Ralph Beneke and Renate M. Leithäuser
Roberto Baldassarre, Cristian Ieno, Marco Bonifazi, and Maria Francesca Piacentini
Purpose: The sensation of fatigue experienced at a certain point of the race is an important factor in the regulation of pacing. The rating of perceived exertion (RPE) is considered one of the main mediators utilized by athletes to modify pacing. The aim was to analyze the relationship between pacing and RPE of elite open water swimmers during national indoor pool championships. Methods: A total of 17 elite open water swimmers (males, n = 9; females, n = 8) agreed to provide RPE every 500 m during the finals of the national championships 5-km indoor pool race. Time splits, stroke rate, and RPE were collected every 500 m. The Hazard score was calculated by multiplying the momentary RPE by the remaining fraction of the race. Athletes were placed in one of two categories: medalists or nonmedalists. For all variables, separate mixed analysis of variances (P ≤ .05) with repeated measures were used considering the splits (ie, every 500 m) as within-subjects factor and the groups (ie, medalists and nonmedalists) as between-subjects factor. Results: Average swimming speed showed a significant main effect for split for both males and females (P < .001). A significant interaction was observed between average swimming speed and groups for females (P = .032). RPE increased in both groups (P < .001) with no difference observed between groups. However, the female nonmedalists showed a disproportionate nonlinear increase in RPE (5.20 [2.31]) halfway through the event that corresponded to the point where they started significantly decreasing speed. Conclusions: The results of the present study show different pacing strategies adopted by medalists and nonmedalists despite a similar RPE.
Mohamed Romdhani, Nizar Souissi, Imen Moussa-Chamari, Yassine Chaabouni, Kacem Mahdouani, Zouheir Sahnoun, Tarak Driss, Karim Chamari, and Omar Hammouda
Purpose: To compare the effect of a 20-minute nap opportunity (N20), a moderate dose of caffeine (CAF; 5 mg·kg−1), or a moderate dose of caffeine before N20 (CAF+N) as possible countermeasures to the decreased performance and the partial sleep deprivation–induced muscle damage. Methods: Nine male, highly trained judokas were randomly assigned to either baseline normal sleep night, placebo, N20, CAF, or CAF+N. Test sessions included the running-based anaerobic sprint test, from which the maximum (P max), mean (P mean), and minimum (P min) powers were calculated. Biomarkers of muscle, hepatic, and cardiac damage and of enzymatic and nonenzymatic antioxidants were measured at rest and after the exercise. Results: N20 increased P max compared with placebo (P < .01, d = 0.75). CAF+N increased P max (P < .001, d = 1.5; d = 0.94), P min (P < .001, d = 2.79; d = 2.6), and P mean (P < .001, d = 1.93; d = 1.79) compared with placebo and CAF, respectively. Postexercise creatine kinase increased whenever caffeine was added, that is, after CAF (P < .001, d = 1.19) and CAF+N (P < .001, d = 1.36). Postexercise uric acid increased whenever participants napped, that is, after N20 (P < .001, d = 2.19) and CAF+N (P < .001, d = 2.50) and decreased after CAF (P < .001, d = 2.96). Conclusion: Napping improved repeated-sprint performance and antioxidant defense after partial sleep deprivation. Contrarily, caffeine increased muscle damage without improving performance. For sleep-deprived athletes, caffeine before a short nap opportunity would be more beneficial for repeated sprint performance than each treatment alone.
Sara Birch, Torben Bæk Hansen, Maiken Stilling, and Inger Mechlenburg
Background: Pain catastrophizing is associated with pain both before and after a total knee arthroplasty (TKA). However, it remains uncertain whether pain catastrophizing affects physical activity (PA). The aim was to examine the influence of pain catastrophizing on the PA profile, knee function, and muscle mass before and after a TKA. Methods: The authors included 58 patients with knee osteoarthritis scheduled for TKA. Twenty-nine patients had a score >22 on the Pain Catastrophizing Scale (PCS), and 29 patients had a score <11. PA was measured with a triaxial accelerometer preoperative, 3 months, and 12 months after TKA. Other outcome measures consisted of the Knee Osteoarthritis Outcome Score and dual-energy X-ray absorptiometry scans. Results: The authors found no difference in PA between patients with a better/low or a worse/high score on the PCS, and none of the groups increased their mean number of steps/day from preoperative to 12 months postoperative. Patients with better/low PCS scores had higher/better preoperative scores on the Knee Osteoarthritis Outcome Score subscales (symptoms, pain, and activity of daily living), and they walked longer in the 6-min walk test. Further, they had lower body mass index, lower percent fat mass, and higher percent muscle mass than patients with worse/high PCS scores both before and after a TKA. Conclusion: Preoperative pain catastrophizing did not influence PA before or after a TKA. Although the patients improved substantially in self-reported knee function, their PA did not increase. This may be important to consider when the clinicians are informing the patients about the expected benefits from the operation.
Isabel B. Rodrigues, Matteo Ponzano, Debra A. Butt, Joan Bartley, Zahra Bardai, Maureen C. Ashe, Philip D. Chilibeck, Lehana Thabane, John D. Wark, Jackie Stapleton, and Lora M. Giangregorio
Walking is a common activity among older adults. However, the effects of walking on health-related outcomes in people with low bone mineral density (BMD) are unknown. The authors included randomized controlled trials comparing walking to control in individuals aged ≥50 years with low BMD and at risk of fractures. The authors identified 13 randomized controlled trials: nine multicomponent interventions including walking, one that was walking only, and three Nordic walking trials. Most studies had a high risk of bias. Nordic walking may improve the Timed Up-and-Go values (1.39 s, 95% CI [1.00, 1.78], very low certainty). Multicomponent interventions including walking improved the 6-min walk test (39.37 m, 95% CI [21.83, 56.91], very low certainty) and lumbar spine BMD (0.01 g/cm2, 95% CI [0.00, 0.03], low certainty evidence). The effects on quality of life or femoral neck BMD were not significant. There were insufficient data on fractures, falls, or mortality. Nordic walking may improve physical functioning. The effects on other outcomes are less certain; one may need to combine walking with other exercises to be of benefit.
