Journal of Sports Science and Medicine最新文献

{"title":"Comparing the Effects of Static Stretching Alone and in Combination with Post-Activation Performance Enhancement on Squat Jump Performance at Different Knee Starting Angles.","authors":"Ming Li, Xiangwei Meng, Lihao Guan, Youngsuk Kim, Sukwon Kim","doi":"10.52082/jssm.2023.769","DOIUrl":"10.52082/jssm.2023.769","url":null,"abstract":"<p><p>We aimed to investigate the impact of isolated static stretching (4 sets of 30 seconds) and its combined form with 10 repetitive drop jumps on lower limb performance during squat jumps at different knee joint starting angles (60°, 90°, and 120°). Thirteen participants completed three randomly ordered experimental visits, each including a standardized warm-up and squat jumps at three angles, apart from the intervention or control. Information was gathered through a three-dimensional movement tracking system, electromyography system, and force platform. The electromyography data underwent wavelet analysis to compute the energy values across the four wavelet frequency bands. The average power (Pavg), peak power (Ppeak), peak ground reaction force (GRFpeak), peak center of mass velocity (Vpeak), and force-velocity relationship at peak power (SFv) were extracted from the force and velocity-time data. The results revealed no significant influence of isolated static stretching, or its combined form with drop jumps, on the energy values across the frequency bands of the gastrocnemius, biceps femoris and rectus femoris, or the Pavg or Ppeak (P > 0.05). However, at 120°, static stretching reduced the GRFpeak (P = 0.001, d = 0.86) and SFv (P < 0.001, d = 1.12), and increased the Vpeak (P = 0.001, d = 0.5). The GRFpeak, Pavg, Ppeak, and SFv increased with an increase in the joint angle (P < 0.05), whereas the Vpeak decreased (P < 0.05). These findings suggest that static stretching does not diminish power output during squat jumps at the three angles; however, it alters GRFpeak, Vpeak, and the relative contributions of force and velocity to peak power at 120°, which can be eliminated by post-activation performance enhancement. Moreover, compared to 60° and 90°, 120° was more favorable for power and peak force output.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"769-777"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690507/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technical and Tactical Actions of the World's Leading Male Table Tennis Players Between 1970 and 2021.","authors":"Jerzy Grycan, Małgorzata Kołodziej, Ziemowit Bańkosz","doi":"10.52082/jssm.2023.667","DOIUrl":"10.52082/jssm.2023.667","url":null,"abstract":"<p><p>This research aimed to determine the quantitative and qualitative structure of winning systems of the world's leading male table tennis players between 1970 and 2021. The study used the Wu game analysis method, modified by the authors, which consists of observing the game from playback, identifying the winning actions of a given player, and sorting and counting the actions, depending on the accuracy of the observation. The project identified all World Championships and Olympic Games medallists, resulting in 244 men's matches being analyzed. Three time periods were considered based on the ball used, including the 38 mm celluloid ball, 40 mm celluloid ball, and 40 mm plastic ball. Differences in the level structure, depending on the observation period, were assessed using the chi-squared test of independence. The Pearson contingency coefficient was calculated, and multiple comparisons were made. The research showed that the use of combinations changed slightly with changes in ball size and material. The first three strokes were very important in all periods. However, the importance of serves as direct scoring strokes decreased. These findings may be related to changes in the size and material used for ball production. The most winning serves in the game of the top men were side-spin forehand serves, which were also used most often during 3rd-ball-attack winning combinations. The number of actions won directly with a return, and in the return-counterattack combination, accounted for, and still constitute, about 30%, with an increasing number of backhand flicks. The research also showed an increase in the use of backhand strokes compared to forehand strokes. These findings should be considered when creating basic goals in table tennis training plans.