Im writing a step test program and im stuck with an equation

[robbiedarza]

Im writing a step test program to replace the current paper version, I need to calculate a persons aerobic capacity.

I take an athletes age and calculate his max heart rate: 220 - the athletes age.

I plot 5 heart rate readings (the y values) against the step height (the x values) and draw a line of best fit between these points, I then extend this line to cross their max heart line for their age and then drop a line from this intersection to the baseline and read the predicted aerobic capacity. I have calculated the slope and the y intercept and ive got it working so it gives me some correct values, but the part I am stuck on is how to get the aerobic capacity by extending the line to cross the max heart rate and dropping a line down to the x value to get the aerobic capacity. Its something to do with the max heart rate = slope x + the y - intercept (200 = -1x +14) ???? Im really stuck!

here is a link to the current paper version

< link to objectionable page removed >

here is a link to the document ive been given to calculate th eline of best fit https://drive.google.com/open?id=0BzRLgnigPJ-qS3EyNlBfei03ekk

I would be really greatful for any ideas please.

Thanks, Robbie.

 

[Deleted member 4993]

Im writing a step test program to replace the current paper version, I need to calculate a persons aerobic capacity.

I take an athletes age and calculate his max heart rate: 220 - the athletes age.

I plot 5 heart rate readings (the y values) against the step height (the x values) and draw a line of best fit between these points, I then extend this line to cross their max heart line for their age and then drop a line from this intersection to the baseline and read the predicted aerobic capacity. I have calculated the slope and the y intercept and ive got it working so it gives me some correct values, but the part I am stuck on is how to get the aerobic capacity by extending the line to cross the max heart rate and dropping a line down to the x value to get the aerobic capacity. Its something to do with the max heart rate = slope x + the y - intercept (200 = -1x +14) ???? Im really stuck!

here is a link to the current paper version <link removed>

here is a link to the document ive been given to calculate th eline of best fit https://drive.google.com/open?id=0BzRLgnigPJ-qS3EyNlBfei03ekk

I would be really greatful for any ideas please.

Thanks, Robbie.

You have the equation already!!

max_heart_rate = slope * x + the y_intercept

Where are you exactly stuck? This is an equation of a straight line. Do you understand the parameters of this equation?