Estimated VO2 Max Research Articles

"Tailored“ Step Test For Rapid, Accurate And Safe Vo2max Determination In Healthy Elderly.

PURPOSE: The study aimed at developing and validating a "tailored“ version of the Åstrand step test, suitable for VO2max determination in healthy elderly. Furthermore, we tested the hypothesis that a direct measure (compared to estimation) of the step test VO2, adds accuracy to VO2max determination in this population, characterized by low fitness and muscle strength and reduced coordiantive ability. METHODS: In 27 healthy elderly (age 68+5, 14 M, 13 F) a target VO2 (tVO2) for the step test was calculated as 60% of the VO2max (predicted based on their referred activity pattern). Thereafter, subjects performed a 5-min test, on a 30 cm step, with a stepping rate (10-25 steps*min-1) "tailored“ based on tVO2 and the predicted cost of stepping. Heart rate (HR) and VO2 were measured using a portable, hand-held, metabolic analyzer. VO2max was estimated based on Åstrand equation and age correction using either tVO2 (t-estVO2max) or measured VO2 (m-estVO2max). Finally, VO2max was measured directly (dVO2max) during an incremental cycling test to exhaustion with breath by breath determination of cardiorespiratory variables, with a traditional metabolic chart. Agreement among t-estVO2max, m-estVO2max and dVO2max was evaluated by Bland Altman analysis. RESULTS: All the subjects completed the incremental exercise to exhaustion (maximal HR 98±7% of age-predicted value, maximal respiratory quotient 1.1±0.04). Mean ± standard deviation dVO2max was 27±5 ml*kg-1*min-1. All the subjects were also able to complete the "tailored“ step test with no difficulty. m-estVO2max was not significantly different from dVO2max (bias -0.3, not different from 0; precision 4.1 ml*kg-1*min-1). On the contrary, t-estVO2max was significantly underestimated compared to dVO2max (bias -2.3, ≠ 0; precision 4.6 ml*kg-1*min-1). CONCLUSION: The study developed and validated a "tailored“ version of the Åstrand step test, suitable for a rapid (5 min duration), safe (submaximal test) and accurate (unbiased) VO2max determination in healthy elderly individuals. In this population, estimation of the step test VO2 leads to a small (9%) yet significant error in VO2max estimation. Therefore, our data suggest that a direct measure of the step test VO2 should be performed to assure accuracy to VO2max.estimation. The study was Supported by Cosmed, Italy.

Validation Of The Cosmed Fitmate For Predicting Maximal Oxygen Consumption

PURPOSE: The primary purpose of this study was to assess the validity of the Cosmed Fitmate (FM) in predicting maximal oxygen consumption (VO2max), compared to the Douglas bag (DB) method. In addition, this study examined whether measuring submaximal VO2, rather than predicting it, can improve upon the prediction of VO2max. METHODS: Thirty-two males and sixteen females (Mean ± SD: age 30 ± 9 yr, body mass 72.9 ± 13.0 kg, height 1.75 ± 0.09 m, BMI 23.4 ± 3 kg·m-2) volunteered to participate in the study. Each participant completed a submaximal and a maximal treadmill test using the Bruce protocol on two separate occasions. During the submaximal test, VO2max was predicted using the FM, while during the maximal test VO2max was measured using the DB method. The Cosmed Fitmate predicts VO2max by extrapolating the linear regression relating heart rate and measured VO2 to age-predicted maximum heart rate (HR = 220-age). This study also examined the validity of predicting VO2max by using the ACSM metabolic equations to estimate submaximal VO2. VO2max values from the FM, the DB method, and ACSM prediction equations were analyzed using repeated measures ANOVA and linear regression analyses. The level of significance was set at P < 0.05 for all statistical analyses. RESULTS: There was no significant difference between VO2max predicted by the FM (45.6 ml·kg-1·min-1, SD 8.8) and measured by the DB method (46.5 ml·kg-1·min-1, SD 8.8) (p = 0.152). The results of this study showed that a strong positive correlation (r = 0.897) existed between VO2max predicted by the FM and VO2max measured by the DB method, with a standard error of the estimate (SEE) = 3.97 ml·kg-1·min-1. There was a significant difference in VO2max predicted by the ACSM metabolic equations (53.6 ml·kg-1·min-1, SD 8.0) and VO2max measured by the DB method (p = 0.01). The correlation between these variables was r = 0.699 (SEE = 5.84 ml·kg-1·min-1). CONCLUSION: These findings suggest that the Fitmate is a small, portable, and easy-to-use metabolic system that provides reasonably good estimates of VO2max, and that measuring submaximal VO2, rather than predicting it from the ACSM metabolic equations, improves the prediction of VO2max.

