@chamath Great insight from your scans. Prenuvo folks use Spren to track body composition monthly between MRIs - continuous data makes it way easier to see if your training/nutrition is actually moving the needle on muscle mass.
DEXA scan = $200-$300
Spren app for iPhone = 1st scan free
Same accuracy on body fat % reading (3rd party tested)
It’s insane how far technology has come
Super interesting data here -
The 1st pic is my current condition post workout.
I was curious as to what my body fat % was, so I did a scan on my phone with Spren.
(Spren is an IOS app that gives you a body fat % reading with the accuracy of a DEXA)
I was guessing 12%.
Spren has me at 14.9%.
Which one do you think is more accurate? My guess or the Spren scan?
There’s some extra info there too - it’s crazy you can get this level of detailed analysis with just your iPhone camera.
Highly recommended if you’re into fitness and health.
@anymanfitness I've learned a ton from @anymanfitness about this, and we're honored to partner with him.
He's put so much knowledge and experience into his AI: https://t.co/NEK8agbrUo
Also happy to help if anyone has questions! (I'm the CEO of Spren)
@anymanfitness Seen this happen so many times! People use a macro calculator and then fail to adapt it to their body and their situation and wonder why it worked for someone else but not them.
There's a lot of nutrition advice that gets spouted as gospel, but is overly simplistic.
"1 gram of protein per pound of bodyweight" is a prime examples of this.
So is "eat at a 500 calorie deficit every day".
Sure, these sound bites make things simple, but is that actually going to work best for you?
Example - take 2 guys who are both:
- 180 pounds, 5'10" and 20% body fat
- Lift weights regularly
- Sleep 7+ hours/night
- Track all their food
Guy #1 decides to diet and goes with:
- 180 grams of protein
- The rest evenly split between carbs/fats
- 500 calorie deficit/day
He goes with all the "Twitter recommendations" he hears.
Guy #2 does a body fat scan with @sprenlabs and realizes he has 145 pounds of fat free mass.
So instead of a Twitter blanket recommendation, he goes with:
- 145 grams of protein
- The rest evenly split between carbs/fats
- Uses a more moderate 350-400 calorie deficit/day
They both burn around 2800 calories per day.
Guy #1 has macros of:
180 protein / 195 carbs / 87 fats
Guy #2 has macros of:
145 protein / 233 carbs / 103 fats
So, who is going to be more successful with his diet?
Some would immediately say Guy #1, just because he has more protein.
But is that really true?
Protein is important, don't get me wrong - but it's not the end all be all.
With more energy to power through his workout, and more fats/carbs to enjoy (and a slightly lower deficit), in many cases, Guy #2 comes out on top.
Guy #1 has a bigger deficit.
He has less fuel (carbs) for his workout.
He could easily end up flaming out and crashing.
Guy #2 is properly fueled up, and ends up having better lifting sessions.
He's fueled, energized, and burns more calories as a result.
His diet is more sustainable, more enjoyable, and he ultimately has better long term progress.
Getting a pinpointed, personalized plan of attack based on your own body fat % is always better than randomly following a guideline you see on X.
This is why I'm so bullish on both the Spren app, and the AI coaching option I've created with Spren.
Spren is an iOS app that reads your body fat % with the accuracy of a DEXA scan (3rd party tested).
DEXA scans cost hundreds of $$$ for just one.
With the combo of 'AI Coach J' and Spren, you get:
- Unlimited body fat scans
- Personalized nutrition goals for your metabolism
- 24/7 support from 'AI Coach J'
- Grocery lists, meal plans, workouts, daily motivation
- Answers to any question under the sun you have via the AI
Plus, the AI is trained to speak and act just like me. I swear that's a good thing (LOL).
It uses my teachings, philosophies, strategies, etc that I've used to help thousands get into the best shape of their lives over the last 12 years.
Look at the comparison:
- 1 DEXA scan:
$300+
- Unlimited body fat scans, personalized nutrition, AI coaching, 24/7 support and help, workouts, recipes, and anything else you need:
$90 for 3 months
Hell, if you're fitness oriented, this is worth it for just the unlimited body fat % scans alone.
As you make progress, lose fat, and gain muscle, your program will be adjusted as needed to keep the results coming to you as well.
GAME. CHANGER.
To learn more, just shoot a text to 734-499-1101 if you're in the US.
Use What's App (same #) if you're outside the US.
Summer is coming.
Let's get it.
If you want to meaningfully impact aging in America, start with obesity—few things erode longevity and quality of life as profoundly, accelerating the biological aging process and fueling nearly every major chronic disease.
Obesity alone is linked to 13 types of cancer and cuts life expectancy by 3–10 years, depending on severity. It promotes DNA damage and accelerates our fundamental aging process—often measured by epigenetic age. It’s one of the principal differences between the U.S. and many of the world’s longest-lived nations.
