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Repeated-sprint training in the fasted state during Ramadan: morning or evening training?
Aloui, A, Driss, T, Baklouti, H, Jaafar, H, Hammouda, O, Chamari, K, Souissi, N
The Journal of sports medicine and physical fitness. 2018;(7-8):990-997
Abstract
BACKGROUND The present study assessed the optimal moment of the day for repeated-sprint training in the fasted state during Ramadan. METHODS Thirty amateur soccer players were randomly assigned to a morning training group (MTG, training at ~08:00 a.m., N.=10), an evening training group (ETG, training around 06:00 p.m., N.=10), and a control group (N.=10). Training sessions, conducted on alternate days, consisted of 3 sets of 6×40-m shuttle sprints (2×20 m with 180° direction changes). A 20-second passive recovery and a 4-minute passive recovery were allowed between repetitions and sets, respectively. Before and after Ramadan, performance was assessed at both 08:00 a.m. and 06:00 p.m. by Countermovement Jump (CMJ), Repeated-Sprint Test (RST), and Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1). RESULTS After Ramadan, YYIRT1 performances were enhanced for both groups in the morning (7.82% and 6.29% for MTG and ETG, respectively, P<0.05), and in the evening (6.61% and 11.20%, respectively, P<0.05). Relative changes in YYIRT1 (P=0.33) and RST (-2.13% and -3.44% for MTG and ETG, respectively, P=0.49) at the specific time of training were similar for both groups. No differences were observed in CMJ performances before and after Ramadan for any group (P>0.05). CONCLUSIONS Morning or evening repeated-sprint training conducted in the fasted state during Ramadan enhanced soccer-specific endurance similarly.
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Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players: speed endurance runs versus small-sided game training.
Fransson, D, Nielsen, TS, Olsson, K, Christensson, T, Bradley, PS, Fatouros, IG, Krustrup, P, Nordsborg, NB, Mohr, M
European journal of applied physiology. 2018;(1):111-121
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Abstract
PURPOSE To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. METHODS Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21) or a small-sided game group (SSG; n = 18). Over 4 weeks, thrice weekly, SET performed 6-10 × 30-s all-out runs with 3-min recovery, while SSG completed 2 × 7-9-min small-sided games with 2-min recovery. Muscle biopsies were obtained from m. vastus lateralis pre and post intervention and were subsequently analysed for metabolic enzyme activity and muscle protein expression. Moreover, the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) was performed. RESULTS Muscle CS maximal activity increased (P < 0.05) by 18% in SET only, demonstrating larger (P < 0.05) improvement than SSG, while HAD activity increased (P < 0.05) by 24% in both groups. Na+-K+ ATPase α1 subunit protein expression increased (P < 0.05) in SET and SSG (19 and 37%, respectively), while MCT4 protein expression rose (P < 0.05) by 30 and 61% in SET and SSG, respectively. SOD2 protein expression increased (P < 0.05) by 28 and 37% in SET and SSG, respectively, while GLUT-4 protein expression increased (P < 0.05) by 40% in SSG only. Finally, SET displayed 39% greater improvement (P < 0.05) in Yo-Yo IR2 performance than SSG. CONCLUSION Speed endurance training improved muscle oxidative capacity and exercise performance more pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players.
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Time Course of Oxidative Stress, Inflammation, and Muscle Damage Markers for 5 Days After a Soccer Match: Effects of Sex and Playing Position.
Souglis, A, Bogdanis, GC, Chryssanthopoulos, C, Apostolidis, N, Geladas, ND
Journal of strength and conditioning research. 2018;(7):2045-2054
Abstract
Souglis, A, Bogdanis, GC, Chryssanthopoulos, C, Apostolidis, N, and Geladas, ND. Time course of oxidative stress, inflammation and muscle damage markers for 5 days after a soccer match: Effects of sex and playing position. J Strength Cond Res 32(7): 2045-2054, 2018-This study examined the influence of sex and playing position on the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer match. Sixty professional soccer players (30 men and 30 women) were divided into 3 groups, according to their playing position: defenders, midfielders, and attackers. Each group consisted of 10 male and 10 female players. Sixty healthy volunteers (30 men and 30 women) served as control. Blood samples were taken before and after the match and daily for 5 days after the match. Analysis of variance revealed different responses over time between sex and playing positions, as shown by the 3-way interaction, for creatine kinase (CK), protein carbonyls (PCs), catalase, fibrinogen, uric acid (UA), lactate dehydrogenase, reduced glutathione, C-reactive protein, and interleukin 6 (p < 0.01). Male players had higher values compared with women of the same playing position, for all oxidative, inflammatory, and muscle damage indices (p < 0.01). Also, in both sexes, midfielders had higher peaks in all indices compared with defenders (p < 0.05). Five days after the game CK and UA concentrations had not returned to pregame levels in any exercise group, whereas PCs were still elevated in male midfielders and attackers (p < 0.05). These results show that sex and playing position influence the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer game. This information should be taken into account by practitioners for the design of training programs after match play.
