HIIT: Hack your Muscles, Happiness, and Creativity in One Go
Walking is man’s best medicine.– Hippocrates
The father of modern medicine had it right. You’re made of 360 joints, over 600 skeletal muscles, and more than 900 ligaments designed to keep you in motion.
You’re built to move, so it’s no surprise that your body rewards you when you exercise. A study of 10,269 men found that consistent moderate exercise decreased risk of death by 44%  and researchers have replicated these results in dozens of studies of both men and women .
Different kinds of exercise give you different benefits, and the two most popular types are resistance training and aerobic exercise. Here’s what the research says about both, as well as a guide to one of the best ways to work out.
For an in-depth plan on how to boost energy and increase brain function in just two weeks, get your copy of Head Strong.
Resistance training develops your brain, detoxes your body, and builds your physique
As the name suggests, resistance training puts your muscles up against a force that resists movement – think weightlifting, kettlebell training, and bodyweight workouts. Resistance training is typically brief and intense, driving your muscles to generate force from ATP stores instead of relying on oxygen. That brief, powerful stress to your system is great for you.
Resistance training makes your muscles stronger (surprise!) but it also taps into your brain so you move better. In a recent study, 15 men lifted weights for 14 weeks. At the end their muscles could generate more force, of course, but what’s more interesting is that their neural drive – their ability to send electrical signals from brain to muscle – also got stronger and faster . With greater neural drive comes more precise control of the way you move.
Resistance training detoxes your body as well. Your lymphatic system runs through your whole body, bathing your cells in a clear fluid called lymph. Lymph collects waste from your cells and clears it, but unlike blood, lymph has no organ to move it through your body. It relies on physical movement instead. One study found that 10-15 minutes of brief muscle contractions increased lymph flow by 300-600% .
Resistance training increases metabolic rate, keeping you in a fat-burning state . It also improves insulin sensitivity , and to top it off, the muscle you build will burn fat for you while you rest . That’s a three-pronged approach to burning more fat!
An excellent 2010 review of randomized, controlled studies showed that strength training decreases anxiety, boosts memory and cognition, reduces fatigue, and makes you happier .
Strength training increases bone density .
Strength training causes a sharp increase in testosterone and a 200-700% increase in human growth hormone, promoting muscle growth and fat loss in both men and women .
Resistance training sounds pretty good. What about endurance training?
Endurance training makes you smarter, happier, leaner, and more creative
Resistance training taxes your muscles in short, intense bursts, depleting your ATP stores; endurance training, on the other hand, taps into your aerobic system, relying on oxygen from your lungs to produce energy. Running, biking, swimming, dance – anything that keeps you breathing heavily stresses your aerobic system and tests your endurance, bringing a new host of benefits to the table.
Endurance training makes you smarter. It boosts brain-derived neurotrophic factor (BDNF), a powerful little protein that speeds up learning, increases memory, protects your brain from damage, and promotes neurogenesis (the growth of new brain cells). A randomized, controlled study of 12 men showed that three months of daily cycling nearly quadrupled resting BDNF levels . Resistance training also increases BDNF, but only in a short window immediately after exercise . Endurance training seems to boost BDNF more permanently.
Endurance training makes you happier, too. The runner’s high is real: moderate aerobic exercise improves mood, possibly in part by releasing feel-good endorphins [13, 14]. You don’t have to run until you’re blue in the face, either. 10 days of simple powerwalking was enough to significantly lessen symptoms in depressed people .
Endurance training decreases body fat more than resistance training does .
You even become more creative after a good bout of aerobic exercise. 31 men and women did either aerobic training or aerobic dance, and both groups showed greater mental flexibility and creativity afterward when compared to a third group that didn’t exercise .
Aerobic exercise also improves aerobic capacity by strengthening your lungs . No surprise there.
High-intensity interval training: the happy medium
Resistance and aerobic training are both powerful ways to hack your biology, and each gives a unique set of benefits. Why not combine them?
High-intensity interval training (HIIT) alternates between brief, strenuous exercise and active rest. You might sprint for 60 seconds, walk for 30, do push-ups for 60, walk for 30, and so on.