SP30 Studying Fitness Status of Healthy Middle-Aged Greek Individuals by Maximum Oxygen Consumption (Vo2Max) Estimation during Cardiopulmonary Exercise Test

SP30 Studying Fitness Status of Healthy Middle-Aged Greek Individuals by Maximum Oxygen Consumption (Vo2Max) Estimation during Cardiopulmonary Exercise Test

Prediction of Maximum Oxygen Uptake Using Both Exercise and Non-Exercise Data

This study sought to develop a regression model to predict maximal oxygen uptake (VO2max) based on submaximal treadmill exercise (EX) and non-exercise (N-EX) data involving 116 participants, ages 18–65 years. The EX data included the participants' self-selected treadmill speed (at a level grade) when exercise heart rate first reached at least 70% of predicted maximum heart rate (HRmax; 220 – age) by the end of any one of three 4-min consecutive stages involving walking (3.0–4.0 mph; Stage 1), jogging (4.1–6.0 mph; Stage 2), and running (> 6.0 mph; Stage 3). The N-EX data included various demographic (age, gender), biometric (body mass), and questionnaire (participants' perceived functional ability [PFA] to walk, jog, or run given distances, and their self-reported level of physical activity [PA-R]) information. All participants (n = 100) who completed the study requirements and successfully achieved a maximal level of exertion during a graded exercise test (GXT) to assess VO2max (mean ± SD; 41.39 ± 9.15 ml · kg−1 · min−1) were included in the data analysis. Stepwise regression was used to generate the following prediction equation (R = .94, SEE = 3.09 ml · kg−1 · min−1): VO2max (ml · kg−1 · min−1) = 30.04 + (6.37 × gender; females = 0, males = 1) – (0.243 × age) – (0.122 × body mass) + (3.263 × ending self-selected treadmill speed; mph) + (0.391 × PFA) + (0.669 × PA-R). Each of the predictor variables were statistically significant (p < .001) and cross-validation procedures using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (Rp = .92 and SEE p = 3.29 ml · kg−1 · min−1). In summary, this submaximal treadmill test and accompanying regression model yields relatively accurate VO2max estimates in healthy men and women (ages 18–65 years) using both EX and N-EX data.

The usability of a modified Åstrand bicycle test to assess the aerobic capacity in patients with musculoskeletal pain and healthy controls

Purpose. The aim of this study was to assess the usability of a modified Åstrand bicycle test in subjects with musculoskeletal pain disorder (MSPD) and healthy controls.Methods. In a random cross-over design, 31 subjects with a MSPD who have been referred to rehabilitation medicine and 33 healthy subjects matched for age, gender, height and body weight, performed an Åstrand bicycle test and a modified test with a time interval of 7 days. Drop-out rates, VO2max values (in mL/kg lean body mass (LBM) min−1), intraclass correlation coefficients (ICCs) and critical difference (Bland-Altman plots) for both tests within each group of subjects were compared.Results. The drop-out rate in both tests for the MSPD group was comparable, and mainly caused by pain, fatigue or breathlessness. Compared with the modified version, the Åstrand test showed higher VO2max-scores: 4.83 mL/kg LBM min−1 (9.96%) in the MSPD group and 3.5 mL/kg LBM min−1 (5.57%) in the healthy group. ICCs were 0.79 and 0.87 and the limits of agreement were 8.5 mL/kg LBM min−1 (15.9%) and 10.2 mL/kg LBM min−1 (18.1%), respectively.Conclusion. The usability of the modified test is acceptable, as well as in healthy individuals as subjects suffering from MSPD being referred to rehabilitation medicine. However, a slight under estimation of VO2max with the modified test has to be taken into account.

