High-intensity Interval Training (HIIT) is a training technique in which short periods of intense exercise are alternated with brief recovery periods. This tends to maximise effort in a short time, it pushes one’s heart rate to a near maximum level, and then allows a brief recovery period before repeating the cycle.
Intervals of moderate to subdued activity or recovery time are common components of HIIT routines. People of different age ranges, fitness levels, and interests benefit from HIIT because it offers a variety of methods. Some common examples are alternating between cycling at maximum effort and light paddling, mountain climbing, squat jumps, or burpees; all these are a part of interval training.
People’s lifestyle has been drastically changing due to advancements, a shift in various aspects of life, including work, leisure, and eating habits. And hence, it becomes increasingly hard to burn calories since the key components of a weight loss journey are regular exercise and a balanced diet. HIIT becomes a model choice for people who lead a busy life but still need to maintain a healthy weight for their heart..
HIIT has various health benefits that are convincing to health-conscious people and fitness fanatics, and has demonstrated several benefits for the cardiovascular system.Here are the following benefits:
The Aerobic capacity (VO2 max) is the ability of your heart and lungs to deliver oxygen to working muscles, and research has shown that HIIT aids in moderating the intensity of cardio for improving VO2 max.
HIIT, with its short but intense bursts of activity, enhances insulin sensitivity and is beneficial for individuals with or at risk of Type 2 Diabetes by helping regulate blood sugar and lipid levels. Additionally, it contributes to lowering triglyceride levels and increasing HDL (good) cholesterol, further supporting metabolic and cardiovascular health.
Despite exemplary potential health benefits of HIITS, there is an aspect to it that could be a potential risk too, such as:
1. Extreme physical activities may trigger an arrhythmia, also known as cardiac arrhythmia. This happens when the rhythm of the heartbeat is too fast, too slow, or has an irregular pattern. For people with already existing cardiac conditions or a family history of such cardiovascular irregularities, HIIT can trigger irregularities, since it is intensive exercise in a short period of time.
2. Rapid intensity changes can provoke chest pain, spike in heart rate and blood pressure, so due to this, jumping into HIIT without a proper long-term adherence can cause issues. Those with asthma or other lung conditions may also experience shortness of breath, and if this continues for a long period of time, it can cause narrowing airway, also known as Bronchospasm, wheezing, coughing, and severe asthma flare-ups.
3. The risk of overtraining and injury pertains to HIIT. It can cause an increase in the cortisol levels, making it surge during the session; if a person is already tired or stressed from their daily routine, doing a HIIT workout can add more pressure, which in turn overloads your body’s stress response. This can cause the person to be burnt out rather than feeling energised. This leads to chronic fatigue, reduced motivation.
4. Excessive High-Intensity Training without an adequate foundation can result in performance regressions and a heightened risk of injury. In the absence of proper preparation and sufficient recovery between HIIT sessions, compromised form and reduced motor control may place undue strain on muscles, tendons, and joints, potentially leading to injuries that may not fully resolve.
The question arises of whether HIIT is the right choice for everyone. The technique does place a lot of stress on your heart, lungs, and joints; hence, individuals with a high degree of physical fitness are the ideal candidates. On the other hand, people who are looking for less complicated workout plans are ideal, but it is also important to choose the fitness level of HIIT and keep in mind the health status of the individual. It is advisable to refer to a doctor before starting HIIT if you have pre-existing medical conditions.
Methods for the safe implementation of HIIT
Safe implementation of HIIT is to gradually start slowly and allow yourself time to incorporate this workout session into your routine. Avoid impromptu starts, rather have a light warm-up session of 5-10 minutes and end with the cool down.
It is important to listen to your body throughout the intervals without going overboard. A heart rate monitor can be used for an efficient and risk-free HIIT session. It is also significant to prioritise recovery between the HIIT sessions since it is important for your heart to adapt.
(The writer Dr Vivekan Manoharan is a consultant in the Department of Cardiology at MGM Healthcare, Chennai)