(* treadmill.pas - Determine how many calories are burned on the treadmill.
 * We need the following numbers from the user:
 * Speed, incline, time, weight
 * Formula comes from
 * https://www.livestrong.com/article/34973-calculate-treadmill-calories
 *)
program treadmill;

var
  pounds, kg, mph, mpm, incline, minutes, oxygen, cpm, calories: real;

begin
  (* Input *)
  write('Enter your weight in pounds:  ');
  readln(pounds);
  
  write('How fast did you go (mph)?  ');
  readln(mph);
  
  write('What was the % incline?  ');
  readln(incline);
  
  write('How many minutes did you walk/run?  ');
  readln(minutes);
  
  (* Calculations:
   * Let's begin with the necessary unit conversions.
   * Convert speed to meters per minute, percent grade to a decimal,
   * and weight to kilos.
   *)
  mpm := 26.8 * mph;
  incline := incline / 100.0;
  kg := pounds / 2.2;
  
  (* Now we are ready for the oxygen formula:  ml per kg per minute.
   * It assumes 3.7 mph represents walking and uses a different for running.
   *)
  if mph <= 3.7 then
    oxygen := 0.1 * mpm + 1.8 * mpm * incline + 3.5
  else
    oxygen := 0.2 * mpm + 0.9 * mpm * incline + 3.5;
  
  (* Now calculate calories per minute, and the total calories. *)
  cpm := oxygen * kg / 200.0;
  calories := cpm * minutes;
  
  (* Output.  Precede the output with an empty writeln to visually
   * separate the input from output.
   *)
  writeln();
  writeln('Your speed was ', mpm, ' meters per minute.');
  writeln('You consumed ', oxygen, ' ml of oxygen per kg per minute.');
  writeln('You burned ', cpm, ' calories per minute.');
  writeln('Finally, you burned ', calories, ' calories.');
  
end.