By: Tomas Agrimbau, Co-Founder, and Sofia Palumbo, Product Owner, at Amalgama.

As fitness enthusiasts search for effective ways to maximize their workouts and get fitter, one method stands out in the crowded world of fitness:  Zone-Based Interval Training (ZBIT). This innovative approach combines the principles of heart rate training with interval workouts, making it a powerful tool for improving cardiovascular fitness, boosting metabolism, and enhancing overall athletic performance. 

What is Zone-Based Interval Training?

ZBIT involves alternating periods of high-intensity effort with lower-intensity recovery, all while keeping your heart rate within specific zones. These zones are typically defined as percentages of your maximum heart rate, allowing you to target different physiological responses during your workout. For example, Zone 1 & 2 workouts are excellent ways of improving our ability to take in and utilize oxygen while efficiently transporting it to working muscles. They are also great active recovery zones for intermediate and advanced athletes. 

• Zone 1: Very light (50-60% of max heart rate)
• Zone 2: Light (60-70% of max heart rate)
• Zone 3: Moderate (70-80% of max heart rate)
• Zone 4: Hard (80-90% of max heart rate)
• Zone 5: Maximum effort (90-100% of max heart rate)

Why Zone-Based Interval Training Works

ZBIT  science is effective because it takes advantage of the body’s energy systems. During high-intensity intervals, your body primarily relies on anaerobic energy pathways, which improve your speed and power. During recovery intervals, you shift back to aerobic metabolism, allowing your body to recover while still burning calories.

What are some of the benefits of ZBIT?

• Increased Caloric Burn: By incorporating high-intensity efforts, you boost your metabolic rate, allowing you to burn more calories during and after the workout.
• Improved Cardiovascular Fitness: Training in higher heart rate zones enhances your heart’s efficiency and increases your aerobic capacity.
• Time Efficiency: This type of training  allows for a complete workout in a shorter amount of time, making it ideal for those with busy schedules.
• Adaptability: This training method can be applied to various forms of exercise, including running, cycling, swimming, and group fitness classes.

How to calculate your MHR and start implementing ZBIT in your workouts 

To incorporate ZBIT into your routine, firstly you need to determine Your Maximum Heart Rate (MHR). A common formula is 220 minus your age, which will then help you determine the rate for each Heart Rate Training Zone. Nowadays, this is not needed, as many wearables can calculate this measurement more accurately, a good example is Morpheus M7. 

Morpheus’ device allows users to track their Heart Rate Variability, and in addition, it uses it to calculate a personal recovery score and daily heart rate zones. The recovery score gauges  the balance between the amount of energy a person has been spending putting their body under stress vs. the amount spent on recovery over the last few days. This number is used as an indicator of the energy available to train on that specific day and helps determine the type of workout and interval zone that is best to stick to for long-term gains in health, fitness, and performance.

Once you have determined the range of your target zones, you can design your workout around the amount of time you aim to spend at specific target zones depending on your training goals. An example of a ZBIT session might include:

• Warm-Up: 5-10 minutes in Zone 1
• Intervals: Alternate between high-intensity (Zone 4-5) for 30 seconds to 2 minutes and recovery (Zone 2) for 1-3 minutes.
• Cool Down: 5-10 minutes in Zone 1

Utilizing Wearable Devices such as heart rate monitors and fitness trackers can help you keep track of your performance and accurately gauge your intensity levels during workouts. Devices like the Garmin Forerunner and Polar H10 chest strap provide real-time feedback on your heart rate, ensuring you stay in your desired training zones.

The Rise of Zone Two Training

When talking about ZBIT, Zone Two training has recently started to gain more attention, becoming a bit of an obsession for many fitness enthusiasts aiming to meet their aerobic goals. 

The reason behind this favoritism is that keeping your heart rate on Zone Two while working out is particularly effective for building aerobic capacity and improving endurance, allowing the body to utilize fat as a primary fuel source. Unlike high-intensity workouts that may be intimidating for beginners, Zone Two offers a comfortable pace where individuals can maintain a conversation while exercising. This approach not only supports long-term fitness goals but also minimizes the risk of injury, making it an appealing option for those looking to maintain a consistent workout routine. 

Popular Workouts Utilizing Interval Training

If you are a fitness enthusiast, there is no doubt you have trained or at least heard of some of the most well-known interval training routines. Before delving into some examples it is important to clarify that intensity interval training does not always consider heart rate zones. Interval training uses individualized heart rate zones and works with a range of different intensities, allowing for more personalisation and progression tracking.

1. HIIT (High-Intensity Interval Training): Many HIIT workouts are built on the principles of zone training, with intense bursts of activity followed by rest.
2. Fartlek Training: Fartlek training was first developed in the 1930s, in Sweden, and translates roughly into English as ‘speed play’. This method combines continuous training with intervals, allowing for varied pacing during runs and introducing unpredictability. This can be particularly beneficial for enhancing mental agility and improving focus. 
3. Tabata Training: A specific form of HIIT that follows a 20-seconds on, pushing it to the limit, and 10-seconds off structure, often targeting the anaerobic system. This cycle is repeated eight times, completing a 4-minute set. 

To conclude, by understanding your heart rate zones and incorporating high-intensity intervals into your routine, you can unlock numerous benefits, from enhanced endurance to increased caloric burn. Whether you’re a seasoned athlete or just starting your fitness journey, ZBIT offers a structured yet flexible approach that can elevate your training to new heights.

Tomas Agrimbau, co-founder of Amalgama. Entrepreneur, passionate about innovation and technology. Like many founders, he’s taken on various roles at Amalgama, primarily as CTO and Head of People. Father of two, runner, and former sailing competitor.

Sofia Palumbo, Product Owner at Amalgama. Over six years of professional experience in strategic Project Management and Innovation roles in Australia. Part-time writer, runner, and an eager tennis and paddle competitor.