Comparação entre as modalidades de caminhada e corrida na predição do consumo máximo de oxigênio

Os testes ergométricos de exercício realizados em esteira podem ser desempenhados a partir das modalidades de caminhada e corrida, contudo, sem haver grandes elucidações ao comparar resultados de VO2máx obtidos nessas possibilidades de teste. Com o intuito de responder a essa questão, o presente estudo objetivou comparar a predição do VO2máx entre um protocolo escalonado máximo de caminhada e um de corrida, ambos elaborados de modo a proporcionar demandas metabólicas idênticas em cada estágio. Foram voluntários para o presente estudo 23 indivíduos (15 masculinos e oito femininos) com 27,7 ± 7,6 anos de idade, 73,0 ± 14,9kg de massa corporal, 170,0 ± 1,0cm de estatura, 19,3 ± 8,6% de gordura corporal, 24,7 ± 3,3kg×m-2 de índice de massa corporal e 44,1 ± 6,0mL×kg-1×min-1 de potência aeróbia máxima. Um teste t pareado não demonstrou diferenças significativas (p = 0,364; IC 95 % = -2,2 a 0,85) entre o protocolo de caminhada e o de corrida, apesar de a média dos valores do VO2máx na corrida ter sido 2,4% superior (42,4 vs. 43,4mL×kg-1×min-1). Com base nos resultados encontrados, conclui-se que a administração de diferentes estratégias de protocolos em esteira (caminhada ou corrida) não influenciou significativamente a estimativa do VO2max, não interferindo na posterior tomada de decisão para a prescrição do treinamento cardiorrespiratório.

Moderate intensity exercise training reverses functional aerobic impairment in HIV-infected individuals

HIV infection and HIV drug therapies result in physical and psychological challenges to those living with HIV. These conditions contribute to decreased functional aerobic capacity (FAC). The aim of this study was to determine the effects of a combined moderate-intensity aerobic and resistance exercise intervention on the FAC of HIV-infected individuals. Forty HIV-infected individuals were randomized to an exercise group (EX) who completed six weeks of moderate-intensity exercise training, or to a control group (CON) that did not receive the exercise intervention. Twice weekly, the EX group completed 30 minutes of moderate-intensity aerobic training followed by moderate-intensity resistance training. Prior to, and following, the intervention the FAC for each subject was determined by graded exercise treadmill stress test (GXT). At baseline testing, the mean FAC as determined by treadmill time-based estimation of maximal oxygen consumption was 25% below age-predicted values, a level of reduction indicating the presence of functional aerobic impairment (FAI). Following the intervention, the EX had a significant increase in time to fatigue and estimated VO2 max (p<.001). Further, FAI was eliminated (1% above age predicted values) during the exercise training. The EX group also experienced decreased heart rates during Stages 1 (p=.02), 2 (p=.01), 4 (p=.05) and 6 (p=.02) of the GXT. The CON had no significant changes during the intervention period. These data indicate that six weeks of combined moderate-intensity aerobic and resistance training can improve FAC and eliminate FAI in those with HIV. Results suggest that the functional limitations common in HIV-infected individuals are due in part to detraining that is reversible through moderate exercise adherence.

Artificial neural network-based equation for estimating VO2max from the 20 m shuttle run test in adolescents

To develop an artificial neural network (ANN)-equation to estimate maximal oxygen uptake (VO(2max)) from 20m shuttle run test (20 mSRT) performance (stage), sex, age, weight, and height in young persons. The 20 mSRT was performed by 193 (122 boys and 71 girls) adolescents aged 13-19 years. All the adolescents wore a portable gas analyzer to measure VO(2) and heart rate during the test. The equation was developed and cross-validated following the ANN mathematical model. The neural net performance was assessed through several error measures. Agreement between the measured VO(2max) and estimated VO(2max) from Léger's and ANN equations were analysed following the Bland and Altman method. The percentage error was 17.13 and 7.38 for Léger and ANN-equation (P<0.001), respectively, and the standard error of the estimate obtained with Léger's equation was 4.27 ml/(kg min), while for the ANN-equation was 2.84 ml/(kg min). A Bland-Altman plot for the measured VO(2max) and Léger-VO(2max) showed a mean difference of 4.9 ml/(kg min) (P<0.001), while the Bland-Altman plot for the measured VO(2max) and ANN-VO(2max) showed a mean difference of 0.5 ml/(kg min) (P=0.654). In the validation sample, the percentage error was 21.08 and 8.68 for Léger and ANN-equation (P<0.001), respectively. In this study, an ANN-based equation to estimate VO(2max) from 20 mSRT performance (stage), sex, age, weight, and height in adolescents was developed and cross-validated. The newly developed equation was shown to be more accurate than Léger's. The proposed model has been coded in a user-friendly spreadsheet.

