That alphabet-soup title translates to Lactate Threshold Heart Rate Time Trial, for those in the know. Here's a 60-minute workout that will help you approximate your LTHR for the bike (keep in mind it will be different on the run, and LTHR isn't an accurate measure to use in the pool). You can also use this workout to estimate your functional threshold power (FTP), if you have access to a power meter. There's a 20-minute warm-up to get you ready for the time trial, and the time trial is 30 minutes long. You should go as hard as you can for those 30 minutes. If you're testing heart rate, hit the lap button 10 minutes into the time trial; your LTHR will be the average heart rate you sustain for the last 20 minutes of the time trial. If you're testing FTP, take the average for the whole 30 minutes (so you'll hit your lap button at the beginning of the time trial).
Click the link below to download the workout:
Spin & smile!