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"667-680"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690506/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Success Factors of Rest Defense in Soccer - A Mixed-Methods Approach of Expert Interviews, Tracking Data, and Machine Learning.","authors":"Leander Forcher, Leon Forcher, Stefan Altmann, Darko Jekauc, Matthias Kempe","doi":"10.52082/jssm.2023.707","DOIUrl":"10.52082/jssm.2023.707","url":null,"abstract":"<p><p>While the tactical behavior of soccer players differs between specific phases of play (offense, defense, offensive transition, defensive transition), little is known about successful behavior of players during defensive transition (switching behavior from offense to defense). Therefore, this study aims to analyze the group tactic of rest defense (despite in ball possession, certain players safeguard quick counterattacks in case of ball loss) in defensive transition. A mixed-methods approach was used, involving both qualitative and quantitative analysis. Semi-structured expert interviews with seven professional soccer coaches were conducted to define rest defense. In the quantitative analysis, several KPIs were calculated, based on tracking and event data of 153 games of the 2020/21 German Bundesliga season, to predict the success of rest defense situations in a machine learning approach. The qualitative interviews indicated that rest defense can be defined as the positioning of the deepest defenders during ball possession to prevent an opposing counterattack after a ball loss. For instance, the rest defending players created a numerical superiority of 1.69 ± 1.00 and allowed a space control of the attacking team of 11.51 ± 9.82 [%] in the area of rest defense. The final machine learning model showed satisfactory prediction performance of the success of rest defense (Accuracy: 0.97, Precision: 0.73, f1-Score: 0.64, AUC: 0.60). Analysis of the individual KPIs revealed insights into successful behavior of players in rest defense, including controlling deep spaces and dangerous counterattackers. The study concludes regaining possession as fast as possible after a ball loss is the most important success factor in defensive transition.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"707-725"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690503/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Effects of Different Foam Roller Intervention Techniques on Knee Extensors.","authors":"Kazuki Kasahara, Andreas Konrad, Yuta Murakami, Riku Yoshida, Ewan Thomas, Masatoshi Nakamura","doi":"10.52082/jssm.2023.681","DOIUrl":"10.52082/jssm.2023.681","url":null,"abstract":"<p><p>The usefulness of Foam Roller (FR) even without a rolling stimulus (e.g., static compression with or without dynamic joint movements) has been recently demonstrated; however, the different effects of these methods remain unclear. Thus, this study aimed to compare and investigate the effects of such FR intervention methods on knee extensors. The dominant knee extensors of 20 male university students were investigated using the following four conditions: control (CON), FR with rolling (FR_rolling), FR with static compression (FR_SC), and FR with static compression + dynamic movement of the knee joint (FR_DM). FR_SC was intervened to compress the muscle belly of the knee extensors. FR_DM involved knee flexion and extension while maintaining the FR_SC condition. Knee flexion ROM, pain pressure threshold (PPT), tissue hardness, and countermovement jump (CMJ) height were outcome variables; they were compared before and immediately after the intervention. The results of this study showed that knee flexion ROM was significantly (p < 0.01) increased in FR_rolling (d = 0.38), FR_SC (d = 0.28), and FR_DM (d = 0.64). Tissue hardness was significantly (p < 0.01) decreased in FR_rolling (d = -0.55), FR_SC (d = -0.28), and FR_DM (d = -0.42). A main effect of time (<i>p</i> < 0.01) was observed in knee flexion ROM, PPT, and tissue hardness, but no change in CMJ was observed. The results of this study suggested that clinicians and athletes could choose any method they like as a warm-up routine.