Revisiting cardiac output estimated noninvasively from oxygen uptake during exercise: an exploratory hypothesis-generating replication study.

Stringer et al. [J Appl Physiol (1985) 82: 908-912, 1997] developed a method from invasive data to estimate cardiac output during incremental exercise testing based on Fick's principle. The authors proposed that the arterio-mixed venous oxygen content difference increases linearly with percentage of maximal O2 consumption. We hypothesized an S-shaped pattern in the published data and calculated the inflection point of this curve and of the standard resting oxygen dissociation curve. Using a partial F test, we compared the linear model with a third-order polynomial model, which showed a better fit to the data [F(2,101) = 9.5, P < 0.001]. This finding was reproduced in a dataset published by Åstrand et al. in 1964 [F(2, 122) = 10.6, P < 0.001]. The inflection point of the curve coincided with the lactate acidosis threshold [first ventilatory threshold (VT1)] as measured by Stringer et al. (VT1 at 50% and inflection point at 56% [95% CI, 52.9 to 60.7] of maximal O2 consumption). The inflection point of the standard resting oxygen dissociation curve was calculated at a partial pressure of 21.5 mmHg and a saturation of 36%, matching the "critical capillary Po2" concept of Stringer et al. (21.2 mmHg). We conclude that the arterio-mixed venous oxygen content difference increases in an S-shaped manner with percentage of maximal oxygen consumption and that the inflection point of this curve may correspond to VT1 and that of the in vivo oxygen dissociation curve. Further research is needed to confirm these findings and improve the method.NEW & NOTEWORTHY In 1997, Stringer, Hansen, and Wasserman developed a method for estimating cardiac output during incremental exercise testing. They observed that the arterio-mixed venous oxygen content difference increases linearly with the percentage of maximal O2 consumption. This increase may be better modelled by an S-shaped function, the inflection point of which may be related to the first ventilatory threshold and the inflection point of the oxygen dissociation curve. This finding may help to improve the method.

Comparison of the FRIEND and Wasserman-Hansen Equations in Predicting Outcomes in Heart Failure.

Background Percentage of age-predicted peak oxygen uptake (VO2) achieved (ppVO2) has been widely used to stratify risk in patients with heart failure. However, there are limitations to traditional normal standards. We compared the recently derived FRIEND (Fitness Registry and the Importance of Exercise: A National Data Base) equation to the widely used Wasserman-Hansen (WH) ppVO2 equation to predict outcomes in patients with heart failure. Methods and Results A subgroup of 4055 heart failure patients from the FRIEND registry (mean age 53±15 years) was followed for a mean of 28±16 months. The FRIEND and WH equations along with measured peak VO2 expressed in mL/kg-1 per min-1 were compared for mortality and composite cardiovascular events. ppVO2 was higher for the FRIEND versus the WH equation (66±30% versus 58±25%; P<0.001). The areas under the receiver operating characteristic curves were slightly but significantly higher for the FRIEND equation for mortality (0.74 versus 0.72; P=0.03) and cardiac events (0.70 versus 0.68; P=0.008). Area under the receiver operating characteristic curve for measured peak VO2 was 0.70 (P<0.001) for mortality and 0.73 (P<0.001) for cardiovascular events. For each 1-SD higher ppVO2 for the FRIEND equation, mortality was reduced by 18% (hazard ratio, 0.82; 95% CI, 0.69-0.97; P<0.02); for each 1-SD higher ppVO2 for the WH equation, the mortality was reduced by 17% (hazard ratio, 0.83; 95% CI, 0.71-0.97; P=0.02). The corresponding reductions in risk per 1 SD for cardiovascular events for the FRIEND and WH equations were 23 and 21%, respectively (both P<0.001). Conclusions Peak VO2 expressed as percentage of an age-predicted standard strongly predicts mortality and major cardiovascular events in patients with heart failure. The FRIEND registry equation exhibited test characteristics slightly superior to the commonly used WH equation.

Upper-Body Strength Endurance and Power Norms in Healthy Collegiate Dancers: A 10-year Prospective Study.

