Resting for Strength

By: Noah Hayden, PBC

For a committed lifter, it is easy to make the mistake of excess. Cram in as much work as possible because more is better, right? (I think our modern work culture of perpetual growth predisposes people to overwork or feel guilty about being "lazy," but I digress.) Unfortunately, excessive training is a short path to stalled progress. A more-is-better attitude will often lead to plateaus, injuries, or backsliding.

Your body is not aware of your goals or timelines. It is in charge of managing and orchestrating a variety of physiological processes that it adapts to meet the demands of your environment as best it can, irrespective of any notions of success or your preferred level of impatience.

There are limits to how quickly your body can perform its functions. It needs rest between bouts of effort to perform at its best and to adapt to long-term habits—intentional or otherwise. If you want sustained progress over many years, you will need to give your body time to keep up with your training sessions.

This applies to programming and lifestyle choices in the long term—adjusting frequency, volume, intensity, nutrition, and recovery to match your body’s rate of adaptation. In the very short term, too little rest may prevent you from completing the sets and reps of a single workout, potentially interrupting steady progress and undermining the value of that workout.

Different Types of Metabolism

Your body seamlessly employs a handful of different metabolic strategies to allow you to move in the ways you are accustomed to. The easiest way to categorize these is into two groups: aerobic and anaerobic—those that require oxygen to function and those that do not, respectively. These categories are a bit misleading because your cells are always in the presence of oxygen. It is important to remember that all of these pathways are constantly functioning. Your body is always using oxygen, but thinking in terms of which pathways are primarily being exploited at a given time can help us make better decisions about what training habits we should be cultivating.

All cellular work in the human body is performed with ATP (adenosine triphosphate). This molecule is cellular currency—the only currency cells can use to do any work. During a lift, our muscles need to perform a lot of work relatively quickly, which means the muscle cells need a lot of ATP. The phosphocreatine and fast glycolytic energy systems (i.e., anaerobic energy systems) are perfect for this situation. They can provide a huge amount of ATP to muscle cells, but the tradeoff is that they can only do so for a short time. After that, they need to recharge before another bout.

As ATP is used by muscle cells, creatine phosphate almost instantly replenishes the supply. This leaves creatine to be recharged with another high-energy phosphate back in the mitochondria—the home of aerobic systems. Fast glycolysis also produces ATP quickly, but the process is not sustainable. Large amounts of lactate result, and when these levels build up, glycolysis cannot continue until the lactate is dealt with. Aerobic energy systems process this byproduct to make another intense effort possible.

These aerobic pathways are at the other end of the metabolic spectrum, offering relatively slow ATP replenishment (and at lower levels) but for a virtually unlimited amount of time. Although this ability is not immediately helpful in the context of strength performance, these pathways are critical to restoring the conditions necessary for the next “anaerobic” training effort.

These different metabolic pathways are not independent of each other. They work together to provide the movements of life. The key point is that they need time to accomplish their task.

We need to rest between sets because aerobic metabolism is required to replenish anaerobic pathways. Aerobic metabolism needs around two minutes to begin providing that support. The total amount of time needed to be prepared for the next set depends on several factors: how intense the last effort was (how much ATP was used), how recovered you were from previous efforts, how skilled you are at grinding through reps while fatigued, how intense the next effort will be, and how prepared you want to be for the next effort (more on this later).

Rest in Practice

You can determine each of these factors for yourself quite easily. Take note of your respiration and heart rate before your workout begins. Think of this as your resting rate. After a work set, your respiration and heart rate will be elevated. For conventional strength training, you should rest long enough before the next work set that you return most of the way back to your resting rate (~90% recovered).

You could actually measure this, but that level of precision is not necessary. Within a few sessions, you will know what it feels like when you are close to your resting rate, but this will take at least three to five minutes.

The more advanced the lifter, the more deeply they will be able to deplete their anaerobic capacity, and this will require more time to replenish. Seven to ten minutes is not uncommon. That same lifter may take a little extra time before an especially challenging PR attempt, knowing they will need all the anaerobic capacity they can muster.

