"Impact of aging on maximal oxygen uptake adjusted for lower limb lean mass, total body mass, and absolute values in runners".

Performance in endurance sports decreases with aging, which has been primarily attributed to cardiovascular and musculoskeletal aging; however, there is still no clear information on the factors that are most affected by aging. The aim of this study was to compare two groups of runners (< 50 and > 50 years of age) according to their absolute, weight-adjusted maximal oxygen uptake (V̇O2max), lower limb lean mass-adjusted V̇O2max, ventilatory threshold, and respiratory compensation point (RCP). A total of 78 male recreational long-distance runners were divided into Group 1 (38.12 ± 6.87 years) and Group 2 (57.55 ± 6.14 years). Participants were evaluated for body composition, V̇O2max, VT, and RCP. Group 1 showed higher absolute and body mass-adjusted V̇O2max (4.60 ± 0.57 l·min-1 and 61.95 ± 8.25 ml·kg-1·min-1, respectively) than Group 2 (3.77 ± 0.56 l·min-1 and 51.50 ± 10.22 ml·kg-1·min-1, respectively), indicating a significant difference (p < 0.001, d = - 1.46 and p < 0.001, d = - 1.16). Correspondingly, Group 1 showed a significantly higher lower limb lean mass-adjusted V̇O2max (251.72 ± 29.60 ml·kgLM-1·min-1) than Group 2 (226.36 ± 43.94 ml·kgLM-1·min-1) (p = 0.008, d = - 0.71). VT (%V̇O2max) (p = 0.19, d = 0.19) and RCP (%V̇O2max) (p = 0.24, d = 0.22) did not differ between the groups. These findings suggest that both variables that are limited by central or peripheral conditions are negatively affected by aging, but the magnitude of the effect is higher in variables limited by central conditions. These results contribute to our understanding of how aging affects master runners.

Running economy in long-distance runners is positively affected by running experience and negatively by aging.

INTRODUCTION: The maximum oxygen uptake (V˙O2max), the maximum rate of oxygen that can be sustained before the onset of blood lactate accumulation, and the metabolic cost of locomotion are the main physiological factors associated with long-distance running performance. The latter is known as the running economy. Generally, runners reach peak performance in long races between 25 and 30 years of age, with a progressive decline occurring thereafter. However, it is not known whether the running economy is affected or how it is affected by aging. AIM: To investigate the effect of age and years of running experience on the running economy of amateur long-distance runners aged 20-80 years. METHODS: Sixty-nine recreational long-distance runners, divided into five age groups according to decade of life, participated in this study: Group 1 (n= 9) 27.2 ± 1.3 years, Group 2 (n= 18) 35.9 ± 2.2 years, Group 3 (n= 17) 43.4 ± 2.8 years, Group 4 (n= 17) 53.0 ± 2.3 years, and Group 5 (n= 8) 65.5 ± 2.9 years. For running economy assessment, oxygen cost (OC) and energy cost (EC) were measured. Furthermore, the participants were interviewed on their running experience. RESULTS: For EC, the two independent variables composing the regression model were age (ß = 0.703, t= 5.443, p < 0.001) and running experience (ß = -0.230, t = -1.785, p= 0.07), and 34% of the energy cost variation can be explained by these two factors. EC and OC were compared among the groups. There were no significant differences between Groups 1 and 2 (p= 0.999), Groups 1 and 3 (p= 1.000), and Groups 1 and 4 (p= 0.528). However, Group 5 had a significantly higher energy cost than Group 1 (p < 0.001), Group 2 (p < 0.001), Group 3 (p < 0.001) and Group 4 (p < 0.001). CONCLUSION: The number of years of running experience has a positive effect on running economy, but it is insufficient to overcome the negative effect of the aging process. Furthermore, running economy was significantly worse in participants aged ≥60 years compared with that in younger athletes.

CrossFit and the Epidemiology of Musculoskeletal Injuries: A Prospective 12-Week Cohort Study.

BACKGROUND: Despite the increasing international popularity of CrossFit, there is a paucity of scientific evidence on the risk of CrossFit-related musculoskeletal injuries (CRMIs). PURPOSE: To investigate the incidence (cumulative incidence proportion [IP] and incidence density [ID]) of CRMIs and the association of CRMIs with personal and training characteristics. STUDY DESIGN: Descriptive epidemiology study. METHODS: A prospective, 12-week descriptive epidemiology cohort study was conducted in a convenience sample of CrossFit facilities in a single Brazilian city. Printed baseline questionnaires were distributed to 13 CrossFit boxes. All participants who filled out the questionnaire and consented to participate in the study were invited to respond to an online follow-up questionnaire every 2 weeks to collect data on CrossFit training characteristics and CRMIs. A CRMI was defined as any self-reported musculoskeletal injury or pain that prevented an athlete from exercising for at least 1 day. The IP was defined as the number of new cases divided by the entire population at risk, while the ID was defined as new events divided by the total person-time exposure in hours. Logistic mixed models were developed to investigate the association of CRMIs with personal and training characteristics. RESULTS: A total of 515 CrossFit participants filled out the baseline questionnaire and provided informed consent, and 406 (78.8%) completed at least 1 follow-up measure. There were 133 participants who reported at least 1 CRMI during the study, and a total of 247 unique and new CRMIs were reported over a total estimated person-time exposure to CrossFit of 13,041 hours. The IP was 32.8% (95% CI, 28.4%-37.5%). The ID was 18.9 (95% CI, 16.6-21.3) per 1000 hours of CrossFit exposure. The shoulders (19.0%; n = 47) and lumbar spine (15.0%; n = 37) were most affected. Muscle injuries (45.3%; n = 112) and joint pain (24.7%; n = 61) were the most common CRMI types reported. Switching between prescribed and scaled down training loads (odds ratio [OR], 3.5 [95% CI, 1.7-7.3]) and previous injuries (OR, 3.2 [95% CI, 1.4-7.7]) were risk factors for a CRMI, while CrossFit experience was identified as a protective factor (OR, 0.7 [95% CI, 0.5-1.0]). CONCLUSION: In this 12-week prospective study, the ID was 18.9 CRMIs per 1000 hours of exposure; switching between training loads and previous injuries was associated with 3.5- and 3.2-fold higher odds, respectively, of sustaining CRMIs.