HIIT intensely stresses your muscles, then it lets them recover during active rest. Stringing exercises together and maintaining active rest keeps your heart and breathing rates up, so you also get the benefits of aerobic exercise. It’s the happy marriage of two schools of fitness thought. In fact, it may be more effective than either resistance or aerobic exercise alone. Remember that heavy resistance training increased human growth hormone (HGH) in men and women by 200-700% ? In one study, HIIT increased HGH by 2000% . Whoa!
The icing on the cake is that HIIT is efficient. There’s no need for an hour in the weight room and another hour running; you’ll be lucky if you make it past 15 minutes of HIIT when you first start out.
When you’re designing an HIIT workout there are a couple things to keep in mind:
Alternate between an exercise and active rest.
Don’t string together exercises that target the same muscle group. For example, don’t follow squats with lunges. Both target your quads, and you don’t want to tire your quads out and then tax them again immediately afterward. A good method is to alternate between upper and lower body exercises.
Set a timer instead of counting reps. Keep your phone at your side or an eye on the clock.
Keep good form!!! HIIT gets exhausting quickly. Exhaustion brings poor form, and poor form brings injury. If your form starts to slip, slow down or skip an exercise and do active rest instead. Listen to your body to avoid hurting yourself. If you’re unsure of good form, exrx.net is a useful resource.
Here’s a model HIIT workout to get you started. It doesn’t require equipment and you can do it just about anywhere.
Do each exercise for 60 seconds, and in between do active rest (walk in place) for 30 seconds.
Jog in place
Walk in place
Walk in place
Walk in place
Walk in place
Walk in place
Walk in place
If once through isn’t enough, repeat the workout until you’re spent.
You can also try a Tabata-style workout. Tabata workouts (named after their creator, Dr. Izumi Tabata, who used them in his research to great effect) follow a basic structure: choose an exercise and do 8 rounds of going all-out for 20 seconds and resting for 10. For example:
Burpees (20 seconds)
Rest (10 seconds)
Repeat 7 more times
Each exercise in a Tabata workout takes only 4 minutes. It’s harder than it sounds. Happy HIIT-ing!
6 Simple Habits To Build Stronger Joints
Humans are built to move. Your body thrives when you put it through physical challenges. Using the hundreds of joints and muscles that make up your biology keeps everything running smoothly.
That doesn’t mean you have to dead-lift 400 pounds or run a marathon. We’re not all Olympians. But in the modern world, it’s far too easy to sit at a desk all day, slowly losing your ability to move the way evolution intended. Muscles tighten, joints become brittle, cartilage starts to wear thin, and chronic pain sets in. Globally, 60-70% of adults in industrialized countries have chronic back pain . That’s not normal, and you shouldn’t accept it. My good friend Mark Sisson puts it well: “Live long, drop dead.” You can move like a well-oiled machine, free of pain, your entire life.
One of the keys is building resilient joints. You probably strengthen your muscles (if you don’t, here and here are two great ways to start). Strengthening your connective tissue doesn’t sound quite as sexy, but strong, flexible joints improve every aspect of your life. You’ll be more limber, leaner, stronger, faster, and more resilient to injury. And if you’re big into exercise, you’ll be amazed by how much more you can deadlift when your ankles aren’t tight, and how many pounds a flexible spine will add to your squat.
Here are 6 simple ways to build resilient joints. Pick whichever ones appeal to you, or try them all. Enjoy.
1) Walk more
Walk whenever you have the option. Walking compresses and decompresses your ankle and knee joints, sending your cartilage nutrients that keep it elastic. Walking also boosts your production of synovial fluid, an egg white-like substance that keeps your joints lubricated and prevents pain .
Take the stairs. Leave the car and stroll to work. Go on a hike with your dog. Go on a hike with yourself. Get out and move whenever possible, every day. It’s one of the easiest ways to keep your body strong. Bonus points if you turn your walk into a meditation.
2) Go barefoot
Or wear minimalist shoes, if your office isn’t too accepting of your biohacking habits. Cushioned heels shorten your Achilles tendon and change the alignment of your ankles . Stand up right now, barefoot, raise your heel a couple inches off the ground, and watch your calf muscle. You’ll notice that raising your heel shortens your calves, and that your knee comes forward to compensate, which pulls on your quadriceps, which pulls on your hamstrings, which…
You get the idea. An inch of padding under your heel may not seem like much, but when you compound it over thousands of steps a day for decades, you can see how a stacked heel pulls you out of alignment.
