Whether you're a beginner runner and you're just starting to prepare for your first 5k, 10k, or half marathon, or you're an advanced runner looking to set a PB and qualify for a monumental race like the Boston Marathon, Interval running is a crucial aspect of a training plan that will allow you to reach your goals.
What holds most runners back is that they don't run easy enough on their easy days, and they don't run with enough of the proper structure of their fast interval run days.
This post will fix that for you and get you what you need to reach your next running race feeling confident.
In this article, you'll learn:
- What is interval running vs. steady state running
- What are the benefits of interval running
- How to get started interval running
- What pace should your intervals be run at
- How often should you do interval running
- What are some interval running workouts
- How to stay safe and injury free while doing interval running
What is Interval Running?
Interval running, also known as HIIT (high-intensity interval training), fartlek running, hill running, or sprint interval training, is a type of cardio exercise that alternates periods of high-intensity effort with periods of rest or low-intensity effort.
This type of running is highly effective for burning fat, increasing endurance, and improving overall fitness levels. It's also a great way to break up the monotony of steady-state running and add some variety to your workout routine.
In our app, we refer to a once-weekly workout that encompasses all variations of interval running as the "Intense Run" because it is designed to create a well-rounded athlete. This workout includes different variations of HIIT, fartlek running, hill running, and sprint intervals, ensuring that you are working out your whole body, and targeting all of your important muscle groups.
Interval Running vs. Steady State Running
Interval running differs from steady-state running in that it requires you to push yourself harder and faster for shorter periods of time, mixed with periods of low intensity rest intervals. Instead of maintaining a steady pace for a long time, you'll run at your maximum effort for between 15 seconds to 30 minutes, followed by a period low-intensity effort or rest.
5 Key Benefits of Interval Training Workouts
Interval running offers many benefits, including improved cardiovascular fitness, increased calorie burn, improved endurance, speed and power, and higher pain tolerance. We'll outline the five main benefits here:
Benefit #1: Higher Cardiorespiratory fitness. One study found that more cardiorespiratory fitness was significantly correlated with a longer lifespan. By incorporating interval running into your workout routine, you will improve your overall fitness and increase your expected lifespan.
Benefit #2: Burn more calories. Interval running is excellent for burning calories because you're working harder. Your body will burn more calories during intervals than during lower intensity steady-state running.
However, when it comes to Super High Intensity Interval Training (SHIIT), athletes burn even more calories. SHIIT intervals continue to burn calories even after a workout due to an effect called post-exercise oxygen consumption.
Benefit #3: Build endurance. Even though interval running is not specifically an endurance-building workout, it can still improve your endurance. Interval running allows for the function of your mitochondria to improve so you'll be able to produce more oxygen and run longer.
Benefit #4: Improved speed and power. Interval running most obviously builds your speed and power, which can help you perform better in your races. You'll be able to run faster and longer, making it easier to achieve your running goals.
Benefit #5: Higher pain tolerance. Finally, interval running can also increase your pain tolerance. When you push yourself harder and faster, you'll be able to tolerate a higher level of discomfort, which will be important when you start taking on endurance challenges.
The Science Behind How Interval Running Works
Three key things happen in your body when you perform interval sessions:
- Your body has a hermetic response that causes adaptations
- Your body increases VO2 Max to process more oxygen
- Your body learns how to process lactate, so you don't build up lactic acid
A hermetic response refers to the body's adaptation to stress or strain through changes in physiology and anatomy. It is a physiological response to a stimulus such as exercise, that causes the body to adapt and become stronger or more efficient.
In the context of interval running, the hermetic response is the body's response to the stress of pushing harder and faster than what is comfortable. This leads to adaptations such as increased cardiovascular fitness, improved endurance, and increased speed and power.
Increased VO2 Max
Mitochondria are the powerhouses of the cell. They are responsible for producing all your energy through ATP. When you engage in low-intensity exercise, the mitochondria in your muscles will increase in number and density through mitochondrial biogenesis. While low-intensity running builds mitochondrial density, high-intensity running teaches those mitochondria how to function more efficiently.
High mitochondrial density in your muscles, particularly a high amount of mitochondria trained to function well, will result in a higher VO2 Max (the maximum amount of oxygen an athlete can process each minute). This study found that a high VO2 Max is very strongly associated with successful endurance racing.
High-intensity interval running, particularly intervals of 2-8 minutes, is the best way to make your mitochondria function at a high level and increase your VO2 Max.
Buffer Lactic Acid
Interval runs can also increase the ability to buffer lactate in the body. Lactate is a byproduct of exercise that can build up in the muscles and cause fatigue. When you're able to buffer lactate more effectively, you won't build up as much lactic acid and you'll be able to run faster for longer.