Is the Cardiorespiratory Fitness Affected by Height of Young Girls?

The purpose of the present study was to examine the effect of height in the predicted VO2max by the Queens Step test among short and tall young girls. A sample of 38 individuals was selected in two stages from a total of 500 individuals and was assigned to two groups of short (n = 20) and tall (n = 18). In order to examine the effect of height in the predicted VO2max, the Queens step protocol and the incremental treadmill speed test were used. Respiratory exchange was measured continuously throughout the test by an automated open-circuit gas analysis system. The study results showed that tall girls revealed a higher VO2max on the Queen's step and treadmill tests than short girls (Queen's: 44.09+/-2.66 vs. 38.96+/-1.65; Treadmill: 34.03+/-7.26 vs. 28.15+/-5.09 mL/kg/min). Based on the obtained findings it can be concluded that the higher VO2max seen in tall girls on the both protocols, may be due to their physiological and physical properties; therefore, it seems that designing of the adjustable steps to the height of subjects for optimizing the estimation of VO2max is not necessary and other physiological factors may be involved, which require further investigation.

The Effect of Physical Activity on Weight Loss in College Students

Weight loss is possibly the major reason that most people begin an exercise program. It has been used in many populations to help with weight loss. PURPOSE: To examine the effects of two different physical training programs on weight loss, body composition, and oxygen consumption in overweight individuals. METHODS: Twenty sedentary, overweight college-age students (6 males, 14 females, 22.6 Ãâ~Ã'± 8.2 y, BMI = 27.76 Ãâ~Ã'± 6.03) volunteered to participate in this study. After signing an informed consent form, they were randomly assigned to either a cardiovascular (C) training group (n = 10) or a strength and cardiovascular (S) training group (n = 10). The C group was required to accumulate 60 minutes of brisk walking 4 days per week. The S group performed 30 minutes of brisk walking 4 days per week, plus two strength training sessions each week. Anthropometric measures (height, weight, BMI, circumference measures, percent body fat, and fat-free mass) and cardiorespiratory fitness were collected before and after the 12-week exercise intervention. RESULTS: The attrition rate was 10% of the S group and 40% of the C group, which equals 25% of the total number of subjects who began the study. The S group finishers (n = 9) gained 1.27 kg (gained 1.95 kg of fat, and lost 0.68 kg of lean body mass), while the C group finishers (n = 6) lost 0.75 kg (gained 0.44 kg of fat and lost 1.19 kg of lean body mass). These changes were not significantly different within or between groups. The S group significantly increased body fat percentage by 2.27 Ãâ~Ã'± 2.31% (p = .019), whereas the C group had no change in body fat percentage (0.78 Ãâ~Ã'±1.90 %). Finally, the S group increased their estimated VO2 max (0.90 Ãâ ~Ã'± 2.05 mLÃâ~Ã'·kg-1Ãâ ~Ã'·min-1), although it was not significant. The C group had relatively no change in estimated VO2 max (0.10 Ãâ~Ã'± 4.62 mLÃâ~Ã'·kg-1 Ãâ ~Ã'·min-1), despite walking twice as much as the S group. CONCLUSIONS: These results support previous research reporting that exercise interventions produce only minimal changes in body weight without a change in dietary intake. Therefore, additional research is needed with a larger sample size and possibly diet modification to determine if combining strength training with cardiovascular training is superior to cardiovascular training alone for weight loss.