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Small-Sided Soccer in School Reduces Postprandial Lipemia in Adolescent Boys.
Smallcombe, JW, Barrett, LA, Morris, JG, Sherar, LB, Tolfrey, K
Medicine and science in sports and exercise. 2018;(11):2351-2359
Abstract
PURPOSE Although laboratory-based moderate- to high-intensity exercise reduces postprandial lipemia in adolescents, this exercise differs to the free-living physical activities in which young people typically engage. This study compared the effect of free-living afterschool soccer activity and treadmill exercise on in-school postprandial lipemia in adolescent boys. METHODS Fifteen boys (12.6 ± 0.5 yr) completed three, 2-d experimental trials. On day 1, participants rested (CON), exercised for 48 min on a treadmill at 60% V˙O2peak (TM), or played 48 min of 5-a-side soccer (SOC). On day 2, participants attended school where a capillary blood sample determined fasting triacylglycerol ([TAG]) and glucose ([glucose]) concentrations. Participants then consumed a standardized breakfast (0 h) and lunch (4.5 h), and blood samples were collected postprandially at 2.5, 5.0, and 7.0 h. RESULTS Reductions in fasting [TAG] were small-moderate after TM (-16%, 95% confidence interval [CI] = -27% to -2%, effect size [ES] = 0.46), but large after SOC (-30%, 95% CI = -40% to -20%, ES = 1.00) compared with CON; the concentration was also lower in SOC compared with TM (-18%, 95% CI = -29% to -5%, ES = 0.53). On the basis of ratios of geometric means, the area under the TAG versus time curve was 18% lower after TM (95% CI = -29% to -5%, ES = 0.51) and 25% lower after SOC (95% CI = -35% to -13%, ES = 0.76) compared with CON. By contrast, SOC and TM were not significantly different (-9%, 95% CI = -21% to 5%, ES = 0.25). CONCLUSION Compared with duration-matched inactivity (CON), after-school small-sided soccer (SOC) and treadmill exercise (TM) resulted in a similar, moderate reduction of postprandial lipemia in adolescent boys.
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Halftime Rewarm-up With Intermittent Exercise Improves the Subsequent Exercise Performance of Soccer Referees.
Yanaoka, T, Yamagami, J, Kidokoro, T, Kashiwabara, K, Miyashita, M
Journal of strength and conditioning research. 2018;(1):211-216
Abstract
Yanaoka, T, Yamagami, J, Kidokoro, T, Kashiwabara, K, and Miyashita, M. Halftime rewarm-up with intermittent exercise improves the subsequent exercise performance of soccer referees. J Strength Cond Res 32(1): 211-216, 2018-This study investigated the effect of halftime rewarm-up (RW) with intermittent exercise on the subsequent exercise performance of soccer referees, determined by the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1). Using a randomized cross-over design, 10 male referees were required to complete 2 trials. The trials consisted of the Loughborough Intermittent Shuttle Test, halftime, and Yo-Yo IR1 periods. During halftime, participants either rested on a chair (Control) or performed a halftime RW exercise for 15 minutes. The halftime RW protocol comprised 2.15 minutes of seated rest, followed by 2.15 minutes of running at 70% of the maximum heart rate (HRmax)-this cycle of recovery and running was repeated for a total of 13 minutes. The halftime RW protocol started at 1 minute after the commencement of the halftime period and concluded 1 minute before its end. The Yo-Yo IR1 performance, blood glucose, free fatty acids (FFAs), triglycerides (TGs), creatine kinase (CK), and lactate concentrations, the rating of perceived exertion, mean HR, and HRmax were analyzed. The Yo-Yo IR1 performance was higher in the halftime RW trial than in the control trial (3,095 ± 326 vs. 2,904 ± 421 m, P ≤ 0.05). The mean HR and HRmax, blood glucose, FFA, TG, CK, and lactate concentrations did not differ between the trials. The rating of perceived exertion during the halftime RW, but not after the Yo-Yo IR1 period, was higher than that in the control trial. In conclusion, this study showed that halftime RW with intermittent exercise improves the subsequent exercise performance.