In contrast, warmups do not require any significant rest periods because they should not be fatiguing by design. If you find you require more than a short rest between heavy final warmups, you are probably not warming up properly.

Conditioning is a different story. When trying to challenge our aerobic capacity, we intentionally restrict rest periods so that anaerobic systems are not comfortably recharged between bouts of effort. For high-intensity interval training (HIIT), not resting more than two minutes per round is a good starting point. This same approach applies to hypertrophy work as well. If the goal is muscle failure (or close to it), restricting rest periods helps achieve that exhaustion.

Rest Period Habits

To the new lifter, rest periods may seem like a waste of time, but your body is not really resting between sets. It is feverishly working to replenish ATP in a relatively short amount of time. So, think about your breathing. Make sure you are utilizing all of your lung tissue during this aerobic phase of recovery. Remember, if you are moving around a lot during rest periods, your body now has divergent tasks to handle: ATP replenishment and motor performance. Don’t sabotage yourself! Allow your body to complete one task at a time.

Also, your brain is not resting. Your mental responsibility during training is technique execution, and rest periods are a perfect opportunity to review and critique the last set, formulate a plan for the next set, and focus on the cues and mindset needed to make that happen. If your form is decent, this might not require all of your attention, but this is still a good habit to maintain for when it is needed. Besides, is scrolling through social media that important?

Maximize Recovery on Rest Days

The most important point in this entire article is this: You do not get stronger from lifting weights. You get stronger as your body recovers from and adapts to your weight-lifting habits.

Lift too infrequently (or too little), and these sessions are not enough of a "disruptive" habit to force an adaptation. Lift too often (or too much), and your body will struggle to recover and adapt in time for the next insult. Both of these extremes are wasted effort, and neither will accomplish much beyond frustration.

Good programming will strike this balance, and an experienced coach can provide that for you. (Learn more about programming for yourself here.) But realize that how much stress you can recover from—and thus, how rapidly you can get stronger—is an ever-moving target that greatly depends on your lifestyle choices.

Simply put: Get as much restful sleep as you can, drink plenty of water, and eat high-quality foods as regularly as possible. (Learn more about nutrition here.) Moderate your alcohol consumption. Take care to manage mental stress at home and work as well. You should have an active, fun lifestyle, but don’t overdo it on rest days. If you help a friend move furniture the day before a heavy deadlift session, be prepared for disappointment in the gym.

If you struggle in any of these areas, you are not alone. It can be a real challenge for the modern adult to juggle all the responsibilities of life and take care of their health. But I would argue, ultimately, what else could be more important than being able-bodied and happy for as long as possible? I cannot think of a better priority to dedicate your efforts to.

Also, recognize that any shortcomings in lifestyle habits are merely technical obstacles. Strategies do exist that can make good habits easier to sustain. You can read about ways to improve your sleep quality here. Good nutrition habits are made much more convenient with meal prepping, for example. Younger adults can be bribed to help with physical labor for a surprisingly small amount of beer and pizza. Your options are truly only limited by your creativity and depth of research.

Mental health is beyond the scope of this article, but besides the more obvious religious and psychological resources, there are many ancient schools of thought (like stoicism) that are surprisingly relevant to the modern world. These approaches are particularly helpful because they focus on practical ways to deal with everyday obstacles so that stress doesn’t build up in the first place, regardless of the challenges a person faces.

Whatever strategies you employ, the key to their success is consistency. Remember that new habits get easier the longer you stick with them, so if something feels clunky at first, hang in there! Routines take time to develop, as does the body’s response to them. The human body thrives on predictable habits and schedules it can count on.

Resting is not a passive activity. It should be approached with the same procedure and ritual as the rest of your lifting routines because it can easily be the difference between a miss and maintaining progress. If you are grinding through reps or stalling—especially with novice programming—rest a couple of minutes longer and see if your performance improves. Be more deliberate with your sleep and nutrition on rest days. A simple change might be all that is needed to get back on track.