An Employee-fitness-based Corporate Bonus System: A Comparison Of Two Methods

PURPOSE: In 2005 a Dutch insurance company implemented an individual bonus system based on the scores of a yearly submaximal bicycle ergo meter test (Ästrand test) in an attempt to motivate office employees to be more physically active. Employees acquired a bonus if they had a high or very high fitness level according to the five fitness-levels of Ästrand. An 'improvement-bonus' was obtained if an increase of at least one fitness level was achieved compared to the year before (method 1). Because even a small increase in VO2max may result in achieving a higher fitnesslevel according to the Ästrand categorization of fitness levels and therefore a bonus should be given, an alternative method (method 2) was developed, based on changes in the submaximal heart rate (HR) measured in the last minute of the Ästrand test. It is assumed that a decrease in HR with an identical test load (Watt) is a better indicator of improved physical fitness, than an estimate of VO2max and the subsequent categorization over levels of fitness. The goal of this study is to examine the level of agreement between both methods, subsequently comment on whether method 2 may be preferable within the goal of the corporate bonus system. METHODS: In 2006 and 2007, 229 employees (58% female) performed the Ästrand test. To be included in the comparison the difference in test-load between both tests had to be+/−10W or less (n=135). Body composition (%body fat, body weight and height) were also measured. Descriptive statistics (e.g. cross-tabulations) were used. RESULTS: In 2007, 45.9% (n=62) would have received an improvement-bonus according to method 1 and 40.7% (n=53) according to method 2. The level of agreement of the two methods was 72.2% (n=45); 13.7% would have obtained an improvementbonus according to method 2, but not according method 1. However employees in this group had a substantial average decrease in HR of−12.3bpm (SD=6.1; range−28 to−8). In contrast: 27.4% scored 'no bonus' on method 2 and 'bonus' on method 1, with an average decrease in HR of−4.8bpm (SD=3.4, range:−9 to 5). CONCLUSIONS: A HR-based improvement-bonus may be an improvement to the corporate bonus system, because it includes employees who increased their physical fitness (i.e. a substantial decrease in HR) but who would be excluded from receiving a bonus based on VO2max categorization and vise versa.

Relationships Between Blood Lactate Clearance and Measures of Aerobic Capacity in Elite Women's Ice Hockey

Successful performance in ice hockey relies on a combination of anaerobic and aerobic energy systems. The relationships between blood lactate and indirect measures of aerobic capacity have not been investigated in elite female ice hockey players. PURPOSE: To determine relationships between blood lactate clearance, the difference between lactate immediately following an on-ice Repeat Sprint Skate Test (RSS) (Bracko & George, 2001) and lactate after 4-6 mins recovery, and other measures of aerobic capacity in elite female ice hockey players. METHODS: Players on the University of Alberta women's ice hockey team (n=80, 21.1±2.6 yrs) completed pre-season tests of aerobic fitness (Leger test [Leger, 1988]) (off-ice) and RSS. Blood lactate clearance, drop-off times on RSS (difference between first and third repeat), heart rate drop-offs (post-RSS HR - recovery HR differences), and Leger test estimates of VO2max were used as proxies for aerobic capacity. Bivariate Pearson correlations were run (SPSS Mac Version 10.0), with a significance level set a priori at p<0.05. RESULTS: No significant relationships were found between lactate clearance and any aerobic measures (r= −.034 to .113, p>0.10). However, higher VO2max estimates from the Leger test were significantly related to better scores for on-ice measures of aerobic capacity (RSS drop-off, r=-.460, -.490, p=.000; HR drop-off; r=.293, p =.017). CONCLUSIONS: Lactate clearance is not related to on and off-ice measures of aerobic capacity in elite female hockey players; however, high predicted VO2max is correlated to better drop-off time and HR recovery after sprint skating.

Overall and peripheral ratings of perceived exertion during a graded exercise test to volitional exhaustion in individuals of high and low fitness