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Scheduling of eccentric lower limb injury prevention exercises during the soccer micro-cycle: Which day of the week?
Lovell, R, Whalan, M, Marshall, PWM, Sampson, JA, Siegler, JC, Buchheit, M
Scandinavian journal of medicine & science in sports. 2018;(10):2216-2225
Abstract
Scheduling eccentric-based injury prevention programs (IPP) during the common 6-day micro-cycle in soccer is challenged by recovery and tapering phases. This study profiled muscle damage, neuromuscular performance, and perceptual responses to a lower limb eccentric-based IPP administered 1 (MD+1) vs 3 days (MD+3) postmatch. A total of 18 semi-professional players were monitored daily during 3 in-season 6-day micro-cycles, including weekly competitive fixtures. Capillary creatine kinase concentration (CK), posterior lower limb isometric peak force (PF), counter-movement jump (CMJ) performance, and muscle soreness were assessed 24 hours prior to match-day (baseline), and every 24 hours up to 120 hours postmatch. The IPP consisted of lunges, single stiff leg dead-lifts, single leg-squats, and Nordic hamstring exercises. Performing the IPP on MD+1 attenuated the decline in CK normally observed following match play (CON: 142%; MD+3: 166%; small differences). When IPP was delivered on MD+3, CK was higher vs CON and MD+1 trials on both MD+4 (MD+3: 260%; CON: 146%; MD+1: 151%; moderate differences) and MD+5 (MD+3: 209%; CON: 125%; MD+1: 127%; small differences). Soreness ratings were not exacerbated when the IPP was delivered on MD+1, but when prescribed on MD+3, hamstring soreness ratings remained higher on MD+4 and MD+5 (small differences). No between-trial differences were observed for PF and CMJ. Administering the IPP in the middle of the micro-cycle (MD+3) increased measures of muscle damage and soreness, which remained elevated on the day prior to the next match (MD+5). Accordingly, IPP should be scheduled early in the micro-cycle, to avoid compromising preparation for the following match.
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Nutrition-Related Considerations in Soccer: A Review.
Keen, R
American journal of orthopedics (Belle Mead, N.J.). 2018;(12)
Abstract
Soccer is the world's most popular sport. As the sport has grown, so have the physical demands and the search for ways to edge out the competition with the use of sports science and nutrition. The demands, which include intense training, ≥90 minutes matches, congested fixtures, and travel, lead to increased energy and nutrient requirements, stress on the body, and risk of impaired sleep cycles. Identifying key areas to enhance a player's performance is an ongoing effort because of individual differences. Moreover, new information is being discovered via research, and advancing technology to measure performance is always evolving. This article focuses on the core nutrition principles known to lay the foundation for a better soccer player. These principles are obvious for some; however, nutrition and hydration are often undervalued, leaving the individual player with the responsibility to eat right. This review addresses the most applicable nutrition-related recommendations for soccer players.
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Decrements in Neuromuscular Performance and Increases in Creatine Kinase Impact Training Outputs in Elite Soccer Players.
Malone, S, Mendes, B, Hughes, B, Roe, M, Devenney, S, Collins, K, Owen, A
Journal of strength and conditioning research. 2018;(5):1342-1351
Abstract
Malone, S, Mendes, B, Hughes, B, Roe, M, Devenney, S, Collins, K, and Owen, A. Decrements in neuromuscular performance and increases in creatine kinase impact training outputs in elite soccer players. J Strength Cond Res 32(5): 1342-1351, 2018-The aim of the current investigation was to understand the impact of pretraining neuromuscular performance and creatine kinase (CK) status on subsequent training performance in elite soccer players. Thirty soccer players (age: 25.3 ± 3.1 years; height: 183 ± 7 cm; mass: 72 ± 7 kg) were involved in this observational study. Each morning before training, players completed assessments for neuromuscular performance (countermovement jump; CMJ) and CK levels. Global positioning technology provided external load: total distance, high-speed distance, sprint distance, accelerations, decelerations, average metabolic power, explosive distance, and high metabolic power distance (>25.5 W·kg). Mixed-effect linear models revealed significant effects for CK and CMJ Z-score on total high-speed distance, very high-speed distance, accelerations, decelerations, explosive distance, and maximal velocity. Effects are reported with 90% confidence limits. A CK Z-score of +1 corresponded to a -5.5 ± 1.1, -3.9 ± 0.5, -4.3 ± 2.9%, -4.1 ± 2.9%, -3.1 ± 2.9%, and -4.6 ± 1.9%, reduction in total high-speed distance, very high-speed distance, accelerations, decelerations, explosive distance, and maximal velocity, respectively. Countermovement jump Z-score of -1 corresponded to a -3.5 ± 1.1, -2.9 ± 0.5, -2.1 ± 1.4, -5.3 ± 2.9%, -3.8 ± 2.9%, -1.1 ± 2.9%, and -5.6 ± 1.2% reduction in these external load measures. Magnitude-based analysis revealed that the practical size of the effect of a pretraining CMJ Z-score of -1 and CK Z-score of +1 would have on total high-speed distance, very high-speed distance, high metabolic power distance (>25.5 W·kg), accelerations, decelerations, explosive distance, and maximal velocity was likely negative. The results of this study suggest that systematic pretraining monitoring of neuromuscular and muscle stress within soccer cohorts can provide coaches with information about the training output that can be expected from individual players during a training session.