Different Types of Interval Runs Explained
There are several types of interval running, each with its own unique benefits.
- FARTLEK RUNS: Also known as "speed play," fartlek is a type of interval running that involves alternating periods of fast running with periods of slow, lower intensity or moderate running. These runs are less structured than the other following types of interval runs.
- SUPER HIGH-INTENSITY INTERVAL TRAINING (SHIIT): This is a type of interval running that involves very short, intense bursts going all-out for 15-60 seconds with 1-4 minutes of rest between intervals. These intervals are focused on creating top-end neuromuscular power and speed.
- HILL SPRINTS: These are similar to SHIIT by design, but they recruit more muscle groups and build a lot of explosive power. This allows you to bound off the ground more forcefully and improve running performance.
- VO2 MAX INTERVALS: These are intervals of 2-8 minutes and will increase the amount of oxygen you can process each minute. Rest intervals are 1-4 minutes. This type of training will improve cardiovascular fitness, endurance and overall running performance.
- TEMPO RUNNING: Tempo runs are interval workouts but tend to be in their own classification because they're 10-60 minutes long. This type of interval training will improve the ability to run at a steady pace for an extended period and help you maintain a consistent pace during a race.
Getting Started with Interval Running Workouts
Interval running is obviously a great way to improve your running performance, but it can be intimidating to get started if you're new to running. Here are the steps to get started:
Step 1: Determining Your Run Training Paces
The first step is calculating your pace zones. This can be done by performing a running time trial of 3 kilometers (1.86 miles) on a rest week. This will give you a good baseline for your current running abilities and help you create a training plan that includes interval running.
Below is a workout that athletes who use our app perform once every 2-4 months to keep their personal paces up to date. You can perform the folowing workout on your own, ideally during a rest week (this is a screenshot of the workout in our app).
Step 2: Create Interval Running Workouts
Once you have your training zone paces, you can create a training plan that includes your interval workouts. Start with short intervals of 15-60 seconds in your Zone 5 pace with long rest intervals of 1-4 minutes. This will help you get used to the intensity of interval running.
As you start to get more comfortable, make the intervals longer and the rest periods shorter. This will help you build endurance and stamina.
As you progress into longer intervals, you'll likely have to do them at your Zone 4 running pace. This will help you build speed and power.
Below are several example interval run workouts from the different training plans in our app so you can see what an interval running workout looks like. Perform just one interval run each week in your training plan.
- Super intense hills to create top end power and speed
- 1-3 minute intervals to get comfortable with longer intervals at the start of a training plan
- 4-8 minute intervals towards the end of a training plan with short rest to really increase VO2 Max and build endurance paired with speed
Here are a couple of examples from our app:
Step 3: Monitor Your Progress
It's essential to perform a new running time trial every 2-4 months to make sure your zone training paces are up to date. This will help you adjust your training plan as needed and continue to improve your running performance.
Safety Tips for Interval Training Running
Interval running is the single most likely place an endurance athlete will get injured, so we have to stress how important it is to take proper precautions for staying safe while training. Here are some safety tips to keep in mind:
- Never skip a warm-up that includes dynamic stretches and hip activations before getting into the intervals. A proper warm-up will help prepare your body for the intense effort of interval running and prevent injuries.
- Never run with old running shoes or shoes you wore to run the day before. You want to make sure your shoes have as much cushion as possible to perform interval runs. Wearing old shoes or shoes that have been worn out can lead to injuries such as shin splints, blisters or other types of injuries.
- Listen to your body and avoid overtraining. Be very conscious of niggles and other early signs of injury. If you're feeling twinges that don't feel better after a warm-up, or if you're sore for two days or more after a run, you need to back off from interval running.
- Gradually build up every aspect of interval runs, starting with just a few minutes each week. Start with short intervals every time you start working on something new. For example, even if you're well adapted to interval running, don't just go and start performing hill sprints without slowly building up with just a few minutes a week.
One of the biggest things you have to understand about interval runs is that your heart and lungs will adapt to the intensity of interval running very quickly, and your fast runs will feel great. However, your musculoskeletal structure takes many months to adapt to the harsh forces of running. So it's really wise to ease into all aspects of interval running gradually, or you'll almost certainly be inviting injury.
Wrap-Up on Beginner Interval Training
Without properly designed interval runs, it will be difficult for any runner to make progress. Low intensity runs build the foundation of run fitness, while high intensity interval running is the training that turns the work into a house.
Fortunately, you've now got the basics of incorporating interval running into your workout plan safely and effectively.
Of course, understanding all the ins and outs of implementing what you've learned into a training plan can be intimidating. If you want a personalized training plan designed specifically to help ordinary people accomplish extraordinary things in endurance sports, check out our app here.