Barefoot walking and running, on the other hand, make your movements slightly more economical  and make you more resilient to injury . Running in minimalist shoes increases stabilizer muscles in your feet and improves arch structure, too .
But be aware: You can stress your joints during the transition from shoes to barefoot . Don’t go out and run 5 miles barefoot tonight, or you could injure yourself. Give your joints time to adjust to the larger range of motion. Start by walking around in minimalist shoes daily (it’s a perfect excuse to incorporate the first biohack on this list) and build your way up over a few weeks. Your ankles and knees will thank you in the long run.
Which shoes are best? I like my Vibram FiveFingers. If you want a more socially acceptable option, good old Chuck Taylors have zero-drop heels and are about $20. They may not give you the full benefits of a more minimalist choice, but they’re better than standard running or dress shoes.
3) Supplement with collagen and vitamin C
Collagen protein is rich in glycine, lysine, and proline, the three amino acids your body uses to make its own collagen . Vitamin C (in its ascorbic acid form) is an essential part of collagen synthesis, too. Pair high-quality, grass-fed, hydrolyzed collagen and ascorbic acid to stock your body with the building blocks it needs to build stronger joints. Your hair, teeth, skin, and nails become stronger, too.
4) Sit less
People who sit more die sooner . Plus, the more you sit, the more pain you’ll be in while you are alive. Sitting reduces blood flow, keeping precious nutrients from reaching your joints, and functionally shortens your tendons and ligaments, which puts more stress on your joints when you move. Sitting is especially bad for your lower back, hips, and knees. If you have pain in one of those areas, sitting less will probably help.
Okay. So stop sitting. That’s all well and good, but what if you work at a computer all day?
One option is a standing desk. I use one from StandDesk that alternates between standing and sitting modes at the press of a button. Pretty nifty. You can also just stack a couple boxes on your desktop until your computer rests at standing height.
If you don’t want to do the standing desk thing, set a timer to go off every 20 minutes during the work day. When the alarm sounds, stand up and shake your legs. Do a few squats or pushups. Stretch out. Dance like your puzzled coworkers aren’t watching. They already think you’re weird for putting butter in your coffee. Might as well add some office aerobics to the mix.
5) Stretch and roll out your muscles
If you’re doing heavy exercise without stretching, it’s only a matter of time before you injure yourself – especially if you’re sedentary for most of the day. Going from cold muscles right to CrossFit puts intense stress on your tendons and ligaments.
Take the time to stretch out and use a foam roller, or do yoga. All the shortened muscle fibers that have been sleeping while you stay still all day will wake up and start firing together. You’ll take stress off your joints, and you’ll perform better in the gym.
Kelly Starrett is one of the best mobility experts in the world. He has dozens of free videos showing you how to stretch/foam roll every part of your body. You can listen to him talk about mobility on Bulletproof Radio, too.
6) Use static back to realign your spine and posture
The static back pose uses gravity to realign your spine in 10 minutes a day. It places your shoulders in line with your hips to allow the muscles in your lower back to release, thanks to a combination of gravity and your own body weight. As your muscles release, the rotation in your pelvis and torso will also begin to fall into line.
How to perform static back:
Lie with your back on the floor, your feet and calves elevated on a chair, table, or blocks, with knees bent at 90 degrees. The backs of your knees should be flush with the edge of the block or chair so the legs are fully supported. This is the only you will be able to fully release these muscles.
Your arms should be in line with your shoulders, palms facing up.
Once you’re in position, take several full, deep breaths. No phones, no distractions. Take this opportunity to chill out.
Stay in position until your lower back and hips are settled flush with the floor. Or, you can set a timer for about 5 minutes. If your back and hips don’t settle to the floor, don’t worry. Just keep doing this for 5-10 minutes every day.
Spend a few minutes a day taking care of your joints. They’re an often overlooked part of your biology; strengthen them and you’ll improve every aspect of your physical performance. Thanks for reading and have a great week!
Biohacking Made Simple: 31 Small Steps to Becoming Bulletproof
Being Bulletproof is a mindset. It doesn’t mean overhauling your entire diet or drinking Bulletproof Coffee every morning. Being Bulletproof just means you’re working toward a stronger version of yourself.