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Exercise physiology and nutritional perspectives of elite soccer refereeing.
Schenk, K, Bizzini, M, Gatterer, H
Scandinavian journal of medicine & science in sports. 2018;(3):782-793
Abstract
Referees are an integral part of soccer, and their performance is fundamental for regular match flow, irrespective of the competition level or age classes. So far, scientific interest was mainly limited to aspects of exercise physiology and match performance of soccer referees, whereas recommendations for nutrition were adopted from active professional soccer. In contrast to elite soccer players, most referees are non-professional and engaged in different occupations. Furthermore, elite referees and soccer players differ in regard to age, body composition, aerobic capacity, and training load. Thus, referees' caloric needs and recommended daily carbohydrate intake may generally be lower compared to active soccer players, with higher intakes limited to periods of increased training load and match days or for referees engaged in physical demanding occupations. With respect to fluid intake, pre-match and in-match hydration strategies generally valid in sports are recommended also for referees to avoid cognitive and physical performance loss, especially when officiating in extreme climates and altitude. In contrast to elite soccer, professional assistance concerning nutrition and training is rarely available for national elite referees of most countries. Therefore, special attention on education about adequate nutrition and fluid intake, about the dietary prevention of deficiencies (iron in female referees, vitamin D irrespective of sex and age), and basic precautions for travels abroad is warranted. In conclusion, the simple adoption of nutritional considerations from active soccer for referees may not be appropriate. Recommendations should respect gender differences, population-specific physical characteristics, and demands just as well as individual characteristics and special needs.
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Soccer helps build strong bones during growth: a systematic review and meta-analysis.
Lozano-Berges, G, Matute-Llorente, Á, González-Agüero, A, Gómez-Bruton, A, Gómez-Cabello, A, Vicente-Rodríguez, G, Casajús, JA
European journal of pediatrics. 2018;(3):295-310
Abstract
UNLABELLED The aim of this study was to analyze the effects of soccer practice on bone in male and female children and adolescents. MEDLINE, PubMed, SPORTDiscus and Web of Science databases were searched for scientific articles published up to and including October 2016. Twenty-seven studies were included in this systematic review (13 in the meta-analysis). The meta-analysis was performed by using OpenMeta[Analyst] software. It is well documented that soccer practice during childhood provides positive effects on bone mineral content (BMC) and density (BMD) compared to sedentary behaviors and other sports, such as tennis, weightlifting, or swimming. Furthermore, soccer players present higher BMC and BMD in most weight-bearing sites such as the whole body, lumbar spine, hip, and legs. Moreover, bone differences were minimized between groups during prepuberty. Therefore, the maturity status should be considered when evaluating bone. According to meta-analysis results, soccer practice was positively associated with whole-body BMD either in males (mean difference 0.061; 95%CI, 0.042-0.079) or in females (mean difference 0.063; 95%CI, 0.026-0.099). CONCLUSION Soccer may be considered a sport that positively affects bone mass during growth. Pubertal soccer players presented increased bone mass compared to controls or other athletes; however, these bone differences are minimized during the prepubertal stage. What is known: • It has been described that childhood and adolescence are important periods for bone mass and structure. • Previous studies have demonstrated that soccer participation improves bone mass in male and female children and adolescents. What is new: • The differences between soccer players and controls are more marked during puberty than prepuberty. • Weight-bearing sites such as lumbar spine, hip, femoral neck, trochanter, intertrochanteric region and both legs are particularly sensitive to soccer actions.