ABSTRACT: Coogan, SM, Hansen-Honeycutt, J, Fauntroy, V, and Ambegaonkar, JP. Upper-body strength endurance and power norms in healthy collegiate dancers: A 10-year prospective study. J Strength Cond Res 35(6): 1599-1603, 2021-Dance is physically demanding and requires dancers to have adequate upper body (UB), core, and lower-body fitness to perform successfully. 50-85% of dancers suffer injury during a performance season. Although a large number of dancer's injuries are to the lower body, several dance genres (e.g., modern, hip hop, and salsa) use UB motions such as partner lifts and holds, which may result in a higher risk for UB injury. Health care practitioners often use baseline physical performance normative values to determine their clients' fitness levels and when planning training programs to prevent or rehabilitate postinjury. Still, little information exists regarding UB fitness norms among collegiate dancers. Thus, our purpose was to determine UB strength endurance and power norms in healthy collegiate dancers. We recorded UB muscular fitness in 214 healthy collegiate dancers (males: n = 26, 174.0 ± 6.7 cm, 71.3 ± 9.2 kg and females: n = 188, 163.0 ± 6.1 cm, 59.3 ± 6.8 kg) prospectively over a 10-year period (2008-2018) in a dance program that emphasizes modern and ballet dance. For UB strength endurance, we recorded the number of push-ups a dancer was able to perform without forcibly straining or losing form for 2 consecutive repetitions. For UB power, dancers sat with legs outstretched, backs flat against a wall, and threw a 3-kg ball horizontally from their chest as far as possible (distance thrown normalized to body height, *BH). The best attempt of 3 trials was used for statistical analyses. We report descriptive statistics, interquartile ranges (IQRs), and percentiles for both outcome measures. Dancers performed 20.4 ± 10.6 (range: 2-70, IQR: 12-24; males: 32.5 ± 14.4; females: 18.4 ± 8.4) push-ups and threw the medicine ball 1.8 ± 0.5 *BH (range: 45-3.9, IQR: 1.4-2.1; females: 1.7 ± 0.5; males: 2.3 ± 0.7). Overall, in this long-term prospective study, we developed UB fitness norms for dancers. The push-up test and medicine ball throw test are simple, low-tech, and inexpensive to test dancers UB fitness. Although dancers' UB muscular fitness was lower than previous reports among traditional sport athletes, these values may not necessarily indicate problems, as subjects were all healthy collegiate-level dancers. Rather, our findings reinforce the need to develop dance-specific norms so that practitioners can use these values to assess dancers' UB fitness and devise interventions appropriately. These results provide baseline UB muscular fitness norms among collegiate modern and ballet dancers, and further support the notion that differing norms are needed for different sports and dance genres. Specifically, future researchers should similarly develop norms across different dance genres for preprofessional and professional dancers and also examine whether these norms can predict dancers' injury risk or performance.

Lower Extremity Horizontal Work But Not Vertical Power Predicts Lower Extremity Injury in Female Collegiate Dancers.

Ambegaonkar, JP, Schock, CS, Caswell, SV, Cortes, N, Hansen-Honeycutt, J, and Wyon, MA. Lower extremity horizontal work but not vertical power predicts lower extremity injury in female collegiate dancers. J Strength Cond Res 32(7): 2018-2024, 2018-Dancers often perform powerful and explosive movements that require adequate lower extremity (LE) activity in horizontal and vertical directions. We examined whether these measures were interrelated and whether they predicted LE injury status in dancers using binary logistic regressions and receiver operator characteristic (ROC) curve analyses. Forty-three collegiate female dancers (18 ± 0.7 years; 162.6 ± 5.9 cm; 59.4 ± 7.1 kg) performed single leg hop (SLH, m) and vertical jump (VJ, cm) tests. Single leg hop and VJ distances were used to calculate SLH norm (as a % of body height) and vertical power (vPower, watts). Lower extremity injuries and dance exposure hours (DEhrs) were recorded for 16 weeks. Dancers had 51 injuries resulting in a 3.7/1,000 DEhr injury incidence rate (95% confidence interval [CI]: 2.7-4.7). Twenty dancers were injured, whereas 23 remained injury free. Injured dancers had significantly lower SLH norm than noninjured dancers (t = 2.7, p = 0.009, 85.2 ± 11.2% vs. 76.8 ± 8.4%, respectively), but vPower was similar (t = 0.6, p = 0.53, injured = 2,632.0 ± 442.9 watts, noninjured = 2,722.7 ± 480.0 watts). SLH norm, but not vPower significantly predicted injury status χ(1,43) = 5.9, p = 0.02. Specifically, an SLH norm cut-off value of 78.2% identified dancers at injury risk (area under the curve = 0.73, SE = 0.08, p = 0.01, 95% CI = 0.57-0.89, sensitivity = 0.75, specificity = 0.70). However, vPower was not able to identify dancers at risk (p = 0.36). vPower had moderate relationships with SLH norm (r = 0.31, p = 0.04). Compared with injured dancers, noninjured dancers had greater SLH norm but similar vPower. Only SLH norm predicted injury status in female collegiate dancers. Thus, the SLH test may possibly predict LE injury risk in dancers. Strength and conditioning coaches can prospectively use baseline SLH test screenings to identify dancers whose SLH is less than 78.2% of their height because these dancers may have increased probability of LE injury risk. Coaches can then include horizontal direction exercises when designing training programs and examine whether these programs reduce LE injury risk in female collegiate dancers.

