Concepts such as high-intensity interval training (HIIT) and metabolic training are more and more frequently cropping up in articles and discussions about fitness. But what do these concepts actually entail and why are they being hailed as the future of fitness and our roadmap to longevity?
When we reach our thirties, our growth hormones start to drop dramatically. This is a natural part of growing older. This decline in growth hormone is further exasperated by the sedentary lifestyles that we tend to live. In order to continue to feel younger, healthier and more energised for longer, we need to find a way in which to maintain or increase the levels pf human growth hormone (HGH) produced by our bodies. How can we achieve this?
This is where metabolic training or HIIT comes in! If we regularly engage in short bursts of exercise, typically a training pass should last no longer than 20 minutes, we will stimulate the production of HGH providing benefits such as:
- Normalisation of insulin and glucose levels
- Lowering of body fat
- Improved muscle tone
- Increased energy levels
- Improved mental alertness
Essentially, we have three types of muscle fibre and it is the fastest type that we need to target (the twitch muscle). These are engaged during anaerobic (without oxygen) short bursts of exercise, so the key is to do very short bursts of vigorous exercise taking you to your anaerobic threshold. Signs of having reached this level include:
- Being out of breath (as you lack oxygen)
- You start to sweat
- Your body temperature rises
- Lactic acid is produced and you feel the “burn” in your muscles
Such a burst must be followed by a period of recovery and the best effects are achieved if the same exercise is completed in a series of repetitions followed by a period of recovery each time. These super-fast twitch muscle fibres move at ten times the speed of the slow muscle fibres (used for endurance training) and this is why the effects are so profound just from a routine consisting of short bursts of exercise lasting no more than 20 minutes in total, including warm up and recovery.
Interestingly, if we engage in lots of long-distance/ endurance training, we may negate the positive effect of any HIIT training that we do as this type of training may work to diminish the fastest (anaerobic) types of muscle fibres that we have.
Also, beware of drinking soft drinks or sports drinks after your workout! Consuming glucose or fructose, in particular if consumed within the first few hours of your workout, will stun the production of the human growth hormone.