Photobiomodulation therapy and NMES improve muscle strength and jumping performance in young volleyball athletes: a randomized controlled trial study in Brazil.

The purpose of this study was to investigate the effectiveness of adding photobiomodulation therapy and neuromuscular electrical stimulation (NMES) to volleyball athletes' training, focusing on muscle strength and jumping skills. Thirty-six athletes were randomly placed into three groups: control, photobiomodulation therapy, and NMES. The athletes trained to improve their muscle strength and jumping skills. The athletes in the photobiomodulation therapy group were submitted to photobiomodulation therapy (850 nm, continuous, energy density 0.8 J/cm2, radiant energy per point 6 J, total radiant energy 36 J) before undergoing strength and plyometric training. The NMES group additionally underwent NMES-based quadriceps femoris muscle strength training (base frequency 1 kHz, frequency modulation 70 Hz, intensity maximum tolerable). The variables analyzed were muscle strength, jumping ability, global impression, and jump frequency; they were measured at baseline and during follow-ups at 6 and 8 weeks. The statistical analysis was conducted on an intention-to-treat basis. The between-group differences and their respective 95% CIs were calculated using linear mixed models by using group, time, and group-versus-time interaction terms. Dominant lower limb strength improved the most in the NMES group compared to the control group (mean difference = 1.4, 95% CI = .5 to 2.4). Non-dominant lower limb strength increased in both the photobiomodulation therapy group (mean difference = 1.1, 95% CI = .3 to 2) and the NMES group (mean difference = 1.9, 95% CI = 1.1 to 2.8) compared to the control group, but the NMES group improved more than the photobiomodulation therapy group (mean difference = 0.8, 95% CI = 0.1 to 1.7). The NMES group had the greatest improvement in global perceived effect scale compared to the control group (mean difference = 1.1, 95% CI = 1 to 2.2). Dominant lower limb strength improved in the NMES group compared to the control group. Non-dominant lower limb strength increased in both the photobiomodulation therapy group and the NMES group compared to the control group, but the NMES group improved significantly more than the photobiomodulation therapy group; the NMES group also improved in the global perceived effect scale compared to the control group. This study found that, for volleyball athletes, photobiomodulation therapy and NMES both promoted benefits in terms of muscle-strength gain. In addition, these benefits were maintained for 2 weeks even after training was interrupted. Dominant lower limb strength improved in the NMES group compared to the control group. Non-dominant lower limb strength increased in both the photobiomodulation therapy group and the NMES group compared to the control group, but the NMES group improved significantly more than the photobiomodulation therapy group; the NMES group also improved in global impression of jumps compared to the control group.

ANODAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) INCREASES ISOMETRIC STRENGTH OF SHOULDER ROTATORS MUSCLES IN HANDBALL PLAYERS.

BACKGROUND: Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. HYPOTHESIS/PURPOSE: The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. STUDY DESIGN: Randomized, double-blind, placebo-controlled, crossover study. METHODS: Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm2) with a one-week interval between stimulations. RESULTS: Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. CONCLUSIONS: The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. LEVEL OF EVIDENCE: 2.

Translation, Cross-cultural Adaptation, and Clinimetric Testing of Instruments Used to Assess Patients With Ankle Sprain in the Brazilian Population.