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"681-687"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690504/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptations to Optimized Interval Training in Soccer Players: A Comparative Analysis of Standardized Methods for Individualizing Interval Interventions.","authors":"Lu Dai, Bixia Xie","doi":"10.52082/jssm.2023.760","DOIUrl":"10.52082/jssm.2023.760","url":null,"abstract":"<p><p>Accurately prescribing supramaximal interval training facilitates targeting desired physiological adaptations. This study compared the homogeneity of adaptations in cardiorespiratory parameters to supramaximal [i.e., intensities beyond maximal aerobic speed (MAS)] interval interventions prescribed using anaerobic speed reserve (ASR), the speed attained at the end of 30-15 Intermittent Fitness Test (V_IFT), and MAS. Using repeated-measures factorial design, and during the off-season phase of the athletes' yearly training cycle, thirty national-level soccer players (age = 19 ± 1.6 years; body mass = 78.9 ± 1.6 kg; height = 179 ± 4.7 cm; Body fat = 11 ± 0.9%) were randomized to interventions consisting of 2 sets of 6, 7, 8, 7, 8, and 9-min intervals (from 1^st to 6^th week), including 15 s running at Δ%20ASR (MAS + 0.2 × ASR), 120%MAS, or 95%V_IFT followed by 15 s passive recovery. All ASR, V_IFT, and MAS programs sufficiently stimulated adaptive mechanisms, improving relative maximal oxygen uptake [V̇O_2max (<i>p</i> < 0.05; ES = 1.6, 1.2, and 1.1, respectively)], absolute V̇O_2max (<i>p</i> < 0.05; ES = 1.5, 1.1, and 0.7), ventilation [V̇_E (<i>p</i> < 0.05; ES = 1.6, 1.1, and 1.1)], O₂ pulse [V̇O₂/HR (<i>p</i> < 0.05; ES = 1.4, 1.1, and 0.6)], first and second ventilatory threshold [VT₁ (<i>p</i> < 0.05; ES = 0.7, 0.8, and 0.7) and VT₂ (<i>p</i> < 0.05; ES = 1.1, 1.1, and 0.8)], cardiac output [Q̇_max (<i>p</i> = 1.5, 1.0, and 0.7)], and stroke volume [SV_max (<i>p</i> < 0.05; ES = 0.9, 0.7, and 0.5)]. Although there was no between-group difference for the change in the abovementioned variables over time, supramaximal interval training prescribed using ASR and V_IFT resulted in a lower coefficient of variation [CV (inter-individual variability)] in physiological adaptations compared to exercise intensity determined as a proportion of MAS. Expressing the intensity of supramaximal interval programs according to the athlete's ASR and V_IFT would assist in accurately prescribing interventions and facilitate imposing mechanical and related physiological stimulus according to the athletes' physiological ceiling. Such an approach leads to identical stimulation across athletes with differing profiles and potentially facilitates more homogenized adaptations.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"760-768"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690519/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diving into Recovery. The Effects of Different Post-Competition Protocols for Enhancing Physio-Psychological Parameters in National Level Youth Swimmers.","authors":"Vincenzo Sorgente, Alejandro Lopez-Hernandez, Diego Minciacchi, José María González Ravé","doi":"10.52082/jssm.2023.739","DOIUrl":"10.52082/jssm.2023.739","url":null,"abstract":"<p><p>The purpose of this study was to elucidate whether a specific approach regarding active swimming recovery could better promote psycho-physiological recovery right after competing in a high-level swimming race. To achieve this, we recruited 50 national level youth swimmers, randomly and equally assigning them to two groups, named \"experimental\" and \"coach prescribed\". Each group performed a specific post-competition recovery protocol, consisting of different swimming paces, rest times, self-management of the exercises. We gathered data about blood lactate (BL), heart rate (HR), and rate of perceived exertion (RPE) at two different moments, the first moment right after the swimming competition (named post-competition phase), the second moment right after swimming the respective recovery protocol assigned (named post-recovery phase). A mixed MANOVA with Tukey HSD post-hoc analysis revealed no significant differences between the experimental and coach-prescribed groups in BL, HR, and RPE at the post-competition phase. At the post-recovery phase, however, the experimental group presented lower BL levels than the coach-prescribed group (2.40 ± 1.18 vs. 4.29 ± 2.07 mmol/L, p < 0.05). Finally, we found no interaction of swimming race ranking on recovery capacities. We conclude that for immediate improvement of BL in a wide range of high-level swimmers, an efficient recovery protocol should consist of several paces, high volumes, fixed and short rest times, whereas the widely popular self-managed, lower intensity approach does not seem as equally effective. Our study advances the development of novel recommendations for optimizing immediate fatigue management in competitive swimming.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 4","pages":"739-747"},"PeriodicalIF":3.