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1.
Muscle Damage, Soreness, and Stress During Preseason Training in Collegiate Swimmers.
Rusnak, M, VanderMeulen, M, Byrd, B, Byrd, G, Rusnak, R, Martin, J, Hew-Butler, T
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. 2021;(3):237-243
Abstract
BACKGROUND In 2014, 6 collegiate swimmers were hospitalized for symptomatic exertional rhabdomyolysis. OBJECTIVE To serially monitor and assess relationships between skeletal muscle membrane disruption, upper body soreness (UBS) and lower body soreness (LBS), and stress during the first 6 weeks (timepoints) of preseason training in collegiate male and female swimmers. DESIGN Prospective observational study. SETTING College/university. PARTICIPANTS Forty swimmers. INDEPENDENT VARIABLES Upper and lower body soreness rating (0-10); testosterone (T), cortisol (C), and T/C ratio. MAIN OUTCOME MEASURES Creatine kinase (CK) and myoglobin (over time) versus independent variables. RESULTS Weekly training load consisted of ∼87% swimming, ∼5% running, and ∼8% weight training, which increased from 15.8 hours to 20.5 total training hours per week over the first 6 weeks of training. Muscle damage in collegiate swimmers was modest and peaked after the first week of training (week 2) for men (CK = 438 ± 259 U/L; P < 0.0001; r2 = 0.28; myoglobin = 47 ± 18 ng/mL; P = 0.001; r2 = 0.22) and women (CK = 446 ± 723 U/L; P < 0.01; r2 = 0.13; myoglobin = 63 ± 140 ng/mL, not significant) with high variability. Data were presented as peak mean ± SD, significant P value, and r2 from repeated-measures analysis of variance. A temporal disconnect was noted between muscle damage and UBS, which peaked at week 5 in both men (5 ± 2; P < 0.0001; r2 = 0.44) and women (6 ± 2; P < 0.0001; r2 = 0.57). The serum cortisol level decreased over time, which peaked at week 1 (baseline) in men (15 ± 6 μg/dL; P = 0.0004; r2 = 0.38) and women (19 ± 10 μg/dL; P < 0.0001; r2 = 0.49). The testosterone level remained unchanged, which promoted an anabolic hormonal environment that peaked at week 6 (increasing T/C ratio) in men (58 ± 32; P = 0.0003; r2 = 0.31) and women (4 ± 3; P = 0.04; r2 = 0.18) despite gradual increases in training and soreness. CONCLUSIONS Muscle soreness does not parallel muscle membrane disruption. A 1-week "transition" period is required for muscles to adapt to intense/novel training.
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2.
Beta alanine supplementation effects on metabolic contribution and swimming performance.
Norberto, MS, Barbieri, RA, Bertucci, DR, Gobbi, RB, Campos, EZ, Zagatto, AM, De Freitas, EC, Papoti, M
Journal of the International Society of Sports Nutrition. 2020;(1):40
Abstract
BACKGROUND Investigations of β-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of β-alanine supplementation on metabolic contribution and performance during 400-m swim. METHODS Thirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day- 1 of β-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La-]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl). RESULTS No differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89). CONCLUSIONS Thus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and β-alanine supplementation doesn't affect metabolic contribution and performance during 400-m freestyle.
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3.
The non-linear relationship between sum of 7 skinfolds and fat and lean mass in elite swimmers.
Mitchell, LJG, Morris, KS, Bolam, KA, Pritchard-Peschek, KR, Skinner, TL, Shephard, ME
Journal of sports sciences. 2020;(20):2307-2313
Abstract
Body composition can substantially impact elite swimming performance. In practice, changes in fat and lean mass of elite swimmers are estimated using body mass, sum of seven skinfolds (∑7) and lean mass index (LMI). However, LMI may be insufficiently accurate to detect small changes in body composition which could meaningfully impact swimming performance. This study developed equations which estimate dual-energy x-ray absorptiometry (DXA)-derived lean and fat mass using body mass and ∑7 data. Elite Australian swimmers (n = 44; 18 male, 26 female) completed a DXA scan and standardised body mass and ∑7 measurements. Equations to estimate DXA-derived lean and fat mass based on body mass, ∑7 and sex were developed. The relationships between ∑7, body mass and DXA-derived lean and fat mass were non-linear. Fat mass (Adjusted R2 = 0.91; standard error = 1.0 kg) and lean mass (Adjusted R2 = 0.99; standard error = 1.0 kg) equations were considered sufficiently accurate. Lean mass estimates outperformed the LMI in identifying the correct direction of change in lean mass (82% correct; LMI 71%). Using the accurate estimations produced by these equations will enhance the prescription and evaluation of programmes to optimise the body composition and subsequent performance in swimmers.
