Rather than having a single weight and a single resting and maximum heart rate, as of today, these numbers now have dates associated with them, so an entire history of them can be stored. They can be shown on a chart too:

Charts appear on the FTP, heart rate and weight pages when there are more than five of the relevant value.

This is useful for people who measure their resting heart rate frequently (a higher than normal resting heart rate often occurs when overtraining), and also for those who want to keep track of their weight.

This also means that these three parameters (weight, resting and maximum heart rate) are now treated in conceptually the same way that FTP is — they’re histories of a value, and provided at least one value exists, the value for any day can be given according to the following rules:

• If the date is before any entries, the value of the first entry is given.
• The value of the most recent entry on or before the date is given. No interpolation is ever done, and this is why the chart above looks “stepped”.

Finally, this also means that FTP, weight, resting and maximum heart rate have a consistent interface on the API that is being developed. Let me know if you want early access to it.