Context: Cadmium is an important predictor of lung function, including forced vital capacity, forced expiratory volume and peak flow. Current evidence supports the notion that cadmium may be an important risk factor for cardiovascular fitness. Objectives: The purpose of this study was to determine the effect of cadmium exposure on cardiovascular fitness in representative sample of US white, blacks and Mexican Americans. The study also sought to determine if the relationship between cadmium and cardiovascular fitness varies by gender and racial/ethnic group. Methods: The data utilized for this study were obtained from National Health and Nutrition Examination Survey (NHANES). One-thousand nine hundred and sixty three subjects with data on cardiovascular fitness were eligible for this investigation. In NHANES, cardiovascular measurements were taken in series consisting of two minutes warm up exercise, two-three minutes exercise testing and two minutes resting period .The goal was to elicit 75% of predetermined age-specific heart rate by the end of the stress test. Cadmium was measured in the laboratory by taking urine sample of participants. Gender and race/ethnic specific multivariate linear regression analyses were performed to determine relationship of urinary cadmium with VO2 max. Results: There were gender and racial/ethnic difference in the relationship between urinary cadmium and VO2 max. In males and females, increased concentration of urinary cadmium was associated with decreased VO2 max across racial/ethnic groups (except in black males. The greatest negative association between cadmium and VO2 max was observed in black females (beta=-0.330) while the lowest value was recorded for white females (Beta=-0.074). The association was statistically significant in white males (Beta=-0.402, P =0.020) and Mexican American females (Beta=-0.290, P=0.026). Conclusion: There was inverse association between urinary cadmium and estimated VO2 max in a US nationally representative sample of White, Black and Mexican Americans. The impact of the gender and racial/ethnic differences in the association between urinary cadmium and VO2 max is not clear and warrants further investigation.

Bakgrund: Det finns flertalet modeller av pulsklockor på marknaden med funktioner som skall kunna uppskatta individens maximala syreupptagningsförmåga. En av dessa modeller är Polar Vantage V, som enligt tillverkaren kan uppskatta individens VO2max genom funktionen”konditionstest”. Testet utförs genom ett fem minuters vilotest. Testvärdet beräknas sedan från hjärtfrekvens samt personliga faktorer. Syfte: Studien jämförde Polar Vantage V uppskattade testvärde med en direkt mätning av VO2max, med frågeställningen om detta test var pålitligt och användbart i praktiken. Metod: En experimentell studiedesign användes som inkluderade 11 män samt 5 kvinnor som deltagare (N=16). Alla deltagare utförde Polar Vantage V’s konditionstest i vila, för att sedan utföra en maximal prestation utfört på löpband. För mätning av VO2max användes ergospirometri-systemet Jaeger®Vyntus CPX med halvmask. Resultat:Kendall Tau-b test visade signifikant starkt positivt samband mellan Vantage V’s testvärde och VO2max från Vyntus CPX. Wilcoxon Signed Rank test visade ingen signifikant skillnad mellan testvärdet (grupp medelvärde) från Vantage V och Vyntus CPX. Slutsats: På grund av stora individuella skillnader i testvärdet mätt med ”Konditionstestet” från Vantage V, bör individen tolka resultatet med aktsamhet. Vantage V’s ”Konditionstest” verkar emellertid kunna ge en bra uppskattning av VO2max på gruppnivå för friska vuxna i 20-36 års ålder. / Background: There are several models of fitness devices on the market with functions that claims to have the capability to estimate the capacity of a individuals maximum oxygen uptake. One of these models is the Polar Vantage V fitness watch, which according to the manufacturer can estimate the VO2max through the function "Fitness test". The test is performed through a five-minute rest test. The test result is then calculated thru various variables such as the individuals resting heart rate and personal factors. Purpose: To assess the estimated test value of the Polar Vantage V “Fitness test” with a direct measurement of VO2max, with the research question whether this test was valid and useful in practice. Method: This study used an experimental design and included 11 men and 5 women as participants (N = 16). All participantsfirst performed the Polar Vantage V's “Fitness test”, then proceeded to perform a maximum performance using a treadmill. For measurement of VO2max, the cardiopulmonary exercisetesting system Jaeger®Vyntus CPX with half mask was used. Results: Kendall Tau-b test presented a significant strong positive relationship between Vantage V’s “Fitness test” and VO2max -value from the Vyntus CPX. The Wilcoxon Signed Rank test presented a nonsignificant difference between the test value (group mean value) from Vantage V “Fitness test”and VO2max from Vyntus CPX. Conclusion: Due to large individual differences in the test value measured by the "Fitness test" from Vantage V, one should interpret the test-result with care. However, the Vantage V "Fitness test" seems to be able to provide a good estimate of theVO2max at group level in healthy adults aged between 20-36.