Interval training is often assumed to be a form of vigorous aerobic exercise only suited to the fittest people. However, if you’re new to training and are building from a brisk walk to light jogging or want to boost your cardiovascular fitness and general endurance, interval training can be a fantastic stepping stone.

The basics are that interval training workouts are built around periods of high intensity, followed by recovery intervals, normally for the same amount of time. Think 30 seconds of running followed by 30 seconds of rest or walking – similar to a couch-to-5K programme.

Of course, those short intervals are entirely customisable, whether you can manage an all-out effort on an assault bike or rowing machine or need to start slowly and focus on a form of fitness training suited to you. Let’s look closer at interval training, why working out at an increased intensity is beneficial, and how I might adapt an interval training session to suit your fitness goals.

How Does Interval Training Work?

Interval training is designed around the concept of raising your heart rate through an appropriate form of high-intensity exercise, ramping up the speed or type of intensity you aim for as your fitness improves.

One of the great aspects of an interval training programme is that you can use any exercise or workout, depending on the available equipment, whether you’re training at home, in the gym or out and about, and any specific sport you play.

Interval workouts, for example, can be based on 30 seconds on, 30 seconds off, one to two minutes of running followed by two minutes of rest, or short bursts of effort for, say 20 seconds. They can also incorporate a huge array of movements, such as:

    • Tuck jumps, jumping jacks or burpees
    • Sprint training, such as ladders or uphill efforts
    • Shuttle runs, jogging or skipping
    • Cardio equipment, such as an exercise bike

By maintaining a consistently high heart rate but giving yourself room to recover, you can often exert more energy and work harder rather than trying to keep going for a longer period of time at a moderate effort level.

Variations on an Interval Training Programme

Trainers might use a few different terminologies, all of which refer to types of interval training workouts. These include HIIT (high-intensity interval training) and fartlek training – derived from the Swedish words for speed play.

HIIT is a form of interval training plan that involves working toward the upper end of your maximum heart rate. Most HIIT workouts aim to get your heart rate up to around 80%, or as sprint interval training based on your maximum VO2 – that’s the top rate of oxygen your body can use during a workout.

Fartlek training is an exercise approach designed by a Swedish Olympian to help elite athletes compete in middle and long-distance running races. The idea is similar to interval training but means your bursts of intense exercise are followed by recovery segments. Rather than short, sharp efforts, fartlek training is a continual training session with slower, longer intervals and rest periods in between.

Which is the best option for you? A lot depends on your fitness aspirations and the types of training, sports, or workouts you enjoy. Still, all of these techniques are comparable ways to make the most of your natural energy systems to harness all the health benefits they offer.

What Are the Benefits of Interval Training?

Interval training is a superb way to adjust your training if you’re already a regular gym-goer but have hit a plateau. It’s also a great option if you’re returning to exercise or are new to working out and want to make the most of limited time.

Rather than commanding an hour of training, intervals can be completed in as little as ten minutes without compromising on the outputs you achieve during this short period of activity.

Some of the headline advantages of incorporating interval training workouts into your routine include:

    • Improved heart health, with interval training often recommended as a proactive method of cardiovascular disease control. High-intensity training can augment your cardiorespiratory fitness faster and more effectively than medium-intensity exercise.
    • Reduced body fat – you can burn more calories during a shorter workout by pushing your speed or exertion during an interval training session. The magic is that your body continues burning calories long after your workout has ended while you recover.
    • Boosted endorphins, for that feel-good hormone surge you get following high intensity intervals that leave you feeling energised after your training session.

Of course, many clients also love interval training because it’s convenient. If you have a busy schedule and need to try and squeeze in workouts during a lunch break or first thing in the morning, interval training might be the most straightforward way to commit to your fitness goals.

The Science of Interval Training

Like any fitness training programme a qualified personal trainer puts together, there is a huge amount of sports science that goes into it – alongside an understanding of your general fitness level to ensure you maintain a challenging pace without overexerting yourself with hard intervals that are too much, too soon!

As a quick overview, working out for short periods at higher intensities means that:

    • Your aerobic and anaerobic systems are repeatedly challenged, which helps to metabolise the energy you store within your muscles.
    • While you are completing interval training exercises, your muscles utilise that glycogen to support the short bursts of activity.
    • Lactic acid is created as a by-product as you burn calories, resulting in an oxygen debt. Your body then has time to rest and recover during interspersed recovery intervals, giving your lungs time to replenish your oxygen stores and break down lactic acid.
    • The natural state achieved through this type of training session means your aerobic system gets to work, using oxygen to convert stored carbohydrates into energy – and you’re ready to go again.

While some clients are less interested in the sports medicine and technical aspects behind their training, it’s also important to appreciate that these short work intervals aren’t simply a way to increase your perceived exertion or burn more calories. Interval training actively contributes to boosting your speed and endurance and supporting long-term cardiovascular health.

Is Interval Training Good for Any Fitness Level?

Provided you work with an experienced trainer who can adapt your interval training workouts to your fitness, ensure you are training safely, and understand how to use your chosen equipment correctly, almost anybody can participate in interval training.

While maximum intensity might look different for each of us, there are profound benefits in both younger people and older adults who use treadmill running intervals or similar to improve their muscle mass, overall heart health and stamina.

If you’d like more information about how high-intensity intervals work, the best way to build this type of training into your exercise programme or to have a chat about customising interval training workouts for you, please get in touch with me at any time.