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4.
Effect of low- and high-carbohydrate diets on swimming economy: a crossover study.
Bestard, MA, Rothschild, JA, Crocker, GH
Journal of the International Society of Sports Nutrition. 2020;(1):64
Abstract
BACKGROUND Swimming economy refers to the rate of energy expenditure relative to swimming speed of movement, is inversely related to the energetic cost of swimming, and is as a key factor influencing endurance swimming performance. The objective of this study was to determine if high-carbohydrate, low-fat (HCLF) and low-carbohydrate, high-fat (LCHF) diets affect energetic cost of submaximal swimming. METHODS Eight recreational swimmers consumed two 3-day isoenergetic diets in a crossover design. Diets were tailored to individual food preferences, and macronutrient consumption was 69-16-16% and 16-67-18% carbohydrate-fat-protein for the HCLF and LCHF diets, respectively. Following each 3-day dietary intervention, participants swam in a flume at velocities associated with 50, 60, and 70% of their maximal aerobic capacity (VO2max). Expired breath was collected and analyzed while they swam which enabled calculation of the energetic cost of swimming. A paired t-test compared macronutrient distribution between HCLF and LCHF diets, while repeated-measures ANOVA determined effects of diet and exercise intensity on physiological endpoints. RESULTS Respiratory exchange ratio was significantly higher in HCLF compared to LCHF (p = 0.003), but there were no significant differences in the rate of oxygen consumption (p = 0.499) or energetic cost of swimming (p = 0.324) between diets. Heart rate did not differ between diets (p = 0.712), but oxygen pulse, a non-invasive surrogate for stroke volume, was greater following the HCLF diet (p = 0.029). CONCLUSIONS A 3-day high-carbohydrate diet increased carbohydrate utilization but did not affect swimming economy at 50-70% VO2max. As these intensities are applicable to ultramarathon swims, future studies should use higher intensities that would be more relevant to shorter duration events.
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5.
Muscle and intestinal damage in triathletes.
Tota, Ł, Piotrowska, A, Pałka, T, Morawska, M, Mikuľáková, W, Mucha, D, Żmuda-Pałka, M, Pilch, W
PloS one. 2019;(1):e0210651
Abstract
The aim of the paper was to assess indicators of muscle and intestinal damage in triathletes. The study involved 15 triathletes whose objective for the season was to start in the XTERRA POLAND 2017 event (1,500-m swimming, 36-km cycling, and 10-km mountain running). Before the 14-week preparatory period, the competitors' body composition was measured, aerobic capacity was tested (graded treadmill test) and blood samples were collected to determine markers showing the level of muscle and intestinal damage. Subsequent tests for body composition were carried out before and after the competition. Blood samples for biochemical indicators were collected the day before the competition, after the completed race, and 24 and 48 hours later. A significant decrease in body mass was observed after completing the race (-3.1±1.5%). The mean maximal oxygen uptake level among the studied athletes equalled 4.9±0.4 L·min-1, 58.8±4.5 mL·kg-1·min-1. The significant increase in concentrations of cortisol, c-reactive protein and myoglobin after the competition, significantly correlated with the significant increase in zonulin concentration (post 1h: r = 0.88, p = 0.007, r = 0,79, p = 0.001, r = 0.78, p = 0.001, and post 12h: r = 0.75, p = 0.01, r = 0.71, p = 0.011, r = 0.83, p = 0.02). No significant changes in the concentration of tumour necrosis factor alpha among the examined competitors were noted at following stages of the study. The results of our research showed that in order to monitor overload in the training of triathletes, useful markers reflecting the degree of muscle and intestinal damage include cortisol, testosterone, testosterone to cortisol ratio, c-reactive protein, myoglobin and zonulin. Changes in muscle cell damage markers strongly correlated with changes in zonulin concentration at particular stages of the study. Thus, one can expect that the concentrations of markers depicting the level of muscle cell damage after an intense and long-lasting effort will significantly influence the level of the intestinal barrier.
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6.
No Effect of Beetroot Juice Supplementation on 100-m and 200-m Swimming Performance in Moderately Trained Swimmers.