Applying current normative data to prognosis in heart failure: The Fitness Registry and the Importance of Exercise National Database (FRIEND).

INTRODUCTION: Percent of predicted peak VO2 (ppVO2) is considered a standard measure for establishing disease severity, however, there are known limitations to traditional normative values. This study sought to compare ppVO2 from the newly derived "Fitness Registry and the Importance of Exercise: a National Database" (FRIEND) registry equation to conventional prediction equations in a clinical cohort of patients undergoing cardiopulmonary exercise testing (CPX). METHODS AND RESULTS: We selected 1094 patients referred for evaluation of heart failure (HF) symptoms who underwent CPX. ppVO2 was calculated using the FRIEND, Wasserman/Hansen and Jones equations. Participants were followed for a median of 4.5 years [Interquartile range 3.5-6.0] for the composite endpoint of death, advanced HF therapy, or acute decompensated HF requiring hospital admission. Mean age was 48 ±â€¯15 years and 62% were female. The FRIEND registry equation predicted the lowest ppVO2 (measured/predicted; 71 ±â€¯31%), compared to the Wasserman/Hansen (74 ±â€¯29%) and Jones equations (83 ±â€¯33%) (p < 0.001). All expressions of peak VO2 were significant as univariate predictors of outcome with no significant differences between equations on pairwise analysis of receiver operating characteristic curves. When compared at a similar threshold of ppVO2 the event rate was significantly lower in the FRIEND registry equation versus the currently used Wasserman and Jones equations. CONCLUSION: The use of the newly derived FRIEND registry equation predicts HF outcomes; however, it appears to predict a higher predicted VO2; the clinical implication being a lower threshold of percent predicted peak VO2 should be considered when risk stratifying patients with HF.

A non-exercise based V02max prediction using FRIEND dataset with a neural network.

The main goal of this work is the development of models, based on computational intelligence techniques, in particular neural networks, to predict the maximum oxygen consumption value. While the maximum oxygen consumption is a direct mark of the cardiorespiratory fitness, several studies have also confirmed it also as a powerful predictor of risk for adverse outcomes, such as hypertension, obesity, and diabetes. Therefore, the existence of simpler and accurate models, establishing an alternative to standard cardiopulmonary exercise tests, with the potential to be employed in the stratification of the general population in daily clinical practice, would be of major importance. In the current study, different models were implemented and compared: 1) the traditional Wasserman/Hansen equation; 2) linear regression and; 3) non-linear neural networks. Their performance was evaluated based on the "FRIEND - Fitness Registry and the Importance of Exercise: The National Data Base" [1] being, in the present study, a subset of 12262 individuals employed. The accuracy of the models was performed through the computation of sensitivity and specificity values. The results show the superiority of neural networks in the prediction of maximum oxygen consumption.

Physical Fitness and Body Composition in 8-10-Year-Old Danish Children Are Associated With Sports Club Participation.

Larsen, MN, Nielsen, CM, Ørntoft, CØ, Randers, M, Manniche, V, Hansen, L, Hansen, PR, Bangsbo, J, and Krustrup, P. Physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. J Strength Cond Res 31(12): 3425-3434, 2017-We investigated whether physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. The study included 423 schoolchildren, comprising 209 girls and 214 boys, of whom 67 and 74%, respectively, were active in sports clubs. Yo-Yo intermittent recovery level 1 for children (YYIR1C), balance, jump and coordination tests, together with dual-energy X-ray absorptiometry, were used to determine exercise capacity and body composition. Children active in sports clubs had better (p < 0.05) YYIR1C (33%, 767 ± 26 vs. 575 ± 29 m), 20-m sprint (3%, 4.33 ± 0.03 vs. 4.48 ± 0.04 seconds), coordination (6%, 68 ± 1 vs. 72 ± 1 second), and balance test performances (9%, 19.3 ± 0.5 vs. 21.2 ± 0.7 falls·min) and lower fat mass index (16%, 3.8 ± 0.1 vs. 4.5 ± 0.2 kg[fat]·m) than children not active in sports clubs. Ball game players had better (p < 0.05) YYIR1C (38%, 925 ± 39 vs. 671 ± 28 m), 20-m sprint (4%, 4.25 ± 0.03 vs. 4.42 ± 0.04 seconds), and coordination test performances (5%, 65 ± 1 vs. 69 ± 1 second), along with higher (p < 0.05) lean body mass (5%, 24.00 ± 0.22 vs. 22.83 ± 0.25 kg) and whole-body BMD (2%, 0.90 ± < 0.01 vs. 0.88 ± <0.01 g·cm) compared with children active in other sports. The study showed that 8[FIGURE DASH]10-year-old Danish children engaged in sports-club activity, especially ball game players, have better exercise capacity and superior body composition compared with children not active in sports clubs.