This study assessed the relationship between differentiated ratings of perceived exertion (RPE) and heart rate with oxygen uptake (VO2) during two graded exercise tests (GXT) to exhaustion on a cycle ergometer in 49 men and women (19-50 years) of high and low fitness. The study also assessed whether sub-maximal RPE values elicited during the GXTs could provide appropriate estimates of maximal aerobic power (VO2max) Peripheral RPE (RPEP) was higher than overall RPE (RPEO) at exhaustion in both groups (P<0.001), but the reliability of the terminal RPEO was higher (0.75 and 0.40, respectively). Fitness did not moderate the relationship of RPEO and RPEP with VO2 during the GXTs (P>0.05). However, the correlation for RPEP and VO2 was higher for women compared to men (0.98 and 0.96, respectively, P<0.05), although this is of little practical significance. In both groups, RPEO was almost as highly correlated with VO2 as heart rate during GXTs terminated at exhaustion (approximately 0.955-0.980). There were no differences between predicted and measured VO2max when VO2 values were extrapolated from sub-maximal RPEO (13, 15 and 17) intensities (42.1+/-12.5, 43.4+/-11.5, 44.2+/-11.3 and 43.3+/-10.0 ml kg(-1) min(-1), respectively). However, VO2max predicted from sub-maximal RPEP intensities was significantly lower (P<0.05). In conclusion, terminal RPEO was a more reliable measure of the RPE, and provided more accurate estimates of VO2max in healthy participants of high and low fitness when elicited from sub-maximal exercise intensities.

Fitness and physical activity in Norwegian adults

To date there is scant knowledge about cardio-respiratory fitness in the general adult population. The aims of the present study were to assess physical activity and fitness level in adults, and to obtain practical experience with field testing in the adult population. Employees in a rural municipality (n=925) were invited to answer a questionnaire about physical activity and participate in the UKK 2-km Walk Test. Sixty per cent (n=554) answered the questionnaire and 42% (n=388) performed the test. Sixty per cent of the men and 32% of the women had a body mass index ≥25. Twenty-three per cent of the participants were physically active ≥30 min/day. Estimated VO2 max (±SD) was 39.1±8.9 for men and 32.0±5.9 for women. The Walk Test was well received by participants and easy to arrange. The Norwegian adult population was not as fit as expected. The feasibility of the test was good. However, it is important to develop strategies to increase participation rates in future fitness tests and surveillances.

Effects of exercise and nutritional counseling in women with polycystic ovary syndrome

This pilot study assessed the effects of exercise and nutritional counseling on hormonal, menstrual, and reproductive function in women with polycystic ovary syndrome (PCOS). Twelve females with a clinical, biochemical, and ultrasonographic diagnosis of PCOS were randomly assigned to endurance and resistance exercise plus nutritional counseling (EN) or nutritional counseling only (N) for a period of 12 weeks. Anthropometry, resting metabolic rate (RMR), selected hormones, and ovarian follicle population were measured pre and post-intervention. Following the 12 week intervention, greater decreases in sum of 2 skinfolds (p = 0.002) and a greater increase in estimated VO2 max (p = 0.017) occurred in the exercise group. Significant decreases in waist girth (p = 0.001) and insulin levels (p = 0.03) occurred in both groups. Hormonal changes were not statistically significant; however, a trend towards an improved hormonal profile, specifically sex-hormone binding globulin (EN, 39% increase; N, 8% increase) and lutenizing hormone : follicle-stimulating hormone (LH:FSH) (EN, 9% decrease; N, 27% decrease) occurred in the absence of weight loss. These findings suggest exercise and nutritional counseling may benefit the metabolic and reproductive abnormalities associated with PCOS.

Validation of the Polar S410 Heart Rate Monitor for Estimating Energy Expenditure in Women

PURPOSE: To determine the effect of ambient temperature on the validity of the Polar S410 heart rate (HR) monitor for estimating energy expenditure. (EE) METHODS: EE estimates obtained during cycling at 30%, 60%, and 80% of maximal oxygen uptake (VO2max) in 25°C, 30°C, and 35°C ambient temperatures were compared with indirect calorimetry (IC). Three different methods of estimating EE using the monitor were compared: (a) the AHR method used the actual values for HRmax and VO2max, (b) the PHR method used the HRmax and VO2max predicted by the “OwnIndex” software, with resting HR measured in the ambient temperature for the test, (c) and the PHRTM method used the HRmax and VO2max predicted by the “OwnIndex” software, with resting HR measured in thermoneutral (22°C) conditions. The traditional method of using individualized heart rate-VO2 relationship to estimate EE was also compared to IC and the Polar S410 methods. RESULTS: In the 25°C, 30°C, and 35°C conditions AHR overestimated (means ± SD) EE from IC by 4% ±11, 7% ±11, and 9% ±8; PHR overestimated EE from IC by 17% ±21,18% ±22, and 19% ±19; PHRTM overestimated EE from IC by 20% ±21, 22% ±21, and 24% ±19; and the HR-VO2method underestimated EE from IC by 8% ±12, 4% ±12, and 1.4%±11. CONCLUSION: We conclude that the Polar S410, using the actual values for HRmax and VO2max programmed into the Polar S410 (AHR), provides estimates of EE for a group of young women that are within 10% of those from IC. These EE estimates are similar in accuracy (i.e. 4%–9% difference) to estimates from the traditional HR-VO2 relationship (i.e. 1.4%–8% difference). Estimates of EE from the Polar S410 based on estimates of VO2max and HRmax (PHR and PHRTM) are unacceptably high (>10%), with errors ranging from 17%–24%. Ambient temperatures above 25°C increase the error of EE estimates from the Polar S410 due to the dissociation of HR from VO2, resulting in EE estimates that are significantly different from IC.