Study Design Clinical measurement study. Background Ankle sprain is a common condition. Therefore, translated, culturally adapted, and clinimetrically tested instruments for measuring the ankle are needed. Objectives To translate and cross-culturally adapt the Sports Athlete Foot and Ankle Score (SAFAS) and the global rating of change (GROC) into Brazilian Portuguese. This study also aimed to test the measurement properties of the SAFAS, the GROC, and the existing Brazilian-Portuguese versions of the numeric pain-rating scale (NPRS) and the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS) in a group with ankle sprain. Methods The SAFAS and GROC instruments were cross-culturally adapted into Brazilian Portuguese and pretested in this population (n = 18). The measurement properties of the SAFAS, GROC, NPRS, and AOFAS (internal consistency, ceiling and floor effects, construct validity, reproducibility, and responsiveness) were tested in a test-retest design in patients with ankle sprain at baseline (n = 63) and at follow-up periods of 48 to 72 hours (n = 53) and 4 weeks (n = 43) after baseline. Results The SAFAS, GROC, NPRS, and AOFAS yielded considerable internal consistency (Cronbach alpha ranging from .76 to .97), moderate reliability (intraclass correlation coefficient model 2,1 ranging from 0.59 to 0.80), and dubious agreement (percentage of the standard error of measurement ranging from 13% to 22.43%). The highest correlations on construct validity were observed among the 4 SAFAS subscales (Pearson r = 0.75 to 0.86, P<.01), but statistically significant values appeared in the intercorrelation of instruments. There were no observed floor or ceiling effects in any of the instruments. All of their scores of change showed moderate correlation with the GROC (r = -0.48 to 0.30, P<.05) and could be classified as responsive. Conclusion The Brazilian-Portuguese versions of the SAFAS, GROC, NPRS, and AOFAS had acceptable measurement properties in high-performing athletes. J Orthop Sports Phys Ther 2016;46(12):1042-1050. Epub 8 Nov 2016. doi:10.2519/jospt.2016.6218.

Translation, cross-cultural adaptation, and clinimetric testing of instruments used to assess patients with patellofemoral pain syndrome in the Brazilian population.

STUDY DESIGN: Clinical measurement study. OBJECTIVES: To cross-culturally adapt the Anterior Knee Pain Scale (AKPS), the Functional Index Questionnaire (FIQ), and the Pain Severity Scale (PSS) for patellofemoral pain syndrome (PFPS) into Brazilian Portuguese. This study also aimed to test the measurement properties of the AKPS, the FIQ, and the PSS, and the existing Brazilian Portuguese versions of the numeric pain rating scale (NPRS) and the Global Perceived Effect scale in a group with PFPS. BACKGROUND: PFPS is a common condition. Therefore, translated, culturally adapted, and clinimetrically tested instruments for measuring PFPS are needed. METHODS: The AKPS, FIQ, and PSS instruments were cross-culturally adapted into Brazilian Portuguese. The measurement properties of the AKPS, FIQ, PSS, NPRS, and Global Perceived Effect scale (internal consistency, ceiling and floor effects, and construct validity) were tested in 83 patients with PFPS. The reproducibility and responsiveness were tested in 52 patients with PFPS in a test-retest design, with follow-up testing at 48 to 72 hours and at 4 weeks after baseline. RESULTS: The AKPS, the FIQ, and the PSS yielded adequate internal consistency (Cronbach alpha ranging from .75 to .87) and excellent reliability (intraclass correlation coefficients [model 2,1] ranging from 0.90 to 0.97). The AKPS and the PSS yielded very good agreement (standard error of measurement, 2.9% and 3.5%, respectively). The highest correlations were observed among the AKPS, the FIQ, and the PSS (Pearson r>0.60, P<.05). No floor or ceiling effects were observed for any of the instruments. Effect sizes used for measuring internal responsiveness ranged from moderate to high for all measures. The NPRS and the AKPS were the measures with the highest external responsiveness. CONCLUSION: The Brazilian Portuguese versions of the AKPS, FIQ, PSS, NPRS, and Global Perceived Effect scale have acceptable measurement properties.

Cross-cultural adaptation and measurement properties of the Brazilian Portuguese Version of the Victorian Institute of Sport Assessment-Patella (VISA-P) scale.

STUDY DESIGN: Clinical measurement. OBJECTIVES: To translate, adapt, and test the measurement properties of the Brazilian Portuguese version of the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire. BACKGROUND: It is important to objectively measure symptoms and functional limitations related to patellar tendinopathy using outcome measures that have been validated in the language of the target population. Cross-cultural adaptations are also useful to enhance the understanding of the measurement properties of an assessment tool, regardless of the target language. METHODS: The VISA-P questionnaire was translated into Brazilian Portuguese, culturally adapted, and titled VISA-P Brazil. It was then administered on 2 occasions with a 24- to 48-hour interval between them, and a third time after a month of physical therapy treatment. The following measurement properties were analyzed: internal consistency, test-retest reliability, agreement, construct validity, floor and ceiling effects, and responsiveness. RESULTS: The VISA-P Brazil had high internal consistency (Cronbach α = .76; if item deleted, Cronbach α = .69-.78), excellent reliability and agreement (intraclass correlation coefficient = 0.91; 95% confidence interval: 0.85, 0.95; standard error of measurement, 5.2 points; minimal detectable change at the 90% confidence level, 12.2 points), and good construct validity (Pearson r = 0.60 compared to Lysholm). No ceiling and floor effects were detected for the VISA-P Brazil, and the responsiveness, based on 32 patients receiving physical therapy intervention for 1 month, demonstrated a large effect size of 0.97 (95% confidence interval: 0.68, 1.25). CONCLUSION: The VISA-P Brazil is a reproducible and responsive tool and can be used in clinical practice and research to assess the severity of pain and disability of patients with patellar tendinopathy.