A Delphi exercise to refine the WHO three-point disability grading system for leprosy, and to develop guidelines to promote greater accuracy and reliability of WHO disability recording.

A Delphi Exercise was undertaken with two objectives: (1) To ascertain whether operational definitions for WHO Disability Grading could be formulated by consensus. (2) To develop a set of simple guidelines based on those definitions for the guidance of health workers. Fifteen people with general expertise in prevention of disability due to leprosy were invited to participate as Delphi panel members, twelve responded positively. Eight issues that commonly cause confusion provided foci for the exercise. Operational definitions aimed at resolving those issues were developed by consensus. Simple guidelines for health workers, based on those definitions were also created and supported by consensus. This paper presents the process followed and the outcomes gained from the endeavour.

Effectiveness of social skills training for reduction of self-perceived stigma in leprosy patients in rural India--a preliminary study.

OBJECTIVES: To assess the effectiveness of social skills training in leprosy patients to raise self-esteem and reduce self-perceived stigma. DESIGN: Five leprosy patients were given 10 day-long group-sessions of social skills training over 3 weeks. Training involved: identification of the emotions and concerns of patients when interacting socially; analysis of positive and negative social interactions and non-verbal and verbal skills training. Role-plays, videos and live models were used. Self-esteem and a reduction in self-perceived stigma were assessed qualitatively before and after training using semi-structured interviews. Assessment of change was scored under the indicators: self-perception, family, wider community and job. Patients were assessed for displaying new ways of interacting with people and changes in expectations for the future. RESULTS: Qualitative analysis of the interviews before and after training suggested that social skills training could raise the self-esteem of leprosy patients and combat self-perceived stigma. Increase in self-esteem, as evident through the verbal interactions with the interviewers and behavioural changes in the community, were noted in the majority of patients. CONCLUSION: Social skills training along with counseling may be able to increase the self-esteem of leprosy patients, and so be a useful part of leprosy rehabilitation schemes to try and combat the stigma of leprosy.

Progression of bone lesions in cured leprosy patients.

A group of 52 patients deemed to be cured of Hansen's disease were examined in order to determine the appearance or aggravation of bone lesions after cure. A study was made of X-rays performed both at the moment these patients were considered to be cured and a minimum of 2 years later. During the elapsing interval, new lesions had appeared in 8 patients, and existing lesions had worsened in 12 patients. Factors associated with the progression of lesions were: impaired sensitivity, physical activity and appearance of plantar ulcers. The authors feel that leprosy patients, even when considered to be bacteriologically cured, should undergo regular checkups. Factors which might aggravate bone lesions should be borne in mind.

Programa de fortalecimento para músculos da mao (abdutor do quinto dedo, primeiro interosseo dorsal, oponente do polegar, interósseos e lumbricais, e extensores do punho), e do pé (tibial anterior e extensores dos artelhos) / Strength training program for hand muscles (abductor of the fifth finger, first dorsal interosseous, opponent of the thumb, interosseous and lumbricals, and wrist extensors), and of the foot (anterior tibial and extensors of the toes)

O desenvolvimento do tema desta monografia foi proposto para atender às necessidades de pacientes com quadro de fraqueza muscular, decorrente de neuropatia hansênica, atendidos no Setor de Fisioterapia do Instituto "Lauro de Souza Lima". A partir de revisao de literatura, referente ao período de 1970 à 1995, salienta-se a necessidade de considerar as variáveis que interferem na obtençao do fortalecimento muscular e propoe-se um programa através de exercícios isométricos, para os músculos da mao e do pé mais acometidos na hanseníase. Para a relizaçao destes exercícios, recomenda-se o uso de resistência direta constante, carga avaliada através da resistência máxima estática (RM estática), mantida por 1 segundo, número de repetiçoes de 5 exercícios, dentro de uma única série, sendo o tempo de cada repetição de 6 segundos, adotando posição articular a cada 10°, com frequencia de exercícios diário, uma vez ao dia.