Did you swap grain-fed meat for grass-fed meat? You’re Bulletproof.
Did you meditate this morning? You’re Bulletproof.
Did you walk 20 minutes today, instead of zero? You’re Bulletproof.
Change exists on a spectrum, and every little upgrade to your biology matters. Adopt one of the Bulletproof principles below, or adopt them all. Either way, you’ve taken a step toward bettering yourself and your life. You’re already Bulletproof because you’re reading this post. You’re on the path to becoming more awesome.
That said, the more you do, the better you’ll feel.
How to use this post
Below you’ll find 31 days’ worth of small steps to becoming a stronger, more resilient, more powerful you.
You can follow along, doing one hack every day, or skip the ones that don’t appeal to you. There’s no shame in passing on a day or going at your own pace – but again, the more you do, the better you’ll feel.
Use the hashtag #IamBulletproof on Instagram, Facebook, and Twitter so we can follow along on your journey to upgrading yourself.
31 Small Steps to Becoming Bulletproof
#1 Get your kitchen ready. Plan your attack for the month by giving yourself a day or two to prepare your kitchen. Clean out your shelves of cereal, bread, pasta, candy, sugar, factory-farmed meat, and vegetable oils. Then go out to the store and stock up on Bulletproof foods: high quality fats, plenty of vegetables, raw nuts, grass-fed beef, pasture-raised eggs, and wild-caught fish. Here’s a complete roadmap of which foods to eat and which ones to avoid. If you want to try Bulletproof Coffee for the first time, get the recipe and learn the science behind why it works, then pick up some Upgraded Coffee and Brain Octane Oil.
#2 Choose one thing to be grateful for. Gratitude is one of the simplest ways to build your happiness. Find something you’re grateful for today and write it down, keep it in the “Notes” app in your phone, or just take some time to think about it. Focus on the feeling it brings up in your body. Try sharing your gratitude with your partner or a friend. This way you can keep each other accountable and keep the practice going.
#3 Drink more water. Your detox organs – your liver, kidneys, and skin – depend on water to do their jobs effectively. Make sure to drink enough water to keep your body hydrated and working efficiently. Shoot for half your body weight in ounces. So if you’re 150 lbs., about 75 oz. is a good goal.
#4 Get up, stand up. The phrase “sitting is the new smoking” gets thrown around a lot these days. Research shows that it’s true – how much you sit is one of the strongest predictors of mortality. It tightens your muscles, slows your metabolism down, and drives high blood sugar and weight gain. Yikes. Today, make it a point to stand up every 20-40 minutes. Set a timer if you have to. You can also find a higher surface like a counter or some stacked books to create your own standing desk. Ditch TV tonight and take a walk, or do some crunches while you watch. Find even more ways to upgrade your workspace here.
#5 Replace morning carbs with healthy fat. Carbohydrates from bread, pastries, cereal, fruit, oatmeal, and sugary foods will sap your energy and lead to brain fog and inflammation. They’ll also send your blood sugar into a yo-yo, meaning you’ll crash around noon or the early afternoon. Fat, on the other hand, provides stable energy for hours and actually encourages you to burn fat. Start by removing carbs from breakfast and replacing them with fat. Try pastured eggs with avocado or some wild salmon. Or replace breakfast with a creamy cup of Bulletproof Coffee. Get the recipe here.
#6 Hug someone. Oxytocin, nicknamed the “cuddle hormone,” increases romantic attachment, social bonding, empathy, relaxation, and trust. It reduces anxiety, too. Getting a bump of oxytocin is easy. Today, hug someone for an uncomfortably long period of time. Women release oxytocin after a 3-second hug. Men release it after a 6-second one. Not sure who to hug? You can pet a dog instead, and you’ll both release oxytocin.
#7 Start foam rolling. Foam rolling is different than stretching. It breaks up knots in your muscles to restore normal blood flow and encourage oxygen and nutrient delivery throughout your body and into your cells. This will likely hurt, especially if you’re not used to it and work out a lot. Do it anyway and increase your range of motion and decrease pain! A little more on foam rolling here.
#8 Add some color to every meal. Brightly colored vegetables contain fiber and antioxidants that clean up the free radicals that contribute to chronic disease. Polyphenols found in brightly colored veg are particular potent. They fight free radicals and act as prebiotics, feeding good bacteria in your gut. Drown your veggies in grass-fed butter or ghee for some extra fat. Choose vegetables from this list in at every meal for increased energy and to keep your gut in good shape.
