Purpose: This study aimed to assess the effect of playing different pick-and-roll (PnR) defensive tactical options during small-sided games (SSGs) on external and internal loads in female basketball players. Methods: Twelve female basketball players (age 28 [2] y; stature 175 [6] cm; body mass 65 [7] kg; playing experience 18 [4] y) belonging to a team competing in the Lithuanian second division were recruited for this study. Across 3 experimental sessions and in a randomized order, players performed 3 SSGs sharing the same features but using 3 defensive strategies on the middle PnR action: Switch, Trap, and Drop. External load was measured using PlayerLoad (PL); the number of accelerations, decelerations, and changes of direction, classified based on their intensities as low (<2.5 m·s−2), medium (2.5–3.5 m·s−2), and high (>3.5 m·s−2); and jumps categorized as low (<40 cm) and high (≥40 cm). Internal load was measured via rating of perceived exertion (RPE). Results: Higher PL values in SSGs including Trap defense were found compared with Drop (P < .001, ES = 0.69, moderate) and Switch (P = .001, ES = 0.60, moderate). Additionally, a higher number of accelerations was registered in Trap defense compared with Drop defense (P = .027, ES = 0.99, moderate). Trap defense also led to higher RPE compared with Switch (P = .003, ES = 1.49, large) and Drop (P = .004, ES = 1.42, large) defense. Conclusions: Different defensive strategies on the middle PnR can influence the external and internal loads during SSGs, and female basketball coaches should consider the high demand of the Trap defense when designing SSGs.
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Inside the Defensive Playbook: Pick-and-Roll Tactical Adjustments Impact the External and Internal Loads During Small-Sided Games in Female Basketball Players
Abdelaziz Qarouach, Pierpaolo Sansone, Marco Pernigoni, Rasa Kreivyte, and Daniele Conte
Optimal Support for Elite Sprinters Using a Minimal, Adequate, and Accurate Approach
Jad Adrian Washif and David B. Pyne
Background: In high-performance sport, the support provided by sport scientists and other staff can be a valuable resource for coaches and athletes. Purpose: We propose and detail here the approach of “minimal, adequate, and accurate” sport-science support to ensure that programs of work and solutions are both economical and effective. Methods: Our support provision advocates for utilization of “minimal” resources (employing the least amount of time, tools, and funding) necessary to achieve the desired outcomes. We strive for “adequate” information that fulfills specific objectives without excess and with the requirement that methods and data used are “accurate” (valid and reliable). To illustrate the principles of this approach, we outline a real-world example of supporting 100-m track (athletics) sprinters preparing and competing in an international competition. The provision of performance support emphasizes an integrated approach, combining knowledge and insights from multiple sport-science disciplines. The key facets managed under this approach are (1) neuromuscular readiness, (2) wellness monitoring, (3) movement observation, (4) motivation, (5) biomechanics and performance analysis, and (6) qualitative feedback. These facets are based on the specific performance determinants and influencing factors of an event (100-m dash). Conclusions: Application of this quantitative and qualitative approach can enhance the ability to make informed decisions. Nevertheless, the approach must be planned, evaluated, and refined on a regular basis to enable effective decision making in sport-science support. The 3-element approach of “minimal, adequate, and accurate” should be codesigned and supported by the athletes, coaches, and staff to ensure successful implementation.
