Fitness Toolkit: Protocol & Tools to Optimize Physical Health

The episode opens with the host, who introduces himself as Andrew Huberman, a professor of neurobiology and ophthalmology at Stanford School of Medicine, setting out the subject: fitness as a driver of cardiovascular health, strength, endurance, lifespan and healthspan. He acknowledges that the amount of fitness information available online and in books "can be a bit overwhelming," and frames the episode as a synthesis of science-based tools covered earlier on the podcast, including conversations with Dr. Andy Galpin, Dr. Peter Attia, movement specialist Ido Portal, and physiotherapist and strength and conditioning coach Jeff Cavaliere.

He also announces a change in format. Usually the show presents mechanisms first and protocols second. This time he leads with one specific protocol meant as a general template for endurance, strength, flexibility, hypertrophy and aesthetic changes, which listeners can then customize. Someone focused on strength or muscle size can shift the program that way. Someone who wants to hold strength while building endurance can do that instead. He promises to address practical questions too, such as whether to train while sleep deprived and whether to train when hungry or unfed.

He presents the template as one he has used himself for more than three decades. He says he recently turned 47 and adjusts the template to his goals for a given year, month or even day. He stresses that the plan has to survive real life, including travel, missed workouts, and weeks that do not go the way the plan on paper assumes. He says the template draws on peer-reviewed studies and on the experts who have appeared on this and other podcasts.

Before the main protocol, the host describes a new study from the University of Houston that he calls "very exciting and frankly, very unusual." It was published in iScience under the title:

A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation.

The study centers on the soleus, a wide, flat muscle beneath the gastrocnemius that forms part of the calf. The host explains that the soleus is made up largely of slow-twitch fibers and is built to contract continuously for standing and walking. He says a person could walk all day on it and "most likely it would not get sore." He contrasts this with the biceps or triceps, which would eventually fatigue and burn after hundreds or thousands of repetitions, even with a one- or two-pound weight.

To explain why the findings matter, he gives a simplified account of blood glucose regulation. Blood glucose rises after eating, and insulin helps manage it. The aim is for glucose to rise after a meal, but not too high and not for too long. He contrasts hyperinsulinemia with hypoglycemia. He describes type 1 diabetes as a condition in which people do not make insulin and must take it, because otherwise glucose can rise high enough to damage cells and organs and "can even kill people." He describes type 2 diabetes as insulin insensitivity: the body makes insulin, but the receptors respond poorly. He flags that this account is "very simple" and points to earlier episodes for a fuller treatment.

The study's movement is the "soleus pushup." The person sits with the knee bent at roughly a right angle, lifts the heel while pushing down through the toe, lowers the heel, and repeats. The host describes the sample as equal numbers of male and female subjects, with a wide range of body mass indices, ages, times of day, and walking habits. Participants did the movement while seated in the laboratory for up to 270 minutes in total over the day, about four and a half hours, with breaks. They did not contract the muscle hard. The heel rose 10 to 15 degrees, not all the way onto the toes.

The host reads from the abstract. Muscle glycogen measurements showed very little fuel use within the soleus. Even so, the researchers reported "52% less postprandial, that's after a meal, glucose excursion" and 60% less hyperinsulinemia, along with "big improvements in systemic metabolic regulation." He adds that the benefits lasted: improved glucose utilization was still visible as long as two hours after a meal.

He qualifies these results in several ways. He calls the findings "pretty miraculous, almost hard to believe," but says he believes the data, which look well collected and statistically thorough. He notes that, to his knowledge, the work has not been replicated. He says he could not find in the methods whether participants were doing soleus pushups while consuming the glucose. His view that fewer than 270 minutes would still help is his own reading of the effect sizes, not a result the study tested.

I'm not aware that anyone's replicated this study yet.

He presents the movement as an addition to exercise, not a substitute: "please don't stop exercising the other ways that you exercise." He suggests it may suit people who are injured, stuck on a plane, sitting in class or in meetings, or short on steps, as well as people who already exercise and want more metabolic benefit. He calls it zero cost and low investment. Its main cost is attention, since it takes some focus to keep doing the movement. He also says he is not suggesting people focus on soleus pushups constantly throughout their lives.

Turning to the main topic, the host borrows a principle from his conversation with Dr. Andy Galpin: "concepts are few, methods are many." There are countless programs, set and rep schemes, and exercises, but only a few underlying principles of muscle physiology, cardiovascular function and connective tissue function drive the adaptations people call fitness.

He lists the adaptations a program might target:

Skill Speed Power, described as speed times strength Strength Hypertrophy, or muscle growth Muscular endurance, such as holding a plank or a wall sit Near-pure anaerobic endurance, such as an all-out sprint or stationary-bike effort of one minute or less Endurance in the roughly three- to 12-minute range, such as high-intensity intervals or an all-out swim or row Endurance lasting 30 minutes or more

Each of these needs different principles to improve. Underneath all of them, he says, is a shared question taken from Galpin: what are the modifiable variables? Progressive overload is one key concept. He widens it beyond adding weight to a bar to include running a steeper hill, running a little faster, or running a little farther. He says he will not go back through the mechanisms covered in the earlier expert episodes and refers listeners to those episodes for detail.

The protocol starts by trying to develop all aspects of fitness "to the extent that you can simultaneously maximize all aspects of fitness." It can then be adjusted, for example to build strength while only holding onto existing endurance, or the reverse. The host says he believes most people want a mix of strength, endurance, flexibility and some hypertrophy, perhaps for lagging muscle groups. Their reasons may include aesthetics, health, general function, and possibly reducing pain.

The design focuses each day on one aspect of fitness, such as endurance, strength, or hypertrophy for particular muscle groups. Across the whole week, it covers the whole body and several forms of fitness. He is careful to say the protocol's value does not come from the fact that he uses it: "this protocol is not important because it's the one that I follow. I follow it because it is important." He describes it as drawn from the scientific literature and the experts, and says he refers to his own use only for ease of communication.

The week begins on Sunday, though the host notes this is just the day he happens to start. That day's workout targets endurance of 30 minutes or more. His aim is 60 to 75 minutes of jogging in what is called Zone 2 cardio. He defines Zone 2 practically: breathing and heart rate are elevated, but you can still hold a conversation. Pushing any harder would cost you the ability to finish sentences. A heart rate monitor can measure it but is not required, and he does not wear one for this workout. He also says it is "near impossible" to stay exactly in Zone 2 without a lot of skill, so he does not obsess over it.

Jogging can be swapped for rowing on a machine or in a boat, cycling, or swimming, as long as the movement is continuous for 60 to 75 minutes at that threshold. On steep hills, he slows down to stay roughly in range. On gentler grades, he may slow slightly or push a little. The goal is to build or maintain the capacity to go a long distance without fatiguing.