Interval training is a scientifically supported method of exercise that aims to maximise results in less time. This approach is widely recognised in the fitness community. This blog will look at the science of interval training and evaluate its effectiveness as a workout strategy. So, let’s get to it, but firstly…what is Interval Training?
Interval training, also commonly known as ‘high-intensity interval training’ (HIIT), involves alternating between short bursts of intense activity and periods of rest or low-intensity exercise. This method pushes your body to near maximum effort during high-intensity phases, followed by brief recovery periods. It challenges the body to work at high intensity heart rate (HR) zones forcing your HR values to sky-rocket.
The Physiological Advantages of Interval Training
Aerobic and Anaerobic Benefits
Interval training is known for its capability to improve both aerobic and anaerobic fitness simultaneously. Research suggests that HIIT training can induce several physiological adaptations that enhance exercise capacity, such as improvements in maximal oxygen uptake (VO2max), aerobic endurance, and anaerobic capacity.
Time-Efficient Results
HIIT is highly time efficient. As studies show it can achieve the same or better results compared to moderate-intensity continuous training (MICT) in less time. This makes HIIT ideal for those with busy schedules seeking effective workouts. For example, those who have short lunch breaks, or short windows of opportunity when doing school runs, or between appointments.
Metabolic Enhancement
Research indicates that interval training can elevate resting metabolic rate and enhance substrate metabolism (the energy we use during exercise). Consequently, post-exercise, the body continues to burn calories at a heightened rate, aiding in better body composition and weight management.
Running Performance
A 2025 study found that sprint interval training significantly improved time to exhaustion (TTE) and running performance in well-trained male distance runners. The interval training group performed better in the 3000m event than those who only did continuous training.
Muscle Power and Endurance
Interval training not only enhances cardiovascular fitness but also improves muscular power and endurance. The high-intensity exercises promote neuromuscular adaptations, which, over time, could result in increased muscle fibre recruitment and faster muscle contraction rates. Consequently, also resulting in increased performance rates such as enhanced sprint mechanics, improved acceleration, and more efficient energy utilization during physical activities.
Health Benefits Beyond Fitness
Cognitive Function
Research indicates that high-intensity interval training (HIIT) offers superior cognitive benefits over less vigorous routines, with potential long-lasting effects. HIIT may help maintain cognitive function as we age.
Cardiovascular Health
Interval training can reduce the risk of cardiovascular diseases. The intense bursts of movement during HIIT sessions challenge the heart and blood vessels, leading to improved cardiovascular health.
Metabolic Health
Studies have shown that HIIT can improve insulin sensitivity and glucose regulation. This suggests that interval training may be useful in preventing and managing metabolic disorders such as type 2 diabetes.
Body composition
Research suggests that high intensity interval training can have positive effects for individuals who are looking to make changes to their body composition e.g. increase lean tissue and/or reduce excess fat mass.
How to Incorporate Interval Training
To safely and progressively incorporate interval training into your workout routine, consider the following tips:
- Always include a proper warm-up and cool-down before engaging in interval training
- Try a variety of interval training methods e.g. HIIT, sprint interval training and/or repeated sprint training.
- Beginners should start with shorter intervals sessions and gradually increase the intensity and duration over time.
- Pay attention to your body’s signals/needs/ability levels and allow for adequate recovery between sessions.
- If you’re unsure of where to start, consult a qualified fitness professional or healthcare practitioner before starting, particularly if you have any pre-existing health conditions.
The Future of Fitness
In our current world, everyone’s lives are busy, and most individuals have insufficient time to exercise. Interval training is more than a trend; it’s efficient, beneficial for health, performance and easily customised to suit different ability levels, lifestyles and training styles. It is suitable for recreational exercisers to elite level athletes. It is a scientifically backed training method that can help individuals from all different exercise/fitness backgrounds, reach their fitness and health goals quickly.
While interval training and continuous exercise can both elicit positive outcomes on an individual’s health and performance, interval training has been shown to demonstrate higher levels of enjoyment and greater physiological adaptation. Where possible, interval training should be part of a balanced fitness program that includes various exercises, proper nutrition, and rest. It is also important to mention that most research conducted around interval training has been done on male subjects, warranting further research to be done in this area using female subjects.
Are you ready to give it ago?
References
Buchheit, M. & Laursen, P. B. (2013). High-Intensity Interval Training, Solutions to the Programming Puzzle. Qatar: Sports Med.
Jin, K., Cai, M., Zhang, Y., Wu, B., & Yang, Y. (2025). Effects of 6-week sprint interval training compared to traditional training on the running performance of distance runners: a randomized controlled trail. England, United Kingdom: Frontiers.
Stoggl, T. L., Strepp, T., Weisinger, H. P. & Haller, N. (2024). A training goal-oriented categorization model of high-intensity interval training. Qatar: Frontiers.
Vollaard, N. B. & Metcalfe, R. S. (2017). Research into the Health Benefits of Sprint Interval Training Should Focus on Protocols with Fewer and Shorter Sprints. England, United Kingdom: Sports Med.