The Effect of a Synthetic-Grass Sport Surface on Physiology and Perception During Intermittent Exercise in Hot Conditions
Gurpreet Singh, Kyle J.M. Bennett, Hannah McGuigan, Scott G. Goddard, and Christopher J. Stevens
Purpose: The current study aimed to determine the effect of a synthetic-grass sport surface on core body temperature, skin temperature, heart rate, thermal sensation, thermal comfort, and rating of perceived exertion (RPE) during intermittent exercise in hot conditions. Methods: Using a randomized crossover design, 13 trained/developmental team-sport athletes completed two 50-minute standardized intermittent running protocols on a synthetic and a natural-grass surface, on separate days (control-condition air temperature 32.6 °C [1.3 °C], relative humidity 43.2% [5.3%]). Results: Final skin temperature was significantly higher on synthetic compared with natural grass at the calf (40.1 °C [2.5 °C] vs 33.4 °C [0.6 °C]; P < .001), shoulder (36.6 °C [1.7 °C] vs 33.7 °C [0.7 °C]; P < .001), and chest (33.2 °C [1.1 °C] vs 31.8 °C [1.2 °C]; P = .02). Thermal sensation (median: 2.3; interquartile range [0.5] vs 2.2 [0.5], P = .03) and sweat rate (1.5 [0.4] L·h−1 vs 1.2 [0.3] L·h−1; P = .02) were also significantly higher on synthetic grass. While final core body temperature was significantly higher on the natural than synthetic grass (38.4 °C [0.3 °C] vs 38.2 °C [0.4 °C]), there were no significant differences in delta core temperature, as well as heart rate, thermal comfort, or RPE. Conclusions: Higher skin temperatures, thermal sensation, and sweat rates suggest that exercising on synthetic grass in hot conditions may increase some markers of heat strain during exercise. However, delta core body temperature, heart rate, thermal comfort, and RPE remained unaffected.
The Efficacy of Ischemic Preconditioning on Handgrip Strength and Strength Endurance in Para-Athletes With Spinal-Cord Injury: A Pilot Study
Lexi Kasofsky, Rebecca Cross, Dallin Tavoian, and Jason Siegler
Purpose: This pilot study investigated the functional outcomes after ischemic preconditioning (IPC) in high-level para-athletes with spinal-cord injury. Methods: Nine athletes completed 2 handgrip exercise trials (an isometric hold to failure at 60% maximal voluntary contraction [ISO] and a progressive, intermittent handgrip to failure [INT]), preceded by either IPC (220 mm Hg) or sham (20 mm Hg) for six 5-minute periods, in a repeated-measures, crossover design. Results: Although small performance improvements in time to task failure were observed in the ISO (∼5%) and INT (∼8%) IPC conditions, which are similar to those reported elsewhere, no statistical influence was observed (ISO–IPC, 74.2 [32.6] s; SHAM, 70.7 [27.2] s; P = .73; INT–IPC, 426.0 [80.1] s; SHAM, 392.2 [42.5] s; P = .35). Fatigue was evident in the forearm muscle force (maximal voluntary contraction) ISO (mean decline of 178.1 [76.0] N [95% CI, −10.4 to 366.7 N]; P < .05) and INT (mean decline of 182.2 [72.5] N [95% CI, 34.5–329.8 N]; P < .05) trials but not different between treatments (P > .95). Conclusions: Although small performance improvements in time to task failure were observed, the findings of the present data set suggest that acute bouts of IPC do not meaningfully influence fatigue during handgrip exercise in para-athletes with spinal-cord injury.
Training-Load Management Ambiguities and Weak Logic: Creating Potential Consequences in Sport Training and Performance
Stephen West, Ian Shrier, Franco M. Impellizzeri, Jo Clubb, Patrick Ward, and Garrett Bullock
Background: The optimization of athlete training load is not a new concept; however in recent years, the concept of “load management” is one of the most widely studied and divisive topics in sports science and medicine. Purpose: Discuss the challenges faced by sports when utilizing training load monitoring and management, with a specific focus on the use of data to inform load management guidelines and policies/mandates, their consequences, and how we move this field forward. Challenges: While guidelines can theoretically help protect athletes, overzealous and overcautious guidelines may restrict an athlete’s preparedness, negatively influence performance, and increase injury risk. Poor methods, wrong interpretation of study findings, and faulty logic do not allow for systematic scientific evaluations to inform guidelines. Practical Solutions: Guidelines and mandates should be developed through a systematic research process with stronger research designs and clear research questions. Collaborating with statistical and epidemiological experts is essential. Implementing open science principles and sharing all sports training load data increase transparency and allow for more rapid and valid advancements in knowledge. Practitioners should incorporate multiple data streams and consider individual athlete responses, rather than applying broad guidelines based on average data. Conclusion: Many current training load guidelines and mandates in sports come from good intentions; however, they are arbitrary without sound knowledge of the underlying scientific principles or methods. Common sense guidelines are helpful when there is sparse literature, but they should be careful to avoid arbitrarily choosing findings from weak research. Without precise scientific inquiries, implementing training load interventions or guidelines can have negative implications.
