Why Running Slower Is Better For You

Total volume, intensity and variability are all important to consider if you want to maximise your fitness gains. As we get fitter and stronger it is exciting to run fast and feel good doing it. There is temptation to keep pushing the pace until suddenly you are doing 4.30 min/KM on your long runs. While this may feel good short term and is certainly impressive this can cause more harm than good. These are some of the benefits of running at a slower pace

Maximising the aerobic energy system capacity

Any event that lasts longer than 2 minutes is going to be predominantly fueled by the aerobic energy system. So it is super important for performance that we maximise aerobic capacity and the only way to do this is by training below our aerobic threshold (AeT, a metabolic marker relating to blood lactate). If we are running too fast, the energy demands increase and we start to utilize more of our anaerobic energy systems. Long term training like this can result in Aerobic Deficiency Syndrome (ADS) and poorer performance.

Maximising total volume levels

Many runners tend to focus on pace and weekly KMs as a measure of how much running they do, after all saying you do 100 kms a week at 4:30 min/KM pace sounds more impressive. But KMs run is less important compared to the total volume of duration of weekly training. The cardiovascular system (heart and lungs) adapts to exercise based on the amount of time loading it, so the more minutes and hours you do the better. Doing 100kms at 4:30 pace will only be 7.5 hours of training for the week, but if you slow down to 6 min ks it will be 10 hours a week. AND if you slow down you will probably be able to increase your weekly KMs because your legs aren’t so tired!

Lower risk of injury

As our speed increases, so does the demand on all of the muscles and tendons in our legs and feet. They have to generate more force to increase stride length, increase the rate of force development to increase turn over AND have to absorb more load and ground reaction forces. This increase in load is good, great in fact, for increasing the tolerance of those tissues, but only when done gradually and not in every session. Too much too soon will result in overload of the muscles and tendons which do take longer to adapt compared to our fitness levels. If not addressed, this overload then turns into injury, time off running and overall reducing you fitness gains.

So how fast should we be running?

Using heart rate (HR) to determine intensity is the best way to set our training sessions and maximise the benefits of training. Once you have determined your different HR zones that will dictate your desired HR for a particular session and then you run at a pace that matches that HR. Keep in mind that this pace will fluctuate day to day depending on how you're feeling. This allows for more flexibility in training and means we are actually listening to the body's needs (super important!).

Alternately without a HR monitor you can also use the “Rating of Perceived Exertion” (RPE) scale with easy being 4-6 and hard being 7-10.

When setting out your running training you should be doing 80% of your running EASY in zone 1 and 2 and up to 20% doing intensity training in zone 3 and 4. BUT if you have ADS then you should be doing 100% of your training below the AET ( i.e zone 1 and 2) until you have maximised your aerobic capacity.

Learn more about HR zones and how to measure them in the next blog...