Fasting Before Exercise – Helpful?

Does Fasting Before Exercising Help Burn More Fat?

When I first started to work out well over a decade ago I bought all of the pre workout supplements and shakes I could find to increase my return on investment.  After a lot of money and some results I came to my senses.  When I picked up bodyweight training I started to focus on simplifying all things health and fitness.  If I wanted to be fit and health for as long as possible I needed a simple and sustainable approach to make that happen.  About a year  ago I switched to a fasted state prior to exercising.  What did I find out?  Keep on reading to see if being in a fasted state prior to working out helps burn fat and get you results quicker than not fasting…

My Experience of Fasting Before Training

Over the past  year I have seen great results from being in a fasted state prior to training.  If you eat before you workout, yes it is more fuel to burn, but you are mainly burning that fuel.  If you want to get lean and toned fasting before a workout will primarily focus on burning fat over burning the food fuel if you ate prior to working out.  Fasting before working out also has other great benefits.  Don’t just take my word for it, see the research article below:

A recent study sought to evaluate the effects of aerobic training in a fasted versus a fed state.

Specifically, 19 men were placed in one of two groups — one that practiced aerobic training after fasting for Ramadan (which requires fasting from dawn to sunset for one month), and one that did the training after eating.

During each session, subjects underwent anthropometric measurement, completed a dietary questionnaire, and provided fasting blood and urine samples.

The fasting group experienced reductions in both body weight and body fat, the latter of which remained unchanged in the fed group.

The researchers concluded:

” … aerobic training in a fasted state lowers body weight and body fat percentage. In contrast, fed aerobic training decreases only body weight. In addition, Ramadan fasting induced change in some metabolic parameters in FAST, but these changes were absent in FED.”

When you exercise while fasting, it essentially forces your body to shed fat, as your body’s fat burning processes are controlled by your sympathetic nervous system (SNS), and your SNS is activated by exercise and lack of food. The combination of fasting and exercising maximizes the impact of cellular factors and catalysts (cyclic AMP and AMP Kinases), which force the breakdown of fat and glycogen for energy.

 Fasting May Take Your Training Program to the Next Level

Simply put, exercise and fasting yield acute oxidative stress, which actually benefits your muscle. According to fitness expert Ori Hofmekler, acute oxidative stress is:

” … essential for keeping your muscle machinery tuned. Technically, acute oxidative stress makes your muscle increasingly resilient to oxidative stress; it stimulates glutathione and SOD [superoxide dismutase, the first antioxidant mobilized by your cells for defense] production in your mitochondria along with increased muscular capacity to utilize energy, generate force and resist fatigue.

Hence, exercise and fasting help counteract all the main determinants of muscle aging. But there is something else about exercise and fasting. When combined, they trigger a mechanism that recycles and rejuvenates your brain and muscle tissues.”

[Read the full article here What Will Cause You to Lose More Fat -- Exercising Fasted or Non-Fasted?]

In a previous post I wrote I touched on that I have a love hate relationships with intermittent fasting.  I enjoy eating quality foods.  But over the past year or so I have also seen great positive impacts on fasting before working out and doing intermittent fasting during the week.  I do need to say that before you try and fast prior to a workout or even during a week you need to have a chat with your doctor.  The last thing anyone wants to happen is have you try fasting before working out and end with low blood sugar and passing out.  You need to be healthy enough to fast.

Fasting is a solid option prior to working out to really target fat loss.  However I would say that after your workout you need to refuel your body to help restore your glycogen stores.  Ideally you would have a drink that has a 4:1 ratio within 45 minutes of working out.  See my post on having chocolate milk for a recovery drink

Closing Thoughts On Fasting Before Exercising

It depends on what your goals are.  For me I want to be lean and well toned and as fit as possible.  That is why I advocate bodyweight training.  Plus it is sustainable as you age and reduces dependencies on the gym and other equipment.  Fasting before working out is another tool that I use to keep my body well toned year round.  What are your thoughts on fasting before working out?