Our expert says:
Improved fitness is obviously a consequence of both. Without going into the biochemistry and physiology of it, the main difference is that HIIT challenges a different energy system, the result being that your body becomes more accustomed to dealing with the intensity. They are more effective for people looking for very specific gains in fitness. Rugby, hockey, or soccer players can't do without this, because to play sport requires that kind of physiological adaptation. THere's also a lot of cardiovascular adaptations, and of course, you're teaching muscle to contract a lot faster and more forcefully, and so your co-ordination and strength improve as well.
Long cardio workouts are better for improving your body's ability to sustain exercise, and this happens because you adapt by creating more "aerobic capacity" - your heart and lungs, and body's ability to transport energy around is improved. The gains you get from this are those that would create a good marathon runner.
There are risks, of course. You can't do HIIT too often, because you will get injured or burned out. Similarly, if you do very long sessions all the time, the risk of overuse injury rises. So there is a balance between them, and a third session which is a short and lower intensity workout - call it active recovery.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.