It’s the question all runners want to know – “how long will it be before I see the benefits from my workout?” Unfortunately, like most aspects of running and training, there isn’t a quick and easy answer.

Most experienced runners have heard that it takes 10 days to realize the benefits of a workout. While I agree that this is a good rule of thumb to follow, especially during the taper phase of a training plan, it’s not a very accurate measurement of how your body responds and adapts to a myriad of different training factors. For example, the exact rate your body absorbs and responds to a workout is going to be influenced by the type of workout, the intensity, your recovery protocol, and your body’s own rate of adaptation.

However, while there is no universal and simple answer to this question, if we take the time to breakdown all the factors that affect workout absorption, you can extrapolate a fairly accurate estimation of how long it will take to benefit from each type of workout on your training schedule.

Setting the stage

Like any analysis that involves a myriad of influencing factors, the first thing we need to do is establish our assumptions and control some of the influencing variables.

First, for the purpose of this in-depth breakdown, we’re going to assume that you’re implementing a thorough recovery plan after each workout. While ideal workout recovery is an article in itself, we’ll simply presume that you’re at least doing three things after each workout: (1) fueling properly; (2) getting plenty of sleep; and (3) stretching or massaging to reduce soreness. Certainly, you can be doing more to speed your recovery, but this is the baseline we’ll use for general workout adaptations.

Second, we need to make an assumption about your general rate of recovery. It’s unfortunate, but some runners have the ability to recover faster than their peers. We all have that running pal who seems to bounce back from track workouts like she didn’t even run the day before (if you don’t know someone like this, then you’re the envy of all your running friends because you’re “that guy”). Likewise, runners generally recover slower as they get older. Typically, a 65-year old is going to take longer to recover from a hard workout than a spry runner in their mid-20’s. For the sake of keeping things simple, we’re going to assume your rate of recovery is about average for a 35 to 40-year old runner. If you’re older or have found that you recover much faster than your running peers, you’ll be closer to the outer numbers of the ranges presented below.

How long it will take to benefit from each type of workout

As mentioned previously, the type of workout you perform and the intensity at which you run it will determine how quickly you see benefits. Why? Because your cardio-respiratory, muscular, and nervous systems all respond to training at a different rate. Since each type of workout is designed to stress a particular physiological system, the rate of adaptation will vary.

To make it simple, here is how quickly you’ll reap the benefits from each type of workout on your training schedule:

Speed development

Speed development workouts target the nervous system and are designed to develop the communication between your brain and your muscles. More importantly, improvements to the nervous system allow your brain to activate a greater percentage of muscle fibers and fire them more forcefully.

Speed development workouts aren’t the type of speed work most runners think about. Instead of lung busting intervals, you’re doing short, full speed repetitions on full recovery. Examples of speed development workouts include explosive hill sprints, in-and-out 150’s, or 200m repeats with full recovery – the type of stuff you see sprinters do on the track.

Luckily, you can reap the benefits from a speed workout very quickly – within a day or two. The nervous system responds quickly to new stimuli because the growth and recovery cycle is very short – according to this study, it’s the same principle behind and extensive warm-up that involves dynamic stretching and strides. The nervous system responds very quickly to new stimuli and changes.

VO2max and hill work

VO2max and hill workouts are designed to develop your anaerobic capacity, or your ability to withstand a large amount of oxygen debt, and your muscular system.

Unfortunately, muscle strength and anaerobic capacity take longer to develop because of the intense demand on the body and the amount of time it takes for the muscle fibers to recover after intense sessions. Therefore, it takes anywhere from 10-14 days to realize the full benefit from an anaerobic capacity workout.

You should also note that because of the demanding nature of these workouts, you may actually feel like you’ve “lost fitness” for 7-8 days after these workouts. We all know running the day after an intense session of 400’s can be difficult, but the performance loss will carry through for a few extra days, so be wary.

Threshold runs

Threshold runs, tempo runs, and marathon pace runs are designed to train your body to increase its ability to reconvert lactate back into energy. In general, these types of workouts are taxing, but they aren’t slug fests like a VO2 max workout might be. Therefore, the recovery cycle after a tempo run is faster, which enables you to reap the benefits from the workout within 7-10 days.

Long runs

Finally, the goal of a long run is to build-up your aerobic system. Primarily, this is accomplished by increasing the number and size of the mitochondria in your muscle fibers, increasing the number of capillaries, and increasing the myoglobin content of your muscle fibers.

While these improvements to the aerobic system are great for long-term development, you don’t often “feel” the benefit from them right away. It can take 4 to 6 weeks to notice changes in your aerobic ability and for the actual training effect being felt. Likewise, the more experienced you are, the less you will “feel” the benefits from a long run since you aerobic system is already quite developed.

An easy to use chart

Here’s a quick and easy chart that breaks down the general timeframe it takes to realize the benefits from each particular workout:

Workout type Intensity/difficulty When you’ll see benefits Speed development Hard 1-3 days Medium 1-3 days VO2 max/Hills Hard 12-15 days Medium 9-11 days Threshold Hard 10-12 days Medium 7-10 days Long Run Hard or Medium 4-6 weeks

This chart makes it easy to see why a general 10-day rule is applied, but isn’t always an accurate assessment of when you’ll realize the benefits from a session.

Long-term benefits of training

It’s important to note that realizing the benefits from one workout and fully developing each energy system are two completely different training topics. In this article, I’ve merely outlined the time it takes for your body to repair the muscle damage and experience some amount of growth in a specific physiological system. Fully developing any of these energy systems takes time – and lots of it (years). However, long-term development is a topic that deserves its own article entirely – so stay tuned.

As a note, the understanding of this principle is how your coaches are able to accurately assign you workouts and when we know that it’s time to up the intensity. By knowing your current fitness, recovery rate, and running history, we can precisely predict when you’ll adapt to the training load and be ready for the next challenge.

A version of this post originally appeared at competitor.com