Chris Shugart
The Worst Time to Lift?
Fasted resistance training has a couple of pros but a whole lot of cons. Here's what you need to know.
I've been lifting for 30 years. I've been a morning, noon, afternoon, and nighttime lifter. For me, morning lifting is best. The biggest challenge is nutrition. Fasted resistance training never seemed smart, but I didn't want to train on a full stomach, either.
I've seen coaches praise fasted weight training, and other coaches poo-poo it. Who's right? Let's dig into it.
Fasted AM Lifting: Questions and Answers
1. Do you lose fat faster?
It's a common claim: Fasted workouts increase fat oxidation and enhance fat utilization. But do they?
First, the elephant in the room: Fat loss isn't the main goal of weight training. Yes, the long-term metabolic boost from having more muscle leads to fat loss and having an easier time staying lean, but we don't lift to burn calories; we lift to build muscle and strength. Fat loss is adjacent and better addressed through diet.
That aside, most of the studies cited by pro-fasted-lifting advocates are on aerobic/cardio workouts, and those studies are mixed. Some studies show that you mobilize more stored fat when doing fasted exercise; however, the total number of calories burned remains similar between fasted and fed states.
A study in the Journal of the International Society of Sports Nutrition examined body composition changes over four weeks of aerobic exercise performed in either fasted or fed states among women on a hypocaloric diet. There were no significant differences in weight loss or fat mass reduction.
Another cardio study (Paoli et al.) found that more fat was used for fuel in the fasted state, but the opposite happened after the workout: fat utilization was significantly higher in the fed group for up to 24 hours. In other words, the fasted trainers burned a little more fat during the workout but burned less the rest of the day. Fasted cardio led to lower resting energy expenditure (fewer calories burned) and less total fat utilization over 24 hours.
Many fasting lifters will balk, claiming they've noticed faster fat loss. But, most likely, training fasted simply had a downstream effect where they consumed fewer total daily calories. That caused the fat loss, not the fasted workouts.
2. Are your lifting workouts more focused when fasted?
It's possible. Training on an empty stomach improves cognitive sharpness for some because digestion isn't competing for energy. However, this may come down to what you're eating (and how much) before the workout.
Training fasted elevates your already-high morning cortisol levels. This can feel good in the short term. Cortisol enhances cognitive function, reaction time, and focus as part of the fight-or-flight response. Cortisol also mobilizes glucose and fatty acids for energy, temporarily boosting stamina.
So, is that "stress hormone high" worth the price of cortisol's other effects on the body, like muscle protein breakdown? Lifting weights with the muscle-eating hormone coursing through your body doesn't seem like a great idea, even if it makes you feel perky.
3. But aren't GH and testosterone highest in the morning?
Yes, growth hormone (GH) and testosterone tend to be higher in the morning for men due to their natural circadian rhythm. GH spikes highest during deep sleep, but it's still elevated in the morning. Testosterone follows a diurnal rhythm, peaking in the morning (around 6-8 AM) and gradually declining throughout the day.
This might be a good reason to train in the morning, but it doesn't matter much if you're fed or fasted. Resistance training can further stimulate GH secretion in the morning, but this extra boost just doesn't seem to make a difference in actual muscle or strength gains – it's a drop of water in the ocean.
At best, elevated morning GH and T might help reduce some of the drawbacks of fasted lifting compared to, say, afternoon fasted lifting, but the cons of fasted resistance training outweigh any possible pros.
The Big Drawbacks of Fasted Lifting
- Crappy Workouts – Glycogen stores are lower in the morning, leading to decreased strength and power output. Without readily available glycogen, high-intensity lifting sessions may feel harder, limiting total workload (volume and intensity). Weakness triggered by low blood sugar (hypoglycemia) can also be an issue.
- Increased Muscle Breakdown (Catabolism) – Again, this is due to cortisol.
- Blunted Muscle Protein Synthesis – Without amino acids circulating in the blood, muscle repair and growth are compromised.
What to Consume Before AM Lifting
Okay, so fasted weight training sucks. So, what do we do about the problem of lifting weights at 7 AM with a belly full of food? Easy: Drink breakfast.
First, you want the right carbohydrate for energy and to top off glycogen stores without causing bloating or rapid blood sugar spikes. Highly branched cyclic dextrin (HBCD) is the best choice. HBCD has a low osmolarity – it digests and absorbs quickly without causing bloating or gut distress. This allows it to rapidly replenish glycogen compared to slower-digesting carbs. Unlike dextrose or maltodextrin, HBCD provides a steady release of glucose, preventing energy crashes.
Second, you want an amino acid for muscle protection and increased protein synthesis. Leucine is the master amino acid for lifters.
Third, you need a blend of electrolytes. Overnight respiration and perspiration deplete electrolytes, so you need more than a glass of water upon waking if you're headed to the gym.
Although our Surge Performance Fuel (Buy at Amazon) drink wasn't specifically designed for early-morning lifters, it checks all the boxes. Surge contains HBCD, leucine, and electrolytes, along with other performance boosters like beta-alanine. The only thing a morning lifter might want to add is a little creatine, but that's optional and may work best taken after training.
Begin drinking Surge at least 15 minutes before training and continue sipping it during.