#9 Stretch out. Stretching can increase blood flow to healing muscles and can help prevent injury. Yoga (so much more than stretching!) has been shown to relieve chronic pain and decrease anxiety and stress, among other things. Find a local Yoga class or look up some stretching videos on YouTube. And check out this post on how to upgrade your Yoga practice!
#10 Get some sun. Sunlight stimulates vitamin D production, testosterone, blood flow, and feel-good dopamine. Sunscreen companies want you to believe that you should never go out in the sun without protection. In reality, sun-exposed skin actually has a far lower risk of cancer than covered skin. Sunlight is great for your skin, eyes, and mitochondria. The key is to get the right dose. Spend 10-15 minutes in direct sunlight today (and every day, ideally). Expose as much skin as you can without getting arrested. If you start to burn, you’ve gone too long. Scale it back by a couple minutes next time.
#11 Eat more fat. Fat from fatty wild-caught fish (sockeye salmon, for example), avocado, coconut oil, Brain Octane Oil, and raw nuts and seeds power your brain and support your hormones and mitochondrial function. Check out the Bulletproof Roadmap for a guide to which fats are good and which one will sap your energy.
#12 Go for a walk. Go for a 20-minute walk, or spend 5 minutes on a Bulletproof Vibe (if you’re in LA, you can use a Vibe for free at the Bulletproof Café and the LA Arts District Store). Walking will sharpen your memory and cognition. It’ll also loosen your muscles, strengthen joints, boost your metabolism, and circulate lymph to remove metabolic waste from your system. Your body is made to move. Oblige it.
#13 Get creative. Creativity is a skill, and it’ll grow if you make it into a habit. Creativity builds new pathways in your brain and strengthens your analytical thinking, too. Today, do something creative. It doesn’t have to be big or extraordinary. Draw, dance, write, sing, cook, plant a flower, play guitar, make up a new workout – whatever you enjoy. Whether you simply read a poem or pick up those old watercolors, engage your creative brain today in some way. This may lead to your next big idea or breakthrough at work.
#14 Black out your bedroom. Sleep is absolutely essential to functioning at your best. That doesn’t mean you need a lot of it, as long as you focus on sleeping better, not longer. Sleep is a critical time for tissue repair, detox, muscle and brain growth, and hormonal production. For better sleep tonight, cover your windows and turn off electronics so your bedroom is completely dark. You can use electrical tape to cover light that’s peeking through. For all the details on getting stellar sleep, check out this post.
#15 Trade conventionally raised meat for grass-fed. Grass-fed beef and grain-fed beef are two completely different foods. Grass-fed meat contains more antioxidants, omega-3s and other beneficial fatty acids, trace minerals, and vitamins than grain-fed beef. Factory-farmed beef contains added hormones and harmful fatty acid profiles that can make you sick and fat. Check out this handy infographic for the details on grass-fed vs. grain-fed.
#16 Relax and play. Most people work too hard these days. Block out time in your schedule to have fun: pencil a couple hours of relaxation into your day, and treat the time as seriously as you would a meeting. If you feel guilty about taking time off, remember that relaxing will make you far more productive, and look at your playtime as part of work. Chase your kids around the house. Take your dog to the park. Hike. Read. Do yoga. Try sensory deprivation. Meditate. Go for a drive with music cranked up and sing along. Whatever you do, enjoy it. Life is too short to spend your days working all the time. Caveat: zoning out in front of the TV doesn’t count.
#17 Upgrade your vocabulary. Eliminate the words “need,” “can’t,” “bad,” and “try” from your vocabulary. Weasel words limit you mentally.
#18 Change your brain with music. Certain kinds of music interrupt your brain’s response to distractions in your environment – people talking, web browsing, folks moving about the office – and help you to focus on the task at hand. Try a free trial of Focus@Will, a company that uses the science of sound to maximize your ability to concentrate.