Validating the Use of Continuous Glucose Monitors With Nondiabetic Recreational Runners
Lesley J. Mason, Timothy Hartwig, and David Greene
Purpose: Continuous glucose monitors (CGMs) are becoming increasingly popular among endurance athletes despite unconfirmed accuracy. We assessed the concurrent validity of the FreeStyle Libre 2 worn on 2 different sites at rest, during steady-state running, and postprandial. Methods: Thirteen nondiabetic, well-trained recreational runners (age = 40 [8] y, maximal aerobic oxygen consumption = 46.1 [6.4] mL·kg–1·min–1) wore a CGM on the upper arm and chest while treadmill running for 30, 60, and 90 minutes at intensities corresponding to 50%, 60%, and 70% of maximal aerobic oxygen consumption, respectively. Glucose was measured by manually scanning CGMs and obtaining a finger-prick capillary blood glucose sample. Mean absolute relative difference, time in range, and continuous glucose Clarke error grid analysis were used to compare paired CGM and blood glucose readings. Results: Across all intensities of steady-state running, we found a mean absolute relative difference of 13.8 (10.9) for the arm and 11.4 (9.0) for the chest. The coefficient of variation exceeded 70%. Approximately 47% of arm and 50% of chest paired glucose measurements had an absolute difference ≤10%. Continuous glucose Clarke error grid analysis indicated 99.8% (arm) and 99.6% (chest) CGM data fell in clinically acceptable zones A and B. Time-in-range analysis showed reduced accuracy at lower glucose levels. However, CGMs accurately detected trends in mean glucose readings over time. Conclusions: CGMs are not valid for point glucose monitoring but appear to be valid for monitoring glucose trends during steady-state exercise. Accuracy is similar for arm and chest. Further research is needed to determine whether CGMs can detect important events such as hypoglycemia during exercise.
Antidoping 2.0: Is Adding Power-Output Data to the Antidoping Pool the Next Step? Experts’ Viewpoint
Sebastian Sitko, Pedro Valenzuela, Nathan Townsend, Marco Pinotti, Mikel Zabala, Xabier Artetxe, Gabriele Gallo, Manuel Mateo-March, Dajo Sanders, Frédéric Grappe, David C. Clarke, Teun van Erp, and Aitor Viribay
Background: Efforts are needed to improve antidoping procedures. The widespread use of power meters among cyclists could help in this regard. However, controversy exists on whether performance monitoring through power-output data could be of help for antidoping purposes. Purpose: The objective of the present study was to provide insight into the feasibility and utility of implementing power-based performance monitoring in elite cycling. An expert panel of 15 applied sport scientists and professional cycling coaches were asked for their opinions and perspectives on incorporating power data into the antidoping risk-assessment process. Results: Two different viewpoints were identified from the responses provided by the experts. Some believed that power monitoring could be implemented as an antidoping tool, provided that several surmountable challenges are first addressed. These authors provided suggestions related to the potential practical implementation of such measures. Others, on the contrary, believed that power meters lack sufficient reliability and suggest that the professional cycling world presents conflicts of interest that make this intervention impossible to implement nowadays. Conclusions: The debate around the utility of power-meter data in the antidoping fight has been ongoing for more than a decade. According to the opinions provided by the experts’ panel, there is still no consensus on the real utility and practical implementation of this intervention.
Effects of Foot-Strike Pattern on Neuromuscular Function During a Prolonged Graded Run
Gianluca Vernillo, Matheus Aguiar, Aldo Savoldelli, Aaron Martinez, Marlene Giandolini, Nicolas Horvais, W. Brent Edwards, and Guillaume Y. Millet
Purpose: To study whether, during typical-level running, non-rear-foot strikers (non-RFS) or rear-foot strikers (RFS) presented a similar or different extent of neuromuscular fatigue after a prolonged graded run. Methods: Sixteen experienced male trail runners (8 non-RFS and 8 RFS) performed a 2.5-hour treadmill graded running exercise. Before and after exercise, neuromuscular tests were performed to assess neuromuscular fatigue of the plantar flexors. Biomechanical gait parameters were acquired with an instrumented treadmill, and electromyographic activity of the lower-limb muscles was collected as an index of muscle activation. Results: There were no significant time × foot strike interactions for neuromuscular (all P ≥ .742), muscle activation (all P ≥ .157), or biomechanical (all P ≥ .096) variables. Conclusions: A dominant level running foot-strike pattern did not directly affect the extent of neuromuscular fatigue during a prolonged graded run. This suggests that no ideal running foot-strike pattern exists to minimize neuromuscular fatigue during prolonged-duration races wherein cumulative uphill and downhill segments are high, such as in trail running.
