We don’t know if the ancient Spartans carefully prepared their lunch containers the day before marching off into battle, but we do know they sometimes went hungry. What’s this got to do with you? Well, if Hollywood is to be believed, Spartans – any many of our other ancestors, who had no choice but to move their bodies everyday, and occasionally go hungry – had naturally strong physiques and more energy than the garden variety office drone of 2022.
Though that’s quite a romantic way of looking at things (let’s be honest, our life expectancy is a lot longer now), there’s probably something to it.
On that note: if you want to score a little old school pizzaz for yourself, you might find the below chat between health hacker Dave Asprey and MD Amy Shah of interest, which was filmed during 2021, and recently posted by Asprey to Instagram (as part of a “best of” series).
Entitled “the #1 hack to increase your energy,” the video shows Asprey talking to Dr Shah, who has made it her mission to combine the best of old and new health knowledge and medicine.
In the video, Dr Shah recommends exercising in the morning sun while in a fasted state. She says: “two to three hours before bed – around sundown, maybe a little bit after sundown – stop eating, try to push through if you can or you have a tea or a coffee (or something without many calories), allow up to 40 calories as long as it’s not sugar and then you sleep.”
“Then you wake up [after having had] a good 8 hours and then you do a good fasted workout in the sunlight and that alone will fix so much of your energy, gut health, immune and hormone issues.”
Sounds pretty good. But does it add up? According to Healthline, it’s possible, but not a fully scientifically proven art.
First off, Healthline warns that working out in a fasted state can be risky because your state of low blood sugar could lead to lightheadedness, dizziness, shaking or even passing out, if you are not used to it, or if your constitution simply doesn’t agree with it (particularly if you are doing an intense workout).
However, Healthline says that “if you’re generally healthy,” it’s “probably fine” to do short or medium-length steady state fasted cardio sessions while fasting.
Healthline explains: “The idea behind fasted cardio is that if you fast overnight and work out first thing, your body is depleted of glucose — its main source of energy — and will instead use stored fat for fuel,” adding that there is mixed research on this benefit, with some studies strongly supporting the hy pothesis, and others finding that eating something before your workout can lead to enhanced performance.
Losing weight is just one thing though (you might not want to lose weight, for one thing). What about boosting your energy, as claimed by Dr Shah? Healthline says fasted cardio has other benefits such as saving you time (both in terms of preparing a meal and digesting it).
Healthline also states: “If you prefer working out on an empty stomach, fasted cardio could be an effective option, especially if you have a sensitive stomach or feel more energetic without a meal before a workout.”
Fasted cardio also has a number of other implications which you might want to take into account before doing it regularly. Some studies have suggested it could hinder muscle building and workout performance. It’s also not recommended if you are a person who typically has low blood sugar, or if you are pregnant.
Eating the right foods when you do eat is crucial, too, as Dr Shah has pointed out on other occasions.
This holds true for hedonistic foods as well. That’s why detoxing off of processed snacks and doing overnight fasting is essential to getting your pleasure centers in check.— Dr. Amy Shah (@Amyshahmd) January 4, 2022
Thank you @DocAmen pic.twitter.com/CLCdkBdraw
Looking elsewhere on the web, a 2020 study in the Open Access Journal Of Sports Medicine concluded: “The available data suggest that exercise in a fasting state decreases body weight, free fat mass and fat mass, although more controlled studies are needed for definitive recommendations to be made.”
“A moderate intensity exercise during fasting is recommended for the prevention of hypoglycemia. Training in the evening while fasting may be more effective in enhancing aerobic performance, compared to training in the morning. Athletes may wish to train in the fasting state in the pre-season as fasting increases the activity of fat-burning enzymes,” (Open Access Journal Of Sports Medicine).
“However, fasting can elicit negative effects on performance in some events, and hence modifications to the training schedules (eg fasting during the pre-season) may minimize such effects.”
As for working out in the sunlight, though you don’t want to get burnt, there is quite the body of literature showing that exposing yourself to non-harmful levels of natural light in the morning, soon after waking, can do wonders for your circadian rhythm.
There you have it. An exercise hack to ponder – and some interesting advice to sleep on.