| 1. |
- Wergel-Kolmert, Ulla, et al.
(author)
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Repeatability of measurements of oxygen consumption, heart rate and Borg's scale in men during ergometer cycling.
- 2002
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In: Clinical Physiology and Functional Imaging. - 1475-0961. ; 22:4, s. 261-265
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Journal article (peer-reviewed)abstract
- The coefficient of repeatability (COR), expressed as 2-SD of differences, was calculated between two measurements of oxygen consumption (V O2), heart rate (HR) and rating of perceived exertion (RPE) during ergometer cycling by men. The two sets of measurements were performed 5 to 6 weeks apart. Nineteen healthy men performed an incremental maximal exercise test on an ergometer cycle. The load started at 50 W and increased by 5 W 20 s-1 until exhaustion was reached. At 40% of the individual maximum load of the pretest, the load was kept constant for 4 min in order to reach steady state. Gas measurements were recorded continuously by computerized instrumentation. The HR was monitored with electrocardiography (ECG) and the perceived exertion was evaluated using Borg's scale. The COR of V O2 at sub-maximal load was 14% and at maximum load 11%. The values in absolute figures were 209 and 332 ml min-1. The corresponding COR of the HR was 16% at sub-maximum load and 6% at maximum load, and an evaluation of the perceived exertion yielded CORs in absolute values of 4.8 and 1.3, respectively. The COR for V O2, HR and ratings of perceived exertion when cycling on an ergometer cycle thus indicate a better agreement between the measurements at maximum load. The COR of the heart at sub-maximal loads must be kept in mind when using HR for estimation of V O2max. The reported findings should be considered when using tests on an ergometer cycle for evaluating exercise capacity.
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| 2. |
- Wisén, Anita, et al.
(author)
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A novel rating scale to predict maximal exercise capacity.
- 2002
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In: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 87:4-5, s. 350-357
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Journal article (peer-reviewed)abstract
- To predict maximal exercise capacity, we have developed the rating of perceived capacity (RPC) scale, based on metabolic equivalents (METs). MET values from 1 to 20 were listed on a progressive scale and linked to physical activities. Test subjects rated their perceived capacity by choosing the most strenuous activity and the corresponding MET value that they could sustain for 30 min. In order to validate the RPC, 87 healthy women participated in the study (age range 21–79 years). The capacity rated from the scale (METRPC) was compared with the actual work capacity in a maximal incremental ramp cycle test. The maximal load achieved at the cycle test (in W), was transformed into the unit MET (METtest). The mean difference between METRPC and METtest was –1.4 (3.18) (2SD). Multiple linear regression showed that METtest depended significantly on METRPC and age. Extended regression analysis suggested that a nonlinear correction was most appropriate in order to improve the prediction. The maximal predicted capacity was given by: METpred=(5.08+0.70·METRPC)/[1+(e0.059 (age–87.2))]. After this correction, the mean difference between METpred and METtest was reduced to 0.0 (2.62) (2SD). Reference values for METpred and METtest were also obtained. In conclusion, the RPC combined with an age correction was shown to predict accurately maximal exercise capacity; it is also quick and easy to use. Thus, RPC may be a valuable tool in the prescription of exercise and in monitoring the effects of exercise and rehabilitation.
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| 3. |
- Wisén, Anita, et al.
(author)
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A refined technique for determining the respiratory gas exchange responses to anaerobic metabolism during progressive exercise - repeatability in a group of healthy men.
- 2004
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In: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 24:1, s. 1-9
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Journal article (peer-reviewed)abstract
- The respiratory gas exchange and ventilation during an incremental cycle exercise test were analysed in a group of 19 healthy, moderately fit men. Different computer algorithms were used to estimate the VO2 values where: (i) the rate of VCO2 increase just exceeds the rate of VO2 increase (DX, derivative crossing), (ii) VCO2/VO2 = 1·00 (PX, point of crossing) and (iii) ventilation (VE) increases disproportionately in relation to VCO2 (PQ, point of VCO2 equivalent rise). The DX and PQ measurements were analysed using a new approach employing polynomial regression and the value of PX was determined following low-pass filtration of raw data. The repeatability of the measurements was evaluated with a 5-6 week interval between the tests. The correlations between tests were 0·75 at DX, 0·85 at PX and 0·62 at PQ. The mean differences between the repeated tests were not statistically significant. The repeatability of VO2, in absolute values expressed as ±2 SD of the differences between the tests, had values of 5·0, 6·1 and 9·5 ml min-1 kg-1 for DX, PX and PQ, respectively. The mean value of VO2 for each measurement point expressed as a percentage of VO2max was 54% at DX, 68% at PX and 70% at PQ. The most common sequence of the measured values was DX < PX < PQ, but the sequence DX < PQ < PX was also observed. It is concluded that the gas exchange responses to developing anaerobic metabolism during progressive exercise can be characterized by a series of thresholds. However, the considerable variation in absolute values in the two testing occasions requires further attention.
