top of page

To get faster slow down



There is no “one intensity fits all” workout. Slower, easier runs build aerobic base and recovery, while harder speed workouts and intervals are made to push our max heart rate and provide us with the ability to hold a higher intensity for longer.


Coaches talk about this a lot: don’t race your workouts. The athletes I am coaching often ask me the same question: “Is it fine if I run faster on days I really feel good?” The reply is no and here is the reason why.


Running easy builds our aerobic capacity (i.e., our capacity to extract oxygen and use it to feed our muscles). Slowing down is building our aerobic system enabling our body to give blood to our muscles more efficiently (our heart pumps more blood, our ventilation rate improves, our body builds new capillaries to carry more oxygen to our muscles). Our running efficiency and performance depend on our capacity to absorb oxygen and carry it to our muscles. Most of us take more oxygen than we can actually use and this is what we want to improve.


If we train even a little too hard all the time, even when it feels good, we are reaching a higher level of fatigue and this is affecting our hormones, cortisol (stress hormone) level and nervous system: this is why we are getting slower. Our best quality runs are those less glamorous, easy and slow, they make us run faster during races.


Now, running slow doesn’t mean jogging. We have to learn how to control our pace and running intensity. The tips I want to share with you today will give you an idea about how to control your training intensity. This is especially relevant when it involves female athletes.


How to monitor your training?


Am I too slow or too fast? It is not easy to understand how we should pace ourselves. Most runners use metrics such as pace and/or heart rate to determine effort. I am rarely using paces to monitor my athletes’ training.


Controlling our running intensity often goes with the standard heart rate training zones and the calculation of maximum heart rate to define each training zone. My own experience and research as an athlete and coach taught me to take those numbers with caution. It requires a very detailed lab analysis to estimate our maximum heart rate under various scientific protocols and the results are still approximative. Our maximum heart rate is also evolving, it is not a fixed number we can rely on forever. Age, fitness level and other factors are interfering with those numbers. There are also so many variables influencing our heart rate data from our daily life stress, fatigue, hormones for female athletes (our heart rate can increase during certain phases of our menstrual cycles, before ovulation and during our premenstrual phase).


The training method I am using with my athletes is more personalised and obtained without laboratory testing, mixing various training monitoring techniques:


1. Phil Maffetone’s training heart rate formula


Phil Maffetone’s formula to find the training heart rate we can use to monitor low to moderate intensity workouts is easy to calculate: subtract your age from 180 (bpm). If you are recovering from illness or overtrained, subtract another 5 points. For example, if you are a 30 years old athlete running consistently and without illness, then your training heart rate will be under 150bpm. If you are currently recovering from an illness, then your training heart rate will be 145bpm.


2. Lactate threshold heart rate


Find your lactate threshold and let it guide your workout. Find the workout intensity causing a fast accumulation of lactate in your blood (faster than the body can get rid of) to define the border between low and high intensity workouts. This is a better tool to monitor our efforts than the maximum heart rate and we can measure it regularly to check the progression.


Test your lactate threshold simply: run a 30min hard workout and use the average heart rate of the last 10min to calculate the intensity of your easy run.


3. Rate of perceived effort (RPE)


This is your own record about how difficult physically and mentally the effort feels for you. It helps track performance without fancy tech gears. Setting a specific RPE for a workout helps us to take into account external factors such as nutrition, hydration, lack of sleep, stress that are affecting our training. Let’s keep in mind that those factors are affecting our training sessions, making our body work harder. I am using it to learn how to adjust my workouts and avoid overdoing it.


Estimating your RPE is highly subjective. Strava has introduced a perceived exertion tool to help runners track this:


  • Easy (1-3): Could talk normally, breathing naturally, felt very comfortable

  • Moderate (4-6): Could talk in short spurts, breathing more labored, within your comfort zone but working

  • Hard (7-9): Could barely talk, breathing heavily, outside your comfort one

  • Max effort (10): At your physical limit or past it, gasping for breath, couldn’t talk/could barely remember your name


While a coach won’t base a training program solely on RPE, I am alway asking my athletes to pay attention to their RPE during their workouts. This is teaching us how to “feel the pace”. The more you take note of your effort level, the better you will accurately guess it and the less likely you are to push yourself too hard.


I am also using it to ensure that my athletes are not overtrained. If the same workouts are actually starting to feel harder, that increased RPE may be a sign of overtraining and we can adjust the training.


Like pace and heart rate, RPE is just another instrument in a runner’s toolbox to remind us to “feel our body” and not just rely on our GPS and tech gears. Data is too often imperfect and this can negatively impact our training. I really encourage athletes to also learn how to run by feel like I always did in both triathlon and running training, because solid training is about the big picture, not just the data.


Coach Carole

Run in Process Coaching founder & coach

Former professional triathlete and runner





0 comments
bottom of page