Self-Paced Field Running Test in Monitoring Fatigue and Training Adaptations in Recreational Runners
Olli-Pekka Nuuttila, Arja Uusitalo, Veli-Pekka Kokkonen, and Heikki Kyröläinen
Purpose: To examine the reproducibility and sensitivity of a self-paced field running test (SFT) in monitoring positive and negative changes in endurance performance. Methods: A total of 27 (11 women) recreational runners participated in a 6-week training intervention. The intervention was divided into a 3-week baseline period, a 2-week overload period, and a 1-week recovery period. An incremental treadmill test was performed before the baseline period and a 3000-m running test before and after all periods (T1–T4). In addition, the participants performed once a week an SFT (SFT1–6), which consisted of submaximal (6 + 6 + 3-min test at perceived exertion of 9/20, 13/20, and 17/20) and maximal sections (6 × 3-min intervals at maximum sustainable effort). The associations between the incremental treadmill test and the SFT1 performance were examined with the Pearson correlation, and the intraclass correlation was analyzed for the parameters of SFT1 to SFT3 sessions during the baseline period. The repeated-measures correlation was calculated for the 3000-m speed at T1 to T4 and the corresponding speeds at SFT. Results: Significant associations (r = .68–.93; P < .001) were found between the speeds of the SFT and the peak and lactate threshold speeds of the incremental treadmill test. Intraclass correlations varied between .77 and .96, being the highest for the average speed of 6 × 3-minute intervals. Repeated-measures correlation was significant (P < .05) for the 9/20 (r = .24), 13/20 (r = .24), and 6 × 3-minute intervals (r = .29). Conclusions: The SFT seemed a reproducible method to estimate endurance performance in recreational runners. The sensitivity to track short-term and small-magnitude changes in performance seems more limited and might require more standardized conditions.
The Effect of a Newly Developed Hand Rim on Mobility Performance and Propulsion Technique in Wheelchair Tennis Players
Thomas Rietveld, Rowie J.F. Janssen, Lucas H.V. van der Woude, Riemer J.K. Vegter, and Sonja de Groot
Purpose: To investigate the effect of a newly developed hand rim in wheelchair tennis players from a lab and field perspective. Methods: Nine wheelchair tennis players performed a set of field and lab tests with the new rim (NR) and regular rim on the racket side. Each player had a 60- to 120-minute regular training session with the NR. Three wheelchair tennis field tests (20-m sprint, Illinois, spider) were completed on a hard court using inertial measurement units. The inertial measurement units enabled analysis of linear/rotational velocity and acceleration. In the lab, two 4-minute submaximal tests (at 1.5 and 2 m/s, 0.2 W/kg), followed directly by a 5-second sprint, on a wheelchair ergometer were completed. Force and velocity were measured continuously throughout all tests. Mixed linear models investigated the effect between the 2 hand rims. Results: During the spider test, mean rotational velocity to the racket side (−2%, P = .005) was lower in the NR, and end times were similar between hand-rim conditions. No differences were observed in the 20-m sprint and Illinois field tests. In the lab, contact angle (+6%, P = .04), cycle time (+12%, P = .007), and work per push (+13%, P = .005) were higher in the NR during submaximal propulsion. Work per push (+13%, P = .007), peak velocity (+3%, P < .001), and distance covered (+4%, P = .02) were higher with the NR during the 5-second sprint test. Conclusions: The NR seems slightly favorable compared with the regular rim during performance testing on a wheelchair ergometer in wheelchair tennis players. A longer practice time might show more insights between the hand-rim types.