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10690518/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138479338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a Home-Based Stretching Program on Bench Press Maximum Strength and Shoulder Flexibility","authors":"Konstantin Warneke, Martin Hillebrecht, Enno Claassen-Helmers, Tim Wohlann, Michael Keiner, David G. Behm","doi":"10.52082/jssm.2023.597","DOIUrl":"https://doi.org/10.52082/jssm.2023.597","url":null,"abstract":"Recent research showed significant stretch-mediated maximum strength increases when performing stretching between 5 to 120 minutes per day with the calf muscle. However, since the practical applicability of these long stretching durations was questioned and studies exploring the transferability to the upper body are scarce, the aim of this study was to investigate the possibility of using a home-based stretching program to induce significant increases in maximum strength and flexibility. Therefore, 31 recreationally active participants (intervention group: 18, control group: 13) stretched the pectoralis major for 15min/day for eight weeks, incorporating three different stretching exercises. The maximum strength was tested isometrically and dynamically in the bench press (one-repetition maximum: 1RM) as well as shoulder range of motion (ROM) performing bilateral shoulder rotation with a scaled bar. Using a two-way analysis of variance (ANOVA) with repeated measures, the results showed high magnitude Time effects (η2 = 0.388-0.582, p < 0.001) and Group*Time interaction (η2 = 0.281-0.53, p < 0.001-0.002), with increases of 7.4 ± 5.6% in 1RM and of 9.8 ± 5.0% in ROM test in the intervention group. In the isometric testing, there was a high-magnitude Time effect (η2 = 0.271, p = 0.003), however, the Group*Time interaction failed to reach significance (p = 0.75). The results are in line with previous results that showed stretch-mediated maximum strength increases in the lower extremity. Future research should address the underlying physiological mechanisms such as muscle hypertrophy, contraction conditions as well as pointing out the relevance of intensity, training frequency and stretching duration.","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135769475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological and Biochemical Adaptations to a Sport-Specific Sprint Interval Training in Male Basketball Athletes","authors":"Tao Song, Jilikeha Jilikeha, Yujie Deng","doi":"10.52082/jssm.2023.605","DOIUrl":"https://doi.org/10.52082/jssm.2023.605","url":null,"abstract":"The present study compared the effects of incorporating traditional sprint interval training (SIT) or basketball-specific SIT (SSIT) into typical off-season training of male basketball players. Adaptations to and effect size (EF) of interventions on aerobic fitness [evaluated using Yo-Yo intermittent recovery test level-1 (Yo-Yo IR1)], change of direction [T-test (TT) and Illinois agility test (IAT)], vertical jump (VJ), standing long jump (SLJ), linear speed, maximal strength [one repetition maximum test in leg press (1RMLP)], and hormonal status were examined. Male athletes (age = 25.7 ± 2.0 years; height = 188.1 ± 7.9 cm; body mass = 85.9 ± 8.0 kg) were randomly assigned to one of three groups of SIT (n = 10): three sets of 10 × 15 sec all-out intervals with 1:1 recovery between bouts and a 3-min recovery between sets; SSIT (n = 10): the same intervals as SIT + basketball-specific ball drills while running; and CON (n = 10): two sessions per week of regular basketball technical and tactical drills. SIT and SSIT resulted in significant changes compared with baseline in maximal oxygen uptake (4.9%, ES = 2.22 vs. 6%, ES = 2.57), TT (-1.8%, ES =-0.46 vs. -2.7%, ES = -1.14), IAT (-4.5%, ES = -2.01 vs. -5.4%, ES = -1.93), VJ (7.5%, ES = 0.58 vs. 12%, ES = 0.95), linear sprint time (-2.9%, ES = -0.32 vs. -4.3%, ES = -0.69), Yo-Yo IR1 (18.5%, ES = 2.19 vs. 23.7%, ES = 2.56), serum testosterone (28%, ES = 1.52 vs. 29.7%, ES = 1.59), and cortisol (-6.53%, ES = -0.37 vs. -12.06%, ES = -0.64). Incorporating SIT and SSIT into typical off-season basketball training triggers adaptive mechanisms that enhance aerobic and anaerobic performance in male basketball players. The effect size values indicate more significant effects of SSIT than SIT in most physiological and sport-specific adaptations. Such a superior effect could be attributed to the more basketball-specific movement pattern of the SSIT. Such interventions can be used by the coaches and athletes for designing the training load and for better training adaptations throughout the training seasons and competition periods.","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135768961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Effects