Intermittent Fasting For Fitness

Intermittent fasting is one of the hottest buzzwords in fitness right now. So what is it and what are its benefits? Put simply, intermittent fasting is a controlled pattern of eating in which you cycle between eating and not eating (i.e. fasting). It’s not necessarily a “diet” if you don’t alter your food intake (either in terms of what you eat or how much you eat); this is especially the case when fasting for medical or religious reasons. However, when fasting for fitness, proponents argue it results in numerous health benefits. In this article, we’ll explore a few of them.

 

Check before you fast!

Before going further, it’s essential to point out that fasting is not for everyone. While periods of food abstinence may have some health benefits for some people, it may also be unhealthy or dangerous for others.

• Those with diabetes or blood sugar issues may suffer dangerous spikes or crashes in blood sugar levels and fasting is not recommended for these individuals.
• Fasting is also not advised:
  • For adolescents;
  • If you’re pregnant, trying to conceive or breastfeeding;
  • If you have low blood pressure, kidney stones, or suffer from reflux;
  • If you are susceptible to eating disorders;
  • If you have other medical problems or are on medication.
• Medical advice is always strongly recommended and people with underlying health conditions may require medical supervision even if they receive medical approval to fast. Always consult your doctor to make sure!

 

Types of fasting

Intermittent fasting is a type of fasting where food is restricted (partially or completely) for a certain number of hours/days and a normal diet is maintained at other times. It can be broken down into sub-types including:

1. 16/8 fasting: fast for 16 hours, eat during an 8 hour window only (usually during the later part of the day). This is sometimes known as time-restricted fasting and is generally regarded as the most popular type of intermittent fasting as it’s the easiest to stick to.
2. 5:2 fasting: in this type of fast, a person will eat normally for 5 days of the week but restrict eating (or don’t eat) for 2 days. This is sometimes known as (a type of) periodic fasting.
3. Alternate-day fasting: fasting takes place on a one-day on, one-day off pattern. On fasting days, the individual may tightly restrict calories consumed or not eat at all.

In general, liquids are normally fine during a fast including water, tea and coffee. The caveat is any liquids must be completely plain – no milk, sugar or other calorie-laden additives!

 

The mechanics of fasting

When you eat regularly, your body will spend 4-6 hours processing that food. It will burn the energy it needs from that readily available food energy and store the rest as sugar in your muscles and liver (in the form of glycogen) and fat. However, when you fast, your body doesn’t have readily available food energy to use anymore so it will deplete its limited stores of glycogen first and then begin burning fat.

 

Benefits of fasting

1. Fasting helps your body control blood sugar levels by reducing insulin resistance. Improved insulin sensitivity means your body is more likely to immediately burn food energy or store it as glycogen rather than converting it to fat. Fasting essentially conditions your body to use food more efficiently and burn fat for energy more readily.
2. Fasting can improve blood pressure and cholesterol levels. This reduces the risk of heart disease, which counts for as many as a third of deaths every year globally. It can also lower the risk of diabetes, which is itself a risk factor for heart disease.
3. Fasting can help boost brain function – you may feel more energy and increased ability to concentrate – so called “mental clarity”.
4. Fasting can aid weight loss since you’re likely to decrease your calorie intake and boost your metabolism, ensuring lean body mass.
5. Fasting has been shown by research to reduce inflammation in the body, potentially helping to stave off chronic health conditions/ailments such as heart disease and arthritis.
6. Fasting can naturally and dramatically increase your body’s level of human growth hormone (HGH), a key hormone involved in metabolism, weight loss and muscle strength. Fasting also keeps blood sugar and insulin levels steady through the day, helping to ensure optimum levels of HGH. Higher levels of HGH make fat loss and muscle gain more likely.
7. Fasting can stimulate the body’s cell repair processes. This is because fasting puts your body under mild stress and triggers a process called autophagy in which your cells check and repair themselves. This can have an anti-aging effect and also reduce inflammation in the body.

 

 

Fasting timeline – what happens in your body during a fast

4-6 hours: your stomach empties.

6-12 hours: your digestive system slows, insulin levels drop; your body burns stored glucose/sugars (glycogen); once your body’s limited glycogen reserves are depleted, it begins to run on fat stores.

12-24 hours: your body runs on fat; your liver produces ketones from fatty acids to power your brain (potentially resulting in increased mental clarity); autophagy (cellular repair begins); inflammation decreases; HGH increases to support your metabolism.

24 hours+: blood sugar and insulin are low; urea nitrogren increases from protein breakdown; muscle loss may begin.

 

Adverse effects

Fasting may not be effective for everyone. Side-effects include constant hunger, irritability, nausea, headaches, dizziness, insomnia, and decreased mental acuity. Some studies have also suggested that fasting may be of more benefit to men than women: whereas men benefited from improved insulin sensitivity, the opposite was the case in women. Other studies have reported altered menstrual activity and fertility difficulties while fasting.

 

Working out while fasting

You can work out while fasting; in fact, it may help you burn fat stores as your body will have no other energy source available. While this is good in theory, in practice some individuals may find working out while fasting uncomfortable (e.g. they feel light-headed or dizzy) or feel they lack the energy to train as intensively as they’d like.

 

Practical Considerations

Many people who practice intermittent fasting are able to eat as much as they would normally – or even whatever they like. The difference is they only eat during a limited window during the day. Nevertheless, when fasting, it is advisable to take extra care to:

• Drink more water to stay hydrated;
• Keep your electrolyte levels up;
• If you train while fasted, make sure to eat after your workout.

 

Fasting is an eating strategy that can help you improve your fitness without having to “diet” per se. However, it is not suitable for everyone and some individuals may find the process unsuitable for their lifestyle or unsustainable for them physically. Given the touted health benefits, it’s worth trying out if no health risk factors rule you out, but it’s not the be all and end all if you can’t or don’t want to practice it. Like so many other buzzy wellness ideas, intermittent fasting is just one potential tool in your fitness arsenal. Whether you can or want to use it is up to you!