oxygen uptake () describes the rate at which oxygen is utilized by tissues (Burton et al, 2004).
is determined by heart rate (heart beats each minute), stroke volume (the volume of blood pumped from one ventricle each beat) and arteriovenous oxygen difference (difference in blood-oxygen content between arterial and venous blood).
Oxygen is needed for respiration, the chemical process that produces energy in the form of ATP.
Several sources agree that oxygen uptake increases linearly with exercise, this is due to the skeletal muscles requirement for more oxygen for the production of more ATP. Hanson et al (1998) measured continuously in 10 healthy participants during cycling exercise while varying the rate of work incrementation, they found oxygen uptake to increase linearly at low intensities but to a greater asymptote at higher intensities. The aim of this study was to analyze the effect of incremental submaximal exercise on and therefore determine whether there is a correlation between oxygen uptake and work rate. Method
The saddle height of the Monark peak 894 ergometer was adjusted according to the participant (Gender: Male, Age: 21), they were asked to breathe into the gas collection apparatus wearing a nose-clip in order to re-establish normal breathing during the trial. The participant was then asked to cycle for 16 minutes at 4 progressively higher exercise intensities, starting with 1. 5kg and going up in 0. 5kg increments, cycling continuously at 60 rpm throughout. Each interval lasted 4 minutes; in the last minute of each interval a one-minute sample of air was collected into one of the four prepared Douglas bags.
The Review on Predictive Maximal Oxygen Uptake Test
... dioxide you exhale versus the volume of oxygen you consume at a given exercise intensity. A lower RER means that you are ... a) collecting blood lactate concentration 4-5 minutes after exercise, (b) a final heart rate within 10beats.min-1 of the age predicted ... criteria have been used by scientists to characterise the oxygen uptake measured. BASES (1997) suggested additional criteria to assess whether ...
In addition, a rating of perceived excursion (RPE) was recorded by communicating an RPE chart in the final minute. Heart rate of the participant was recorded in 15s intervals. At each increment, 0. 5kg was applied to the flywheel to increase resistance. After the trial the four samples of expired air were analysed using a High-tech GIR250 gas analyser, first calculating the respective percentages of O2 and CO2, and then completely evacuating the Douglas bags to record the volume and temperature of each gas sample collected.
Gas volumes were corrected for standard temperature and pressure, dry (STPD); and were used to calculate . Data collected from the ergometer and incremental tests were then used to calculate work rate (W).
These values were plotted on a graph and tested using a one-tailed Pearson moment correlation statistical test. Results The results from the study showed that as work rate increased at each increment mean=29. 44W, also increases by mean=0. 33l. min-1. Increases in were slower between the 2nd and 3rd increments (0. 1l. in-1 increase) but it is evident from steeper gradients on the graph (figure 2) the greatest increases are at the beginning and end stages. The results of a one tailed Pearson correlation between and WR were N=4, r=0. 973, p=0. 008, a significant correlation. Table 1: Table showing work rate (W), Heart Rate (bpm) and (l. min-1) at each increment Intensity (kg)| Work Rate (W)| Heart Rate (bpm)| (l. min-1)| 1. 5| 88. 31| 95| 1. 7| 2| 117. 75| 119| 2. 1| 2. 5| 147. 18| 140| 2. 2| 3| 176. 62| 161| 2. 7| Figure 1: Scatter plot of work rate (W) versus (l. min-1) Discussion
Figure 1 shows an almost linear relationship between work rate and , in addition this is supported by the Pearson correlation test (r=0. 984) which implies that as work rate increases increases. These findings were expected because the results are consistent with previous research conducted by Asmussen et al (1965), Who used intervals of cycle ergometry at different intensities to find a linear relationship between work rate and steady-state oxygen uptake. For the participant in this trial to sustain 60rpm, their muscles must produce progressively more force after each increment, as 0. kg resistance is applied to the flywheel each time, therefore the energy demands of the muscle progressively increase. A deviation from the trend during the middle of the trial was not expected as most sources agree the relationship is linear (Burton, Ozyener, Glassford), however Astrand (1961) found a non-linear steeper increase in during the middle stages. Astrand’s non-linear pattern may be explained by production of power increasing to a point beyond the lactate threshold, the point at which lactic acid starts to accumulate in the blood.
The Essay on Interest Rate Increase Bank Rates
Objectives: Primary To successfully invest $200 m of funds into short term securities with the highest possible yield in order to maximise our return on profit. 10% of our funds are required to be invested in the overnight market and 50% should be available over the next 3 months. Secondary To speculate in the market according to interest rate movements over the next 6 months by buying and selling ...
A slowly developing increase in during constant-work-rate exercise performed above the lactate threshold produces a curvilinear relationship and is known as the slow component of kinetics (Jones et al, 2011).
The cause for the steep increase at the final stage of the trial is supported by the research of Bernard et al (1996), who measured the effects of increasing exercise intensities recording oxygen consumption and heart rate simultaneously. Findings revealed a significant correlation with the best predictions of from work rate observed at higher intensities.
Bernard’s findings support results in table 1 that show the greatest increase in both heart rate (+30bpm) and oxygen composition (+0. 5 l. min-1) to be during the final increment and therefore highest exercise intensity. Deviation from the trend during the 2nd and 3rd stages of the trial could be a result of the participant getting familiar with the exercise. To improve the reliability of future studies a larger sample of participants should be used.
Deviations from the trend could also be as a result of human errors; some volume could have been lost when attaching the Gas Analyser to the Douglas bag or if the one of the four Douglas bags was faulty. Considering the results of this study in addition to previous research, it is concluded that there is a strong correlation between and work rate however this may not necessarily be a completely linear relationship; so to investigate this smaller increments should be used in the study.
The Essay on Heart Rate Pressure Blood Exercise
Abstract The aim of the study was to investigate the effects exercise had on heart rate, systolic and diastolic blood pressure. The aim was to compare heart rate, systolic and diastolic blood pressure between lying supine and when cycling at 100 W intensity and to detect any significant differences. The group of subjects comprised 10 first year Sports Science male (n = 7) and female (n = 3) ...