of Selective Strength Exercise on the Peroneus Longus and Brevis.","authors":"Satoshi Arima,&nbsp;Noriaki Maeda,&nbsp;Sakura Oda,&nbsp;Hinata Esaki,&nbsp;Yuki Tamura,&nbsp;Makoto Komiya,&nbsp;Yukio Urabe","doi":"10.52082/jssm.2023.397","DOIUrl":"https://doi.org/10.52082/jssm.2023.397","url":null,"abstract":"<p><p>The peroneus muscles are muscles that mainly act in ankle eversion and can be divided into PL and PB, which have different but important roles in foot and ankle functions. Therefore, PL and PB dysfunction can lead to foot and ankle issues, making. selective strength exercise necessary. This study aimed to identify the effect of two different exercise techniques on PL and PB morphologies. Two interventions were performed on separate days: the PL intervention, in which a Thera-Band^® was placed on the ball of the foot and pushed out from the contact point, and the PB intervention, in which the Thera-Band^® was pulled from the base of the fifth metatarsal. Cross-sectional area (CSA) and thickness of the peroneus muscles at 25% (showing the PL morphology) and 75% (showing the PB morphology) proximal to the line connecting the fibular head and lateral malleolus, as well as ankle strength was measured before and immediately after the interventions and at 10, 20, and 30 min later. A repeated-measures two-way analysis of variance was conducted to identify differences in the effects of the interventions on the PL and PB. Main and interaction effects on CSA, thickness, and ankle strength, with a significant increase in CSA and thickness in the proximal 25% in the PL intervention and the distal 75% in the PB intervention immediately after implementation, were observed (p < 0.05). The transient increase in muscle volume due to edema immediately after exercise indicates the acute effect of exercise. The CSA and thickness of the proximal 25% in the PL intervention and the distal 75% in the PB intervention increased immediately after the intervention, indicating that these interventions can be used to selectively exercise the PL and PB.</p>","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 3","pages":"397-405"},"PeriodicalIF":3.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10499122/pdf/jssm-22-397.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10309549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maximal and Submaximal Intensity Isometric Knee Extensions Induce an Underestimation of Time Estimates with Both Younger And Older Adults: A Randomized Crossover Trial.","authors":"A. P. Graham, Hayley R. Gardner, H. Chaabene, S. Talpey, S. Alizadeh, David G. Behm","doi":"10.52082/jssm.2023.405","DOIUrl":"https://doi.org/10.52082/jssm.2023.405","url":null,"abstract":"Our perception of time plays a critical role in nearly all daily activities and especially in sports. There are no studies that have investigated and compared time perception during exercise in young and older adults. Thus, this study aimed to compare the effects of exercise on time perception between younger and older adult populations. Thirty-three recreationally active participants were recruited and assigned to either the younger (university students, 9 males and 10 females) or older adults (>60 years, 8 males and 6 females). All participants completed four exercise conditions over two sessions on separate days: approximately 30-seconds of knee extensors 100%, 60% and 10% of maximum voluntary isometric contraction (MVIC), and control (no contractions). Prospective time perception was estimated (at 5-, 10-, 20-, and 30-seconds) at the beginning of each session and while performing the exercise. A main effect for condition (p < 0.001, d = 1.06) with subsequent post-hoc tests indicated participants significantly underestimated (estimated time was shorter than chronological time) time in all three exercise conditions compared to the control. There were no significant age group differences. In conclusion, exercise underestimated time estimates regardless of intensity or age. This questions the postulated intensity-dependent relationship between exercise and time perception. While older adults were expected to be less accurate in their time estimates, they may have been able to adopt alternative strategies for age-related changes in their internal clock, resulting in no significant age group differences.","PeriodicalId":54765,"journal":{"name":"Journal of Sports Science and Medicine","volume":"22 3 1","pages":"406-416"},"PeriodicalIF":3.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70666407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}