Validation of an Ice Specific Endurance Test

No specific performance test exists for figure skating. Such a test would allow coaches and athletes in ice based sports to measure responses to training, and track changes in performance. PURPOSE: To develop an Ice Specific Endurance (ISE) test to estimate maximal oxygen uptake in figure skaters and establish the validity of the test. METHODS: Twenty-three skaters (mean ± SD) age 20.9 ± 13.1 years, height 162.2 ± 11.0 cm, weight 54.9 ± 12.6 kg with at least three years skating experience were tested over a 3 week period performing four tests, in random order; two skating protocols (a 31 meter rounded rectangle and a 37.5 figure of eight), a 20 meter running multistage fitness test (Léger and Lambert 1982) and a cycle ergometer VO2 max test. Linear regression plots established regression equations to predict VO2 max from each skating protocol. An ANOVA assessed the differences between measured and predicted VO2 max. RESULTS: Maximal oxygen uptakes (ml.kg-1.min-1) values were (mean ± SD) rounded rectangle (38.96 ± 7.87), figure of eight (38.98 ± 8.79), shuttle run (38.51 ± 8.24) and VO2 max (38.95 ± 8.87). Pearson product moment correlations between final level obtained during the two ISE tests and measured VO2 max for the 31 meter rounded rectangle and the figure of eight were r = 0.89 (p<0.01) R2 = 89%, and r = 0.99 (p<0.01) R2 = 99% respectively. A one way within-subject ANOVA performed using predicted VO2 max values for each ISE test, the shuttle run test values (Ramsbottom et al. 1998) and measured VO2 max, showed that there was no statistically significant difference between the tests. CONCLUSION: No statistically significant difference was found between measured VO2 max and all predictive tests suggesting all three tests are valid estimates of a skaters VO2 max. The 37.5 meter figure of eight ISE test appears the most valid predictive measure of VO2 max and we recommend the use of this test for measuring aerobic performance in figure skating.

A Comparison of Physical Fitness in Sighted and Visually Impaired Individuals

Visual impairment or blindness (VI) has been associated with low physical fitness levels when compared to sighted (SI) individuals. A majority of the research addressing fitness in the visually impaired has been conducted on children and adolescents. PURPOSE: The purpose of this study was to investigate the differences in physical fitness between VI and SI adults. METHODS: Fifty volunteers ranging from 18 to 60 years (33.14 ± 1.81) volunteered for this study: 26 SI (male = 14, female = 12) and 24 VI (male= 13, female = 11). Anthropometric measures included height, weight, body mass index, percentage body fat (3-site skinfold), waist and hip measurements. Physical fitness evaluation included: Submaximal VO2 bicycle ergometry, handgrip strength, push-ups, curl-ups, lower back flexibility (sit and reach), reaction time and balance. Participation in physical activity (cardiovascular, muscular strength, muscular endurance, flexibility, frequency, duration and intensity) was evaluated using a self-report physical activity questionnaire. RESULTS: Male SI individuals were able to maintain steady state at the prescribed heart rate range while pushing a greater average resistance (SI: 3.38 ± 0.26 and VI: 2.49 ± 0.12 Kg) and at a higher average power (SI: 169.32 ± 13.20 and VI: 124.58 ± 6.25) than the VI individuals (p <0.05). Absolute VO2max estimate was higher for male SI individuals (SI: 3.77 ± 0.26 and VI: 2.88 ± 0.18 L/min). However, relative VO2max was not significantly different (SI: 42.78 ± 2.23 and VI: 41.00 ± 3.20 ml/ kg/min). Female SI individuals completed more curl-ups (SI: 52.50 ± 8.36 and VI: 25.64 ± 8.29), had a lower percentage body fat (SI: 31.78 ± 1.69 and VI: 36.95 ± 1.76) and higher absolute VO2max estimates (2.65 ± 0.13 & 1.93 ± 0.20 L/min) than their VI counterparts (p<0.05). Additionally, the SI females also had a higher (p<0.05) estimated relative VO2max (SI: 41.02 ± 3.86 and VI: 27.83 ± 2.75 ml/kg/min). There were no significant differences in self-report physical activity between the two groups for either gender. CONCLUSION: The VI males in this study have physical fitness levels similar to that of SI individuals. VI females had lower physical fitness levels than SI females. Further research is suggested to assess the need to develop programs specifically targeting female VI adults to improve and maintain physical fitness.

