“Threshold power?” you say. “What is that?” Well, it is nothing mysterious, but it is something that is ultra useful for training. That is the highest power or effort that you can sustain for a prolonged period of time, such as 30 minutes.
Biologically, it is very closely related to your lactic acid threshold. When your muscles are working hard, they produce lactic acid, and the blood circulating through the muscles continually removes it. If you are working at a very hard pace, however, the rate at which lactic acid is removed can’t keep up with the rate of production and it starts building up in the muscle. That’s when you go anaerobic, your legs start feeling like blocks of lead, and you can’t keep that effort for much longer than a minute. Well below your threshold, you are fully aerobic, but you are not putting in the highest effort that you can sustain.
Well, you may say, I understand the concept of the power and lactate threshold, but how does it help my training, and how do I measure it?
Threshold power (TP) turns out to be extremely beneficial for setting power zones in training. It is decades old knowledge, and one that is religiously practiced by pros, that any good training program includes easy days, tempo days, interval days, and long days. Mix these up with some cyclic regularity and your fitness is guaranteed to improve. The problem is, how does an athlete know what is “easy”, or “tempo”, or a true “interval”? Sometimes we start out too fast, sometimes we still have a lot in the tank at the end of an interval, and it just doesn’t feel like we are doing it right. This is where threshold power comes to the rescue like a good friend.
Once you know your cycling threshold power, every other effort is defined in relation to that. You want to ride in your endurance building zone? Just don’t exceed 75% of threshold. You want short, power-boosting intervals? Do 2 minute repeats at 105% of your TP. Simple as that, with numbers to guide you.
Threshold power is unique to the athlete — in fact, it keeps on improving significantly with training. So every so often, and before starting a power training plan, you want to perform a simple test to measure your TP. Here are the steps.
To perform the test, you will need to pick a relatively flat, uninterrupted 10 mile stretch of road, preferably without stop lights or signals. The procedure for this test comprises the following steps:
1. Turn on the PowerEdge cycling app and select your user profile
2. Choose “Log a Ride” but do not press the “Start” button on the main ride screen
3. Warm up 15 minutes easy on a flat road
4. Press “Start” to begin your testing segment, which will record your power data
5. Ride at a sustainable, consistent, hard pace for 30 minutes or 10 miles, whichever comes first
6. Press “End” at the end of the test segment to complete your ride
7. Cool down for 15 minutes
8. Review your ride, taking note of your average power for the test segment. You may do this on your phone or by analyzing the ride file on a power training software or website. The average power for the test segment is your threshold power.
Note: If you are a beginner, decrease your warm-up and cool-down to 10 minutes and the test segment to 5 miles. As your fitness and ride distance improves, you can repeat the test at any time and increase the duration to the one above.
That’s it! Now you know your TP and are ready to tackle any power training plan! Happy riding!