Originally posted by TiMan
Lately I am having a hard time reaching my target heart rate for Lactate threshold training and intervals. My effort is high but my heart rate is lower than normal....whats up with this? It seems that my maximum heart rate has dropped making for a lower heart rate at all intensity levels.
Thanx
Assuming that by "lactate threshold training" you actually mean time trial effort, then the HR that is associated with time trial effort/power can vary quite significantly on various factors (e.g., acute fatigue, chronic fatigue, anxiety, environmental conditions, cadence, topography, caffeine ingestion, etc).
For instance when i complete my TT power sessions, my HR can vary by up to 20 b/min, even though the power that i'm producing is the same. Thus, some weeks, my average HR during the interval is ~ 165 b/min and other weeks is ~ 185 b/min.
At virtually all intensities, it's preferable to prescribe training by power output as opposed to HR. This is due to variations in HR at a given workload (power output).
Perceived exertion is also an excellent measure, and you describe that your effort is high, and i assume that it feels the same as when your HR is 'normal'? This suggests that you're training at the correct effort, but your HR is depressed.
If your power is the same or higher (you won't know if you don't have a power meter), and your HR has changed then this is nothing to worry about. On the other, if your power and HR is depressed then this suggests that initially you are too fatigued and need some recovery. In fact, even if only your power is depressed then you need to ease up. One of the signs of overtraining is a decrease in performance.
As you get fitter your HR max *decreases*, but in a *recovered* state your average HR at TT power increases or stays the same.
Lactate threshold is actually quite a low intensity, usually sustainable for up to several plus hours in trained cyclists. It's usually determined as the workload (power output in cyclists, speed in runners) that elicits a 1mmol/L increase in lactate over exercise baseline levels (which would often be around 2 mmol/L) or at a fixed level of 2.5 mmol/L.
The effort that is associated with say a 1-hr TT is usually about ~20 to 25% higher than LT.