Socioeconomic differences in risk factors for obesity in adolescents in Northern Ireland

OBJECTIVES. To test for socioeconomic differences in some biological and behavioral risk factors for obesity in a representative and contemporary sample of adolescents. Cohort study of 2 016 randomly selected 12- and 15-year-olds representative of Northern Ireland, studied in 2000. We tested for differences in obesity risk factors based on a priori hypotheses between adolescents from affluent (n=487) versus deprived (n=237) families. Potential risk factors were dietary energy and macronutrient intake, habitual physical activity, TV viewing and computer use, and physical fitness. Adolescents of higher socioeconomic status reported significantly lower habitual energy intake (210 kJ/kg/d SD 80 vs. 229 kJ/kg/d SD 91, p < 0.01); significantly higher levels of habitual physical activity (physical activity score 25.9 SD 16.6 vs. 20.9 SD 16.4, p < 0.001), and had significantly higher cardiorespiratory fitness (estimated VO2 max 46.2 ml/kg/min SD 8.4 vs. 43.4 ml/kg/min SD 8.3, p < 0.001). Prevalence of overweight and obesity (BMI >85th percentile) in the cohort was 29.1% and was slightly but not significantly higher in the low (33.8%) versus the high (28.5%) socioeconomic groups. Differences in some of the biological and behavioral risk factors for obesity exist between adolescents of different socioeconomic status in Northern Ireland. These may help explain the basis of established socioeconomic differences in obesity risk.

Development of a Submaximal Test to Predict Elliptical Cross-Trainer &amp;Vdot;o2max

The purpose of this study was to develop an equation to predict VO2max from a submaximal elliptical cross-trainer test. Fifty-four apparently healthy subjects (25 men and 29 women, mean +/- SD age: 29.5 +/- 7.1 years, height: 173.3 +/- 12.6 cm, weight: 72.3 +/- 7.9 kg, percent body fat: 17.3 +/- 5.0%, and elliptical cross-trainer VO2max: 43.9 +/- 7.2 ml x kg(-1) x min(-1)) participated in the study and were randomly assigned to an original sample group (n = 40) and a cross-validation group (n = 14). Each subject completed an elliptical cross-trainer submaximal (3 5-minute submaximal stages) and a VO2max test on the same day, with a 15-minute rest period in between. Stepwise multiple regression analyses were used to develop an equation for estimating elliptical cross-trainer VO2max from the data of the original sample group. The accuracy of the equation was tested by using data from the cross-validation group. Because there was no shrinkage in R2 between the original sample group and the cross-validation group, data were combined in the final prediction equation (R2 = 0.732, standard error of the estimate = 3.91 ml x kg(-1) x min(-1), p < 0.05): VO2max = 73.676 + 7.383(gender) - 0.317(weight) + 0.003957(age x cadence) - 0.006452(age x heart rate at stage 2). The correlation coefficient between the predicted and measured VO2max values was r = 0.86. Dependent t-tests resulted in no significant differences (p > 0.05) between predicted (43.8 ml x kg(-1) x min(-1)) and measured (43.9 ml x kg(-1) x min(-1)) VO2max measurements. Results indicate that the protocol and equation developed in the current study can be used by exercise professionals to provide acceptably accurate estimates of VO2max in non-laboratory-based settings.