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| 4. |
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| 5. |
- Wisén, Anita, et al.
(author)
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Arbetsprov på gångmatta
- 2003
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In: Det kliniska arbetsprovet. - 9144028490 ; , s. 96-96
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Book chapter (other academic/artistic)
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| 6. |
- Wisén, Anita
(author)
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Assessment of Aerobic Capacity A Novel Rating Scale and Further Development of an Exercise Test including Analysis of Gas Exchange
- 2004
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Doctoral thesis (other academic/artistic)abstract
- Different methods are proposed to assess the aerobic capacity. A novel scale, rating of perceived capacity (RPC) based on metabolic equivalents (METs) from 1 to 20, is presented. Selected MET values are linked to physical activities. Comparison of the rating with an exercise test in a group of women revealed that a correction based on age more accurately predicted the maximal exercise capacity. An incremental exercise test, including a constant work rate for four minutes, was introduced and combined with breath-by-breath measurements of gas exchange. Data collected every ten seconds were digitally filtered to determine selected variables. Fits of polynomials were utilised to determine the increasing contribution of the anaerobic metabolism, reflected by V'CO2, at three different thresholds. Equations were utilised to assess the time constant of V'O2 (Tau V'O2) (reflecting the time required to reach steady state) and the change in V'O2 corresponding to a specific change in work rate (delta V'O2/delta W). The repeatability of measures of the aerobic capacity (V'O2max, the three thresholds, V' O2 and delta V' O2/delta W) and of variables at rest, at sub-maximal and maximal levels was investigated. Considerable variations were found, which could mainly be explained by biological variation. Reference values for aerobic capacity were generated based on values from 25 healthy women (22–44 years) at low or moderate activity levels, and 41 healthy men (18–48 years) at moderate capacity. The results show that several variables and parameters can be determined in a single exercise test, which together describe the aerobic profile in a comprehensive manner.
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| 7. |
- Wisén, Anita, et al.
(author)
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Determination of both the time constant of vO and DeltavO/DeltaW from a single incremental exercise test: validation and repeatability.
- 2004
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In: Clinical Physiology and Functional Imaging. - 1475-0961. ; 24:5, s. 257-265
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Journal article (peer-reviewed)abstract
- A single incremental cycle exercise test including a steady-state load, combined with respiratory gas exchange, was performed with the objective of determining the time constant (o2) and the amount of oxygen required at each load (o2/DeltaW) by using a novel equation. The protocol was validated using four exercise tests at different constant loads and conventionally fitted mono-exponential functions to determine o2, and interpolation of o2 versus load to determine o2/DeltaW. No significant differences were seen between the means of either o2 or o2/DeltaW determined with the two protocols. The correlation coefficient was 0·62 for o2 and 0·48 for o2/DeltaW. The absolute differences (2 SD) were 11·6 s for o2 and 1·1 ml min-1 W-1 for o2/DeltaW. The equations were compared in the same steady-state test and good agreement of o2 was obtained (R = 0·99). The 5-6-week repeatability (incremental test) was evaluated. No statistical differences were seen between the mean of the repeated tests. The difference between the tests (2 SD) were 20 s for o2 and 1·2 ml min-1 W-1 for o2/DeltaW. In conclusion, o2 and o2/DeltaW can be determined from a single incremental test. The validation showed an acceptable agreement, although the variations in absolute values were not negligible. This could partly be explained by the natural day-to-day variation and fluctuations in incoming raw data. The test-retest variation in absolute values was considerable, which must be taken into account when using o2 and o2/DeltaW for evaluation of aerobic function.
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