#19 Get the biological benefits of a fast. Fasting can increase your lifespan, improve your lipid profile, make you more resilient to stress, increase mental clarity, and help you lose fat. [1,2,3,4,5,6] A spin on a traditional long-term fast is intermittent fasting – fasting for a short time without restricting your calories for the day. Eat all your meals in a 6-hour window today. The easiest way to do this is only eating between 2-8 PM, so you’re asleep for the majority of your fast. Make things even easier on yourself by trying Bulletproof Intermittent Fasting, which gives you the benefits of a fast without the hunger and crash.
#20 Work on your mobility. Pain isn’t normal. It’s your body’s way of telling you you’re doing something wrong, and you should probably listen. Mobility goes beyond traditional stretching. It involves soft tissue massage, dynamic movement, and strengthening exercises, too. Ready to get started with some functional movement? Try the Bear Walk and the Crab Crawl from this post.
#21 Breathe good air. Do you think about the air you breathe as nutrition? Indoor air may have mold, dust, industrial gases from furniture, and all kinds of other crap. Outdoor air is far cleaner. Go outside this morning and fill your lungs by inhaling deeply into your belly through your nose and exhaling slowly through your mouth. Better yet, work outside at a cafe today, if your job allows.
#22 Get rid of one of your possessions. Don’t let your things own you. Minimalism encourages getting rid of material goods so you can focus more on what matters – experience, family, friends, and whatever else brings you joy. But you can embrace minimalism without getting rid of all your possessions and living out of a backpack. Instead, only buy and keep the things that bring you joy long-term. Today, think of all the things you could trash, recycle or donate and commit to getting rid of at least one thing that no longer serves you.
#23 Strike up a conversation with a stranger. Exercise your social muscle. Do this especially if it freaks you out. Practice makes perfect, after all. If you aren’t sure what to say, ask a question or pay them a compliment. For more on hacking your social life, check out this post.
#24 Do a digital detox. Technology use – and social media use in particular – correlates strongly with depression and anxiety. Give up Facebook, Instagram, Snapchat, internet TV, video games, and all other technology for at least 24 hours, or for a full weekend. You might be surprised by how difficult it is at first. Power through; you’ll feel great after you do it a couple times.
#25 Make yourself uncomfortable. The only way to see what lies beyond your fears is to face them. Plus, being consistently comfortable puts you into a state of complacency. Start training for a Spartan race, take a cold shower, or try rejection therapy.
#26 HIIT it. HIIT (aka high-intensity interval training) alternates between brief, strenuous exercise and “active rest.” This might look like a 60-second sprint, followed by push-ups, followed by walking. Studies on HIIT suggest that this may be more effective than either resistance training or aerobic exercise alone. Plus, it’s efficient, offering the benefits of longer workouts in less time. HIIT is also amazing for your mitochondria. Check out this post for a sample workout and get moving.
#27 Deepen your connection with a loved one. The quality and quantity of your relationships affect your mental health, your behavior, your physical health – even your risk of mortality. Today, sit with someone you care about and ask each other some of these questions.
#28 Meditate. Today, start with just 5 minutes of meditation. Over time, work your way up to 10-20 minutes per day. Meditation relieves stress, boosts your immune system, eases anxiety and depression, and much more. It’s more important to be consistent than to meditate for longer. Opt for 5 minutes every day instead of 20 minutes a couple times a week.
#29 Throw away your multivitamins. Supplements are a double edged sword. The wrong ones can do more damage than good, but the right ones can massively improve your health, even if you eat a great diet. Check out this post for a step-by-step guide to nutrients that increase energy and performance.
#30 Take a cold shower. Cold showers are cryotherapy 101. This may sound excruciating, but the benefits are worth it. Cold exposure decreases inflammation, speeds up recovery, and can help you burn fat and sleep better. Start by blasting your entire body with cold water at the end of every shower. Try to work your way up to 30 seconds or a minute. If that’s too intense, try this workaround.
#31 Upgrade your brain. Nootropics – sometimes called smart drugs – are compounds that enhance brain function. They’re becoming a popular way to give your mind an extra boost. Today’s hack is to read this post and pick a smart drug to add to your supplement stack!
Congratulations. You made it to the end. Did you try something new? How did it feel? Did these small hacks inspire you to rekindle a lost habit? Share your story of how you’re becoming more Bulletproof in the comments below, or on Facebook, Instagram, and Twitter with the hashtag #IAmBulletproof.
You can subscribe below for more ways to upgrade your body and mind. Thanks for reading and have a great week!