We’re overfed but undernourished. 60% of all calories Americans consume come from ultra-processed foods that:
• Fail to induce proper satiety, pushing us to overeat.
• Remain cheaper than whole foods, economically incentivizing the least healthy choices.
• Hijack our dopamine reward pathways, reinforcing addictive eating behaviors.
This trifecta—no satiety, low cost, and built-in addictiveness—keeps us in a cycle of poor health outcomes and runaway healthcare costs.
But caloric excess is only part of the problem—we are also nutrient-deficient.
Low omega-3 levels—affecting 80 to 90% of Americans—carry the same mortality risk as smoking. Vitamin D deficiency—easily corrected—compromises immune function, cognition, and longevity. Nearly half of Americans don't get enough magnesium—impairing DNA repair and increasing the risk of cancer.
We are not solving these problems—we are medicating them. The average American over 65 takes five or more prescription drugs daily—stacking interactions that compound in unpredictable ways.
We must start treating physical inactivity as a disease. It carries the same mortality risk as smoking, heart disease, and diabetes. Going from a low cardiorespiratory fitness to a low normal adds 2.1 years to life expectancy.
By age 50, many Americans have already lost 10% of their peak muscle mass. By 70, many have lost up to 40%.
This isn’t just about looking strong. It’s about survival.
• Higher muscle mass means improved insulin sensitivity - it means a 30% lower mortality risk.
• Grip strength is a stronger predictor of cardiovascular mortality - the number one cause of death in the United States - than high blood pressure.
• The strongest middle-aged adults have a 42% lower dementia risk.
And yet, we treat resistance training as optional. It is not. It is the most powerful intervention we have against aging including increasing muscle mass, strength and bone density.
Hip fractures alone kill 20–60% of older adults within a year. This is a death sentence we can prevent with resistance training - which has been shown to lower fracture risk by 30-40%.
The current RDA for protein is too low for older adults.
Studies have shown when it's increased by half this reduces frailty by 32%, while doubling it, combined with resistance training, increases muscle mass by 27% and strength by 10% more than training alone. If we want to prevent muscle loss and frailty, we must update our protein recommendations and prioritize strength training.
We must foster a culture of American exceptionalism built on daily, effortful exercise. Not as an afterthought. Not as a luxury. But as a non-negotiable foundation for aging, but also clear thinking, resilience, and even leadership.
The body and brain are not separate. The consequences of poorly regulated blood sugar, sedentary living, and muscle loss are not just physical—they affect cognition, judgment, and resilience.
We cannot medicate our way out of what we have behaved our way into.
Grateful for the chance to share my voice at the Senate Aging Committee (@SenateAging). A special thank you to Senator Rick Scott (@SenRickScott) for making this opportunity possible.
Spren is one of the most impressive things I’ve seen in fitness tech.
Once the gen pub realizes they can get DEXA accurate scans with their iPhones they will explode onto the scene.
@sprenlabs
Hey - if you'd like to check out the live webinar I did last week with the CEO of @sprenlabs (@thehumanjason), here's the link!
We had a great talk and covered lots of fitness and business topics.
https://t.co/JlXvJ1nBKj
People who exercise and use the sauna can experience a synergistic health benefit—with a nearly 70% reduction in mortality risk among fit frequent sauna users.
Research also shows that adding sauna to the tail end of your aerobic workout can have incredible benefits for heart health, VO2 max, and endurance performance.
Runners who used the sauna for 20 minutes after aerobic exercise training enhanced their VO2 max by 6% and endurance performance by 12% compared to exercise training without the sauna. Their blood pressure and cholesterol even improved.
Not only did post-exercise sauna bathing lead to better exercise performance in the heat, but it also improved the runners' performance in moderate conditions, suggesting that the benefits occur regardless of the environment.
The minimum effective dose is 2 times per week for 20 minutes at a temperature of 175 degrees Fahrenheit or more. Do it as close to the end of your training session as possible to maximize the benefits.
You can learn more about the benefits of sauna for aerobic and resistance training in the latest episode of the Found My Fitness podcast, where @brady_h and I distill expert advice on how to train.
Link to episode on YouTube:https://t.co/PCn7Eq6KiA
REMIDNER:
Tomorrow I'll be co-hosting a live webinar with Jason Moore (@thehumanjason), the CEO of Spren (@sprenlabs), a body fat testing app for iOS I've partnered with to create a cutting-edge AI based coaching option.
The webinar is at noon, Eastern Time zone.
If you register and can't make it then, a recording will be sent to you via email!
We will be discussing:
- My own fitness journey into becoming a Coach/owner of a fitness business
- My coaching philosophies and how I help clients
- My partnership with Spren, and how AI based coaching works
And much more - hope to see you join us!
Link in the next tweet to register!
@FitFounder People consistently over estimate their muscle and under estimate their body fat %.
Good news: Being bad at self-estimating isn't anything to be ashamed of. Once you know the reality, you can improve it! :)