max was impaired in the hot–dry and in the hot–wet conditions, compared to the control condition; however, the different humidity levels (i.e. hot–dry vs. hot–wet) had no effect on the VO2max. The postexercise oral-to-skin temperature gradient was in line with the variance in VO2max in all three different environmental conditions. The Wingate anaerobic test performance was not affected by the hot–dry or the hot–wet conditions, compared to the control environment. These results suggest that different relative humidity conditions do not affect the VO2max or the Wingate anaerobic test performance in hot environments.

Caffeine effect on exercise performance and disease issues: an updated mini review

PurposeThe paper aims to describe the effects of caffeine intake on exercise performance as well on diabetes, cirrhosis and asthma.Design/methodology/approachThe review includes the most updated studies found in Pub‐Med all of which are in relation to caffeine and exercise performance as well as its effects on disease issues.FindingsThe majority of studies show that caffeine ingestion of about 6 mg of body weight mass may have a positive effect on endurance and anaerobic exercise performance. In addition, if it is consumed together with carbohydrates, it may also improve post‐recovery glycogen synthesis. Intake of caffeine was also found to have a positive effect on the prevention of liver cirrhosis, reducing asthma attacks and lowering the risk of type 2 diabetes.Originality/valueThe paper gives information to nutritionists, clinical dietitians and sports nutritionists on the newest data about the effects of caffeine on exercise performance and disease issues.

Effects of creatine supplementation in taekwondo practitioners.

Taekwondo (TKD) is a combat sport, which has also been proposed as a fitness program, with a strong anaerobic component. Creatine (Cr) supplementation is used to improve both anaerobic exercise performance and body composition. Therefore, Cr supplementation could be beneficial in TKD. To determine the effect of Cr supplementation (50 mg/kg body wt) on body composition, anaerobic power and blood chemistry in young male TKD practitioners. Ten male TKD practitioners (age [20 ± 2 yr], height [1.69 ± 0.06 m], and mass [67 ± 9.8 kg]) participated in a placebo-controlled, double blind, crossover study. Body composition (DEXA), anaerobic power (Wingate Test), blood lactate and blood chemistry were measured before and after supplementation. Differences between data before and after supplementation were calculated for each treatment (Cr and Placebo) and were compared using the Wilcoxon signed-rank test. Fat mass (kg) decreased after placebo (Mdn [IqR] = -0.75 [-1.44 to 0.03]) and increased following Cr intake (0.17 [-0.77 to 1.13] kg) (Z = 2.191, p < 0.028, r = 0.49). Serum triglyceride concentration (mg/mL) increased after Cr (45.00 [-7.50 to 75.00]) and decrease with placebo (-7.00 [-10.75 to 12.00]) (Z = 2.090, p < 0.037, r = 0.47). No changes were found in others parameters. Cr supplementation may increase fat mass and serum triglycerides concentration in young male TKD practitioners without improvement in anaerobic power. Cr supplementation appears to be safe, but athletes should be careful when they want to loss fat.

Effects of Glycine-Arginine-α-Ketoisocaproic Acid Supplementation in College-Age Trained Females during Multi-Bouts of Resistance Exercise

ABSTRACTGlycine-arginine-α-ketoisocaproic acid (GAKIC) has been proposed to increase anaerobic high-intensity exercise performance in male subjects. However, the effects of GAKIC ingestion in female subjects have not been studied. Therefore, the purpose of this study was to investigate the effects of GAKIC supplementation on total load volume (i.e., mass lifted) and metabolic parameters during repeated bouts of submaximal leg extensions in college-age females. Nine resistance-trained females participated in a randomized, counterbalanced, double blind study. Subjects were randomly assigned to placebo or GAKIC (10.2 g) and performed six sets of 50% of one repetition maximum leg extensions (two legs simultaneously) to failure. One week later, subjects ingested the other supplement and performed the same exercise protocol. Furthermore, blood lactic acid, blood glucose, and heart rate were also measured preexercise and 5 s after the completion of the exercise protocol (postexercise). GAKIC supplementation significantly increased leg extension total load volume (GAKIC = 1721.7 ± 479.9 kg; placebo = 1479.1 ± 396.8 kg, p < .01). Heart rate and blood lactic acid were significantly increased (p < .01 for both measures) postexercise compared to preexercise, but were not significantly different between GAKIC and placebo (p = .40 for heart rate; p = .88 for lactic acid). Blood glucose was significantly decreased (p = .03) postexercise compared to preexercise, but was not significantly different (p = .78) between GAKIC and placebo. Collectively, these findings suggest that GAKIC increased lower body resistance performance in trained college-age females; however, these findings are not necessarily generalizable.

Effects of a competitive wrestling season on body composition, endocrine markers, and anaerobic exercise performance in NCAA collegiate wrestlers

Few data exist examining the body composition, endocrine, and anaerobic exercise performance changes over a competitive wrestling season. Eighteen NCAA wrestlers were tested for endocrine markers, body composition, hydration, grip strength, and power on four occasions: prior to pre-season training (T1); after pre-season training 3 days prior to the first seasonal meet (T2); mid-season one day prior to a meet (T3); and at the end of the season 2-3 days following the last meet (T4). Body mass, percent body fat (BF %), and fat mass were significantly lower (P ≤ 0.05) at T2 and T3 compared to T1 but were not different between T1 and T4. Lean body mass was significantly reduced at T2 only. Urine specific gravity was significantly elevated at T3 compared to T1, T2, and T4. Resting cortisol concentrations did not change but resting testosterone concentrations were significantly reduced at T2, T3, and T4. Maximal grip strength was significantly reduced at T2. Vertical jump peak power was significantly reduced at T2, T3, and T4. Wingate peak power was significantly reduced at T2 and T3. However, Wingate average power and total work did not significantly change. Fatigue rate during the Wingate test was significantly improved at T2, T3, and T4 compared to T1. In conclusion, body mass, BF %, and measures of peak force and power were reduced for most of the competitive wrestling season. Competitive wrestling reduces resting total testosterone concentrations throughout the entire season.