Esen, O, Nicholas, C, Morris, M, Bailey, SJ
International journal of sports physiology and performance. 2019;(6):706-710
Abstract
Purpose: Dietary nitrate supplementation has been reported to improve performance in kayaking and rowing exercise, which mandate significant recruitment of the upper-body musculature. Because the effect of dietary nitrate supplementation on swimming performance is unclear, the purpose of this study was to assess the effect of dietary nitrate supplementation on 100-m and 200-m swimming freestyle time-trial (TT) performance. Methods: In a double-blind, randomized crossover design, 10 moderately trained swimmers underwent 2 separate 3-d supplementation periods, with a daily dose of either 140 mL nitrate-rich (∼800 mg/d nitrate) or nitrate-depleted (PLA) beetroot juice (BRJ). After blood sampling on day 3, the swimmers performed both 200-m and 100-m freestyle swimming TTs, with 30 min recovery between trials. Results: Plasma nitrite concentration was greater after BRJ relative to PLA consumption (432 [203] nmol/L, 111 [56] nmol/L, respectively, P = .001). Systolic blood pressure was lowered after BRJ compared with PLA supplementation (114 [10], 120 [10] mm Hg, respectively P = .001), but time to complete the 200-m (BRJ 152.6 [14.1] s, PLA 152.5 [14.1] s) and 100-m (BRJ 69.5 [7.2] s, PLA 69.4 [7.4] s) freestyle swimming TTs was not different between BRJ and PLA (P > .05). Conclusions: Although 3 d of BRJ supplementation increased plasma nitrite concentration and lowered blood pressure, it did not improve 100-m and 200-m swimming TT performance. These results do not support an ergogenic effect of nitrate supplementation in moderately trained swimmers, at least for 100-m and 200-m freestyle swimming performance.
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7.
Swim-Specific Resistance Training: A Systematic Review.
Muniz-Pardos, B, Gomez-Bruton, A, Matute-Llorente, A, Gonzalez-Aguero, A, Gomez-Cabello, A, Gonzalo-Skok, O, Casajus, JA, Vicente-Rodriguez, G
Journal of strength and conditioning research. 2019;(10):2875-2881
Abstract
Muniz-Pardos, B, Gomez-Bruton, A, Matute-Llorente, A, Gonzalez-Aguero, A, Gomez-Cabello, A, Gonzalo-Skok, O, Casajus, JA, and Vicente-Rodriguez, G. Swim-specific resistance training: A systematic review. J Strength Cond Res 33(10): 2875-2881, 2019-The purpose of this systematic review was to determine which type of swim-specific training is most beneficial to enhance swimming performance and to determine which specific strength- or power-related tests better predict swimming performance. A search was conducted on PubMed, Cochrane Plus, and SPORTDiscus up to June 2018. Studies were distributed into 2 main categories: swim-specific dry land resistance training (SDLRT) and specific in-water swimming power training (SSWPT). From 1,844 citations, 25 met the inclusion criteria. It was determined that SSWPT was the most appropriate method to improve swimming performance, with tethered swimming protocols being the most studied and effective. In addition, SDLRT was a competent method to enhance swimming performance, and specifically, the inclusion of inertial training might evoke greater improvements in both strength/power capacities and swimming performance, than traditional resistance training. In conclusion, tether forces showed the greatest associations with swimming performance, although the efficacy of tethered swimming as an SSWPT method is yet to be confirmed. Further research should focus on the effects of SDLRT to verify the greater transfer of dry land resistance practices to swimming performance, with inertial training being potentially more beneficial than traditional resistance training.
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8.
Effect of an 11-Week In-Water Training Program With Increased Resistance on the Swimming Performance and the Basic Kinematic Characteristics of the Front Crawl Stroke.
Gourgoulis, V, Valkoumas, I, Boli, A, Aggeloussis, N, Antoniou, P
Journal of strength and conditioning research. 2019;(1):95-103
Abstract
Gourgoulis, V, Valkoumas, I, Boli, A, Aggeloussis, N, and Antoniou, P. Effect of an 11-week in-water training program with increased resistance on the swimming performance and the basic kinematic characteristics of the front crawl stroke. J Strength Cond Res 33(1): 95-103, 2019-The purpose of the study was to assess the effect of an 11-week in-water training program with increased resistance on the swimming performance and the basic kinematic characteristics of the front crawl stroke in young female swimmers. Twelve swimmers were matched in pairs according to their best performance in 50-m front crawl swimming and then were randomly assigned to an experimental or to a control group. Both groups followed exactly the same swimming training program. The only exception was that the experimental group performed a sprint training section with increased resistance pulling a water parachute, whereas the control group performed the same section without parachute. Before and after the intervention program, the best performance of both groups in 50-, 100-, and 200-m front crawl swimming were assessed. Moreover, the basic kinematic characteristics of the stroke were calculated during 50-m front crawl swimming with maximal intensity. Two-way repeated measures analyses of variance revealed significant improvement in the best performance in all swimming distances only in the experimental group (3.22-7.26%). As far as the basic kinematic characteristics of the stroke are concerned, significant modifications were found only in the mean swimming velocity in the experimental group (2.18%), whereas no significant changes were observed in the stroke length, the stroke rate, and the duration of the propulsive, and nonpropulsive phases in both groups. Thus, the findings of the current study revealed a positive effect of the in-water resistance training program in the swimming performance of young female swimmers of moderate performance level, without any negative influence in the basic kinematic characteristics of the stroke.