Naroa Etxebarria, Jackson Wright, Hamish Jeacocke, Cristian Mesquida, and David B. Pyne
Negative or evenly paced racing strategies often lead to more favorable performance outcomes for endurance athletes. However, casual inspection of race split times and observational studies both indicate that elite triathletes competing in Olympic-distance triathlon typically implement a positive pacing strategy during the last of the 3 disciplines, the 10-km run. To address this apparent contradiction, the authors examined data from 14 International Triathlon Union elite races over 3 consecutive years involving a total of 725 male athletes. Analyses of race results confirm that triathletes typically implement a positive running pace strategy, running the first lap of the standard 4-lap circuit substantially faster than laps 2 (∼7%), 3 (∼9%), and 4 (∼12%). Interestingly, mean running pace in lap 1 had a substantially lower correlation with 10-km run time (r = .82) than both laps 2 and 3. Overall triathlon race performance (ranking) was best associated with run performance (r = .82) compared with the swim and cycle sections. Lower variability in race pace during the 10-km run was also reflective of more successful run times. Given that overall race outcome is mainly explained by the 10-km run performance, with top run performances associated with a more evenly paced strategy, triathletes (and their coaches) should reevaluate their pacing strategy during the run section.
Kate M. Luckin-Baldwin, Claire E. Badenhorst, Ashley J. Cripps, Grant J. Landers, Robert J. Merrells, Max K. Bulsara, and Gerard F. Hoyne
Purpose: The completion of concurrent strength and endurance training can improve exercise economy in cyclists and runners; however, the efficacy of strength training (ST) implementation to improve economy in long-distance (LD) triathletes has not yet been investigated. The purpose of this study was to investigate physiological outcomes in LD triathletes when ST was completed concurrently to endurance training. Methods: A total of 25 LD triathletes were randomly assigned to either 26 weeks of concurrent endurance and ST (n = 14) or endurance training only (n = 11). The ST program progressed from moderate (8–12 repetitions, ≤75% of 1-repetition maximum, weeks 0–12) to heavy loads (1–6 repetitions, ≥85% of 1-repetition maximum, weeks 14–26). Physiological and performance indicators (cycling and running economy, swim time, blood lactate, and heart rate) were measured during a simulated triathlon (1500-m swim, 60-min cycle, and 20-min run) at weeks 0, 14, and 26. Maximal strength and anthropometric measures (skinfolds and body mass) were also collected at these points. Results: The endurance strength group significantly improved maximal strength measures at weeks 14 and 26 (P < .05), cycling economy from weeks 0 to 14 (P < .05), and running economy from weeks 14 to 26 (P < .05) with no change in body mass (P > .05). The endurance-only group did not significantly improve any economy measures. Conclusions: The addition of progressive load ST to LD triathletes’ training programs can significantly improve running and cycling economy without an increase in body mass.
Tayo Moss, Stephen Samendinger, Norbert L. Kerr, Joseph Cesario, Alan L. Smith, Deborah J. Johnson, and Deborah L. Feltz
The authors describe two research experiments exploring the influence of race on the Köhler motivation gain effect with exercise tasks. Experiment 1 tested whether partner racial dissimilarity affects individual performance. Experiment 2 created a team identity recategorization intervention to potentially counter the influence on performance observed in Experiment 1. White male participants were partnered with either a Black or Asian partner (Experiment 1) or with a Black partner utilizing team names and shirt colors as a team identity recategorization strategy (Experiment 2). Racially dissimilar dyads completed two sets of abdominal plank exercises with a Köhler conjunctive task paradigm (stronger partner; team performance outcome dependent upon the weaker-ability participant’s performance). The results of Experiment 1 suggest attenuation of the previously successful group motivation gain effect in the racially dissimilar condition. The simple recategorization strategy utilized in Experiment 2 appeared to reverse motivation losses under conjunctive-task conditions in racially dissimilar exercise dyads.
Michael W. Supples, Madison K. Rivard, Rebecca E. Cash, Kirsten Chrzan, Ashish R. Panchal, and Henderson D. McGinnis
Background: Emergency medical services (EMS) professionals demonstrate low adherence to physical activity guidelines and experience a high prevalence of obesity and incidence of injury. The authors investigate the barriers to participating in physical activity among EMS professionals. Methods: The EMS professionals employed by 15 North Carolina EMS agencies were surveyed with validated items. Multivariable logistic regression models were used to estimate the odds (odds ratio, 95% confidence interval) of not meeting physical activity guidelines for each barrier to being active, controlling for age, sex, body mass index category, race/ethnicity, certification and education level, and work hours. Results: A total of 1367 EMS professionals were invited to participate, and 359 complete responses were recorded. Half of the respondents (48.2%) met Centers for Disease Control and Prevention physical activity guidelines. According to standard body mass index categories, 55.9% were obese. There were increased odds of not meeting physical activity guidelines for the following barriers: lack of energy (5.32, 3.12–9.09), lack of willpower (4.31, 2.57–7.22), lack of time (3.55, 2.12–5.94), social influence (3.02, 1.66–5.48), and lack of resources (2.14, 1.12–4.11). The barriers of fear of injury and lack of skill were not associated with meeting physical activity guidelines. Conclusion: Half of EMS professionals did not meet physical activity guidelines, and the majority were obese. Significant associations exist between several modifiable barriers and not meeting physical activity guidelines.