The evidence for intermittent fasting being useful, or at the very least effective, for physique competitors is compelling.
But what if you aren’t a physique competitor?
After all, physique is different than performance.
And the reality is that most everyone high on fasting is a fitness professional, most of which are only concerned about looking good.
But what about those of us that are…a little more?
What about someone like myself, that lifts, tricks, and plays recreational sports? What about the days when I lift early and play late?
In other words, what if your life isn’t optimized solely for weight-training workouts? And what about life beyond the barbell?
Fasting for weight-training is all well and good, but we’re talking about performance here. Can fasters still perform at a high level?
A QUICK NOTE ON THE SCHEMES
To do my best at generalizing, I focused on the extremes. For instance, seeing no performance impairment after a 3.5 day fast makes it easier to predict shorter duration fast effects.
RAMADAN TO THE RESCUE
When it comes to performance and intermittent fasting, we lucked out. There’s a host of athlete specific fasting research thanks to the religious observance of Ramadan.
During Ramadan, participants fast from both food and drink from sun-up to sun-down. So it’s tremendously hellish compared to most of our comfy fasting experiments that have us sipping on coffee and chugging water.
Keep that mind: these athletes are going without food and drink. It’s safe to say that they would undoubtedly perform better with some kind of hydration.
YOUR INITIAL PREDICTIONS ARE WRONG
No food or drink for hours upon hours? Performance has to drop. Right?
I would think so too.
But this just isn’t the case.
Many studies (see end of post) and stories show athletes of all shapes and sizes doing just fine without both food and drink. But there are also some downsides.
Here’s a quick rundown:
- Performance, for the most part, is maintained.
- Performance never increased as a result of fasting.
- During Ramadan, few athletes eat enough to match caloric demands.
- But when body weight is lost, it’s mostly fat, not muscle mass.
- Huge feasts before bedtime can negatively affect sleep.
- Experienced Ramadan athletes handle the fast better and have performances to show for it.
- Anticipatory feelings towards a meal can disturb performance.
It’s safe to say that performance—for the most part—can be maintained on an empty stomach.
Overall, it seems athletes with stable mindsets do the best. So craving food and obsessing over hunger is foregone failure.
Anyone that ventures into intermittent fasting knows that it takes time to get used to new eating patterns. And yet these athletes are suddenly thrown into a situation without both food and drink for 12-or-so hours. So their maintenance of performance markers is impressive. The big take home here is that hunger is apparently what you make of it.
HANG UPS WITH FASTING FOR PERFORMANCE
More so than specific nutritional demands, the main consideration for an athlete and fasting is living at the extremes.
What I mean by this is that you’re either hungry, or you’re full. A hungry athlete isn’t going to perform well unless they are mentally conditioned to accept hunger as an arbitrary feeling. Most people, however, associate hunger with depletion.
But the other side might even be worse—performing on a full stomach. Big meals increase parasympathetic nervous system activation. Think of the Thanksgiving sleepy effect. Not good.
WALKING THE LINE
The ironic part about intermittent fasting and performance is that if you’re considering it (or even experimenting with it), you likely have a better diet than most professional athletes. (Who usually eat garbage. To the left is Michael Phelps's “diet.”)
To decide whether or not fasting is for you, and to see how to arrange it around your activities, first ask yourself if you thrive or dive on hunger?
If you can manage hunger fine, the Ramadan studies show that most performance markers can be maintained.
Here are some suggestions:
- Have your biggest meal later in the day, after any strenuous activity. Don’t worry about eating late, it might even benefit you. But don’t overly jam calories down your throat before hitting the pillow, as it can funk up sleep.
- Don’t eat any big meals 6-8 hours before activity.
- Follow a general template of scheduled meal times, but don’t be overly anal about it. Late games might mean eating a larger meal at 10-11PM. That’s OK, even if your last meal should be at 8ish.
