Changed High-Intensity Interval Training (HIIT) to a less demanding cardio exercise; observed these adjustments affected my overall fitness.

In the realm of fitness, the ongoing debate between high-intensity and medium-intensity exercise has long been a topic of discussion. According to fitness expert Ruddock, both intensities offer unique and complementary benefits that can enhance overall health, fitness, and performance when incorporated into a fitness routine.

High-intensity exercise, such as HIIT workouts, aims to spend a considerable amount of time above 90% of maximum heart rate. This type of exercise is known for its ability to significantly enhance cardiovascular capacity, muscle power, and stamina, leading to improved athletic performance and endurance. High-intensity workouts also boost metabolism, causing increased calorie burning even after exercising, and strengthen the core and overall fitness through compound movements.

On the other hand, medium-intensity exercise, around 70 to 80% of maximum heart rate, has specific benefits compared to high-intensity training. Moderate-intensity continuous training (MICT) effectively improves VO2 max (peak oxygen uptake) and cardiopulmonary function, which is crucial for long-term cardiovascular health. Moreover, medium-intensity exercise yields similar benefits in body composition and physical function such as muscle endurance and mobility compared to high-intensity exercise.

The benefits of each intensity are not mutually exclusive; rather, they complement each other. By combining both, one can leverage high-intensity exercise for metabolic boost, fat loss, and muscle power, while medium-intensity exercise supports endurance, recovery, and sustainable cardiovascular improvements.

This approach offers a range of synergistic benefits—boosting metabolism and fat loss, improving endurance and heart health, strengthening muscles and core, and making fitness routines more adaptable and enjoyable over the long term.

A recent case study sheds light on the benefits of medium-intensity exercise. An individual who used to engage in high-intensity cardio workouts as part of a CrossFit-style training regime, doing at least three 10-20 minute HIIT workouts per week, became bored with this style of training and began focusing on strength training and playing tennis for an hour twice a week. Running and cycling feel easier for the individual after switching to medium-intensity cardio, and they noticed improvements in endurance after switching to tennis. However, the individual did not get the same level of endorphins after medium-intensity exercise as after a demanding HIIT class.

In light of these findings, the individual plans to add some short bursts of high-intensity exercise back into their routine, increasing the frequency over time. This balanced approach to exercise offers a sustainable and enjoyable way to maintain fitness levels while reaping the benefits of both high- and medium-intensity exercise.

In conclusion, incorporating both medium- and high-intensity exercise delivers synergistic benefits, making fitness routines more adaptable and enjoyable over the long term. By leveraging the unique benefits of each intensity, one can optimise improvements in aerobic capacity, anaerobic power, body composition, and overall physical function more effectively than either intensity alone.

References: [1] Tabata, I., Nishimura, K., Kouzaki, M., Hirai, Y., & Ogita, F. (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Medicine and Science in Sports and Exercise, 28(10), 1327-1330. [2] Gibala, M. J., & Little, J. P. (2012). The effects of 8 weeks of sprint interval training and moderate-intensity continuous training on aerobic fitness and skeletal muscle morphology. Journal of Applied Physiology, 112(4), 1041-1048. [3] Laursen, P. B., & Jenkins, D. G. (2002). The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes. Sports Medicine, 32(11), 827-841. [4] Helgerud, J., Hoydal, O. B., Berg, P. J., Gaustad, S., & Hoff, J. (2007). High-intensity interval training improves maximal oxygen uptake in middle-aged men. Medicine and Science in Sports and Exercise, 39(2), 295-301.

The individual's focus on strength training and tennis, a medium-intensity exercise, improved their endurance after switching from high-intensity cardio workouts.
Despite the improvements, the person did not experience the same level of endorphins after medium-intensity exercise as after a demanding HIIT class.
In response, the individual plans to add some short bursts of high-intensity exercise back into their routine, hoping to maintain fitness levels and reap the benefits of both high- and medium-intensity exercise.
This balanced approach to exercise, combining both medium- and high-intensity workouts, can offer a sustainable and enjoyable way to optimize improvements in aerobic capacity, anaerobic power, body composition, and overall physical function.

Changed High-Intensity Interval Training (HIIT) to a less demanding cardio exercise; observed these adjustments affected my overall fitness.