A tempo workout is a type of moderately hard, sustained effort performed in endurance training, sitting squarely between an easy aerobic pace and a maximum-effort interval pace. This specific level of intensity is often described by athletes as “comfortably hard.” The goal of incorporating this work into a training schedule is to teach the body to maintain a faster pace for a longer duration without prematurely fatiguing.
Defining the Lactate Threshold Goal
The purpose of a tempo workout is to improve the body’s ability to manage and clear a metabolic byproduct called lactate, which is directly tied to the concept of the Lactate Threshold (LT). This threshold represents the highest intensity an individual can sustain before lactate production rapidly exceeds the body’s capacity to clear it from the bloodstream. Once this clearance rate is overwhelmed, hydrogen ions accumulate, which contributes to the burning sensation and rapid onset of muscular fatigue. By training at this specific intensity, you are deliberately stressing the physiological system responsible for lactate clearance.
The body responds to this stress by becoming more efficient at buffering and recycling the lactate for use as fuel, effectively pushing the LT to a faster pace. This shift means that a pace that previously caused rapid fatigue will eventually become sustainable for a longer period. Tempo training is focused on increasing the speed or power output at which this tipping point occurs, allowing an athlete to run, cycle, or swim faster while remaining in a sustainable aerobic state. This is why the effort is sometimes referred to as threshold training.
Practical Execution and Pacing
A tempo effort is typically performed at a pace you could theoretically sustain for a race lasting between 50 and 70 minutes, which often correlates to a 10-kilometer or half-marathon pace for many runners. In terms of heart rate, the intensity generally falls between 80% and 90% of your maximum heart rate. This target zone ensures the body is working hard enough to stimulate the desired physiological adaptation without crossing into a zone that causes immediate burnout.
A simpler, more accessible method for gauging the correct intensity is the “talk test,” where the pace should allow you to speak only in short, broken phrases or single words. If you can speak in full sentences, the pace is too slow; conversely, if you cannot utter any words, the pace is too fast. The main work segment of a continuous tempo session usually lasts between 20 and 40 minutes, which is the time frame required to maximize the stimulus on the lactate clearing mechanisms. Incorporating one tempo session into a weekly training schedule is a common practice for athletes aiming to significantly boost their endurance capacity.
Continuous Versus Intermittent Formats
Tempo workouts are structured in two primary ways: the continuous format and the intermittent format. The Continuous Tempo involves maintaining the prescribed “comfortably hard” effort for the entire duration of the main set without any planned breaks. For example, this might be a single 30-minute block at the target pace, which is effective for developing the mental toughness required to sustain a difficult effort during a race. It also provides an uninterrupted stimulus to the cardiovascular system, mimicking the sustained effort of a competition.
The Intermittent Tempo, often referred to as tempo intervals or cruise intervals, breaks the total time at tempo pace into shorter, high-quality segments. This might involve three repetitions of 10 minutes at the target pace, separated by a brief, active recovery period, such as 60 to 90 seconds of light jogging. The short rest allows for a partial clearance of lactate, which enables the athlete to accumulate more total time at the desired intensity than they could in a single continuous block. This structure is particularly useful early in a training cycle or for athletes who find the sustained mental effort of a continuous tempo run too demanding.