I recently had the pleasure of interviewing my friend and business and training partner Brad Kearns for the upcoming Primal Endurance Online  digital course (more about that later). It was more of a discussion, really, and we kept coming back to the same three elements for constructing any successful training program. I’m going to present them as they came to me—as bullet points, as tangentially related thoughts. Then I’ll expand on them from there.
Without further ado…
You don’t really need to train the heart to beat faster. The heart easily responds to exercise stress by elevating rate and stroke volume, even in an unfit person walking up the staircase! Anyone who’s ever had to speak in public knows that your heart rate jumps up to 150 BPM 10 minutes before its your turn without you doing anything overtly physical. The heart knows.
Of course, that doesn’t mean you shouldn’t do hard stuff. You can train the heart to withstand greater demands and you can increase lung volume as well by doing very specific, strategically placed high intensity workouts (sprints , intervals, tempo runs). But when you train the heart “hard” you do it sporadically, not every day, not even more than once or twice a week. We used to think you trained the heart at high heart rates every day , or several days in a row, to get the cardio part dialed in. We know now what’s more important is focusing on the biochemistry and energy production at the level of the muscle cell. And to dial that in, we must engage in copious amounts of low-level aerobic activity at or below the 180-minus-age fat-burning heart rate zone to build more mitochondria . The more mitochondria you build  at the muscle site, the more efficiently you produce energy, and the less you have to rely on your heart pumping faster and harder and in so doing risking all the fallout (high stress hormones, decreased immunity, burnout, injury, etc). With more available mitochondria turning fuel into energy, each pump is more efficient.
You don’t need to train the brain to suffer. The brain will be ready to suffer when it’s asked to. This is the fight or flight response after all.
Suffering is overrated.
We’re set up to respond to stressful situations with a flood of hormones that support and enable a suitable response. Those responses are hard wired in us, which is why you hear about the 130 pound mother lifting the back end of a station wagon off her kid, the man rushing into the burning building to save someone without thinking, the newbie conscript performing medal-worthy acts of bravery on the battlefield. They didn’t train for those specific situations. They rose to the occasion. Those responses don’t go away because we don’t train them three times a week.
And if you’re not competing, why suffer?
I get climbing Mt. Shasta with your pals on a long weekend. I understand running the ultra, or going for a deadlift PR, or doing a Spartan Race, or slipping on your own sweat on the final rep of the CrossFit WOD. Those quiet feats of elective heroism are important in a safe, sterile world that no longer demands we place ourselves in mortal danger just to survive. To feel human, to feel alive, we need to overcome obstacles, even if we have to erect them ourselves.
Just save the suffering for those heroic efforts. Save it for the race. Training shouldn’t cause suffering, only discomfort. Training shouldn’t simulate competition.
After you build the aerobic base, all that’s left is to train the muscles to perform the desired activity: run a fast 5k, a slower marathon, or perform well at the Crossfit Games.
First you build the aerobic base—or actively pursue it—and then you train your muscles for the desired activity.
As it turns out, skeletal muscle fiber physiology dictates this training approach. There are two primary types of muscle fibers: slow twitch and fast twitch. Slow twitch muscles aren’t very exciting. They contract slowly, making them perfect for aerobic, everyday activities like walking, controlling your posture, standing up from a chair, gardening, shopping. Anything you do without being out of breath utilizes slow twitch fibers. Fast twitch muscles contract quickly and are used to perform high-intensity, explosive movements like sprinting, jumping, throwing, and lifting. Some of us have more fast twitch muscle fibers than others, while others trend toward slow twitch dominance, but the fact remains that everyone has and needs both types.
Slow twitch fibers recover faster than fast twitch fibers, which is why we should walk but not sprint every day, garden but not squat heavy every morning, and do housework but not run a 5k daily. This physiological reality—that sans external aids slow twitch fibers can handle more frequent utilization—underpins Primal Blueprint Fitness and Primal Endurance. A ton of slow easy movement (walks, hikes, light runs) interspersed with infrequent bursts of intense activity (strength training sessions, sprinting, CrossFit workouts, race-pace runs) really does get you stronger, fitter, and faster while allowing ample recovery for the muscle fibers used in each session.
Training those slow twitch fibers through aerobic base-building isn’t only for endurance athletes. When you build a base, your cardiovascular system will grow and adapt and become more efficient at shuttling blood and oxygen to your tissues, aiding in recovery and performance. Your muscle fibers will have more mitochondria willing and able to do their bidding, and any type of training becomes more fruitful, more productive, and easier with more cellular power plants at your disposal.
That’s why the aerobic base is so crucial: it builds those mitochondria that power your efforts and turn fat into fuel.
Sprinters need  an aerobic base.
Lifters need an aerobic base.
CrossFitters need an aerobic base.
To get the aerobic base, you need to take it easy. Go slow and go long. I’ve said it before and I’ll say it again because people never believe me: make your long workouts longer and easier.
I can already sense the emails coming in: what about breakthrough workouts? According to the post I wrote on breakthrough workouts , there’s real value in pushing past the sticking point, in going harder, farther, and faster than you ever have before. Breakthrough workouts are extraordinary efforts that produce psychological and physical training effects, building mental and muscular toughness with lasting benefits for your performance.
But breakthrough workouts are few and far between by design. They only work when laid atop a foundation of regular, consistent training sessions.
But the pros, Sisson! The professionals aren’t taking it easy! They’re leaving it out on the track/in the weight room/on the court/etc every single day. Right? The pros do a lot of things wrong. They get away with it because they’re the pros. They often have superior genetics that allow quicker recovery and resistance to injury. They “know” their way is correct because it’s how everyone who came before them have always done it. They’ve also got their egos to contend with—the need to be tougher and put in more miles every week than the other guys. Doesn’t mean it’s optimal. There’s little doubt in my mind that the ultra-marathoners I know who insist on doing all-day hard runs every weekend in preparation for the Western States 100 (a 100 mile ultra run through the Sierras at the end of June that draws the best of the best) would be better off sleeping in and doing an easy longish jog 3/4 of the time.
Besides, the professionals are coming around  to smarter, more sensible training.
I agree with Phil Maffetone, who thinks that the path to a 1:59 marathon  will be a counterintuitive one: once the elites start training less and going easier, they’ll break the record. Ego is a mighty dragon.
It’s time to slay it.
So I’ll end with an ask. I want everyone to try something new and a little counterintuitive the next time they have a hard workout session:
Quit while you’re ahead. Cut it in half. Drop the weights. Don’t finish the WOD.
Keep up the intensity. Go hard. Just not for so long.
If you’re running hill sprints, don’t go till you puke. Leave a little in the tank.
If you’re mentally preparing for a CF WOD after you get off work, maybe Fran , maybe AMRAP clean-and-jerks of varying weights in 20 minutes , plan to cut the session in half.
If you’re doing a tempo run in preparation for a race, maintain the pace but cut the distance in half. Don’t run a facsimile of the race.
What you notice is that cutting your hard workouts short end up making them harder, more intense, and—wait for it—more effective. You lift heavier weights, and the reps feel more smooth. You run at race pace for thirty minutes instead of the hour you’d do otherwise, and you get the training effect without the cortisol cascade that impairs you for days afterward.
Try that and let me know what you think.
Thanks for reading, everyone. Take care!