- If you’re doing anything strenuous for over an hour, think about getting something small in your stomach beforehand. Not so close to the activity, but not so far either. Just make sure it’s small enough to feel “neutral.” Don’t be starved. Don’t be stuffed.
- This is more of a personal anecdote, but a heavy dose of carbohydrates prior to activity never ends well. On almost every experimental trial, carbohydrates (outside of something small like fruit), resulted in a crash and burn. So if you lift early and play late, save the big carbohydrate meal for later (not post-workout).
- If you’re having trouble fitting in the calories, be sure to optimize your “off days” when nothing is planned. So maybe a few hectic days can't be as “structured” as you prefer, and you can't eat enough and adhere to fasting principles. Just take the hit. But fill up on the days that allow for more structure.
- If you want to carb cycle, be mindful of what kind of athlete you are and what your macro demands are.
The big takeaway here is that hunger isn't going to kill your performance. Every day, collegiate and professional athlete's train at 6AM. The vast majority don't eat anything before their training. Most of them are still half asleep, actually.
When your feeding period starts, eat or or two smaller meals. Don't get full. Don't be starved. (Unless you can mentally tame hunger because, really, performance won't take much of a hit.) Save your big meal for after any practice, games, or activity.
Do you have any experience with fasting and activity outside of weight-training? I'd love to hear your opinion, so post it in the comments. I'll see you there.
Findings: Before Ramadan, athlete’s had better night performances. During Ramadan, peak power dropped at night, but still matched morning performances. Perceived feeling of fatigue increased at night.
Findings: Opinions all over the place. Half of participants said Ramadan had no effect. Over half said they were tired during the day. Only 40% were able to maintain caloric intake.
Thoughts: Maybe ones that reported fatigue couldn’t maintain intake?
Findings: Most athlete’s couldn’t consume enough calories, bodyweight dropped. But there minimal to no drop in performance. Average deficit around 500 calories.
Findings: Performances requiring sustained rapid responses decreased in evening. Performances not dependant on speed stayed the same.
Findings: “Separately, a single bout of endurance exercise places similar metabolic stress on the body as fasting since the exercising muscle must reduce its use of carbohydrate and utilize lipid more readily as exercise progresses. Not surprisingly therefore, adaptations in muscle to repeated bouts of endurance exercise (endurance training) are similar to those seen with repeated fasting/refeeding.”
Findings: “Overall patterns revealed that experiences associated with physical, emotional, behavioral, and spiritual dimensions dominated in the first phase of fasting, while the mental dimension surfaced increasingly in the latter phase of fasting.”
Findings: No difference in performance. But bodyweight dropped.
Findings: Fasting didn’t affect aerobic and alactic anaerobic performance. Anaerobic lactic suffered a bit.
Findings: Didn’t affect performance.
Findings: “Whereas subjective feelings of fatigue and other mood indicators are often cited as implying additional stress on the athlete throughout Ramadan, most studies show these measures may not be reflected in decreases in performance. The development and early implementation of sensible eating and sleeping strategies can greatly alleviate the disruptions to training and competitiveness, thus allowing the athlete to perform at a high level while undertaking the religious intermittent fast.”
Findings: Perhaps intermittent fasting can enhance recovery?
Findings: “At the end of Ramadan fasting, a decrease in MVC was observed (-3.2%; P < 0.00001; η, 0.80), associated with an increase in the time constant of oxygen kinetics (+51%; P < 0.00007; η, 0.72) and a decrease in performance (-5%; P < 0.0007; η, 0.51). No effect was observed on running efficiency or maximal aerobic power.”
Findings: Hormones mostly stayed the same through Ramadan, but there were some sleep disturbances and increased adrenaline overall.
Findings: Zero performance effects.
Findings: Experienced athletes are able to maintain performance.
Findings: Zero effects.
Findings: Caloric intake reduced. There was more fat used as a fuel substrate and lower body fat levels found after Ramadan.
Findings: Decreased performance. But what’s interesting is that players thought there would be.
Findings: Reduced body fat levels and able to maintain training load.