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9.
Physiological and Tactical On-court Demands of Water Polo.
Botonis, PG, Toubekis, AG, Platanou, TI
Journal of strength and conditioning research. 2019;(11):3188-3199
Abstract
Botonis, PG, Toubekis, AG, and Platanou, TI. Physiological and tactical on-court demands of water polo. J Strength Cond Res 33(11): 3188-3199, 2019-The purpose of the present review is to provide a quantification of the specific game's activities performed by elite water polo players and a comprehensive overview of the physiological requirements reflecting physical and tactical on-court demands in water polo. Game analysis demonstrates that various swimming movements occur throughout a match play, although approximately 50% of these are recorded in horizontal body position. The various offensive and defensive tactical actions transiently modify the playing intensity, which overall corresponds to the players' lactate threshold. Even play corresponds to 60% of total game actions, whereas the respective percentage of power-play and counterattacks may exceed 30%. The ability to perform high-intensity activities with short recovery periods is critical for water polo players. Elite water polo players present a high level of aerobic power and endurance as indicated by their maximal oxygen uptake and speed at the lactate threshold. Depending on the positional roles, outfield players are characterized as centers or peripherals. The overall physiological load seems to be similar between players at various positions, despite that centers execute more dynamic body contacts, whereas peripherals more swimming bouts. Despite limitations concerning the experimental setting, the current findings indicate that the incidence of fatigue deteriorates playing intensity and performance. Nonetheless, data from the reviewed studies should be cautiously interpreted because in some of the studies, players' substitutions were not allowed. A high conditioning level is essential for water polo, as it is associated with superior technical and tactical efficacy and lower decline of physical or technical performance within the game.
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10.
Effects of Whole Body Vibration on Tibia Strength and Structure of Competitive Adolescent Swimmers: A Randomized Controlled Trial.
Gómez-Bruton, A, González-Agüero, A, Matute-Llorente, A, Julián, C, Lozano-Berges, G, Gómez-Cabello, A, Garatachea, N, Casajús, JA, Vicente-Rodríguez, G
PM & R : the journal of injury, function, and rehabilitation. 2018;(9):889-897
Abstract
BACKGROUND Swimming has no effect on bone mass or structure. Therefore, adolescent swimmers present similar bone strength values when compared to normo-active controls, and lower values when compared to weight-bearing athletes. It thus seems necessary to try to improve bone structure and strength of adolescent swimmers through a weight-bearing intervention in order to reduce the risk of suffering osteoporosis later in life. OBJECTIVE To evaluate the effects of a 6-month whole body vibration (WBV) intervention on bone strength and structure of adolescent swimmers. DESIGN Randomized controlled trial. SETTING Research center. PARTICIPANTS A total of 51 swimmers (14.4 ± 2.0 years) participated in the study. METHODS Swimmers were randomly allocated into 2 groups: 20 swimmers (9 females) who only performed their swimming training, and 31 swimmers (15 females) who performed their swimming training and received a WBV intervention (3.6-11.6 g) 3 times per week during 6 months (VIB). OUTCOME MEASUREMENTS Peripheral quantitative computed tomography was performed in the nondominant tibia of all swimmers at 4%, 38%, and 66% of the tibia length before and after the intervention. RESULTS No differences between groups in any bone structure variable were found at pre- or postintervention. Both groups presented similar improvements in time, and no group by time interactions were found, suggesting that the WBV intervention was not intense enough to achieve positive changes in bone strength or structure. CONCLUSION WBV, at the chosen intensities and durations, had no effect on adolescent swimmers' bone strength or structure. Future studies should test other weight-bearing interventions aiming to improve bone strength and structure of adolescent swimmers. LEVEL OF EVIDENCE II.