Answering all your questions about health trackers - AMA with CEO of Movitalis
Hi everyone!
I am the CEO of Movitalis, an activity tracker focused on longevity. I am here to make noise about my upcoming launch and provide as much value as I can in the process. While building this product I got to learn a lot about activity trackers, important and useless metrics, common mistakes and hidden gems. I've also learnt what the science has to say about these metrics and trackers, so if you have any questions, fire away! 🔥
I'll start with some things I learnt that are interesting and I wish everyone knew:
Tracking burnt calories during exercise is very inaccurate. All fitness trackers have a hard time estimating this value and studies show error margins up to 50%. This is because your calorie expenditure depends on things your tracker has no access to (how many calories you ate, how stressed you are, how is your metabolic health etc). Instead it's better to focus on calorie intake, and there are many good trackers such as Carbon Diet Coach 🍲
VO2 max is relevant for regular people too, not just athletes. In fact, it is probably more relevant for non-athletes since it is a better marker of health than performance and there is more variance between non-athletes than between athletes. In this study of over 1 million participants, a low VO2 max was linked with a 3-5x increase in overall mortality. This is an amazing finding as VO2 max is something we can increase through regular exercise, especially if done correctly. ❤️
Tracking daily steps is really simple but really valuable. There are many studies that show a strong correlation between daily steps and lifespan, but because it's such a simple (and maybe boring) metric we tend to overlook it. 🚶
Bonus: HRV is mostly irrelevant. Even pro athletes barely use this datapoint. Regular people are nowhere near the peak of their performance and most of us should not worry about being in the "optimal place" for training. We should just train and try to be as consistent as possible. 💪
Now if you have any questions, I'd love to know what they are and do my best to share what I've leant.
Thanks!
Replies
Product Hunt
What sleep trackers do you use? What are the metrics you think are most important? HRV is supposed to be important from a sleep standpoint, at least according to Eight Sleep... What did you think of Andrej Karpathy's comparison?
@rajiv_ayyangar Hi Rajiv! Honestly, I stopped tracking my sleep regularly, for 2 main reasons:
It does not inform what I do in the day any more than how I feel. If I have a workout planned I will do it, adjusting the intensity if I feel my body is just not keeping up. However, you usually only know that once you actually warm up and start the workout. I wouldn't listen to a poor sleep score if I actually feel well enough to do what I had planned.
After tracking for a while and (mostly) fixing my sleep hygiene, I realised at some point that I am not getting much more value out of each subsequent datapoint. Now I just focus on getting to bed at roughly the same hour, having enough time in bed and avoiding alcohol. Tracking does not add more signal at that point.
To answer your question however, I used to use an Apple Watch for sleep tracking (and still do occasionally). I had not seen Andrej Karpathy's post but had looked at The Quantified Scientist. Based on his experiments the Apple Watch performed pretty well, but not great. It does seem however that the Apple Watch has one of the best heart rate sensors as far as wrist devices go, which is great for the heart rate zones training I am doing.
Regarding HRV, I think it is useful for assessing how well you slept, determining your sleep stages and general readiness levels. It's a really interesting metric and can sometimes help you figure out if you are a bit sick or more tired than usual and can be a signal to take some more rest. But going back to my first point, I'd hate to miss a workout just because my watch tells me to take it easy (and I haven't seen anyone actually suggest that). The flip side of this is that most of us are over-stressed and under-slept, so taking more rest time if we can is generally always a good idea.
To sum up this info dump, I think focusing on good habits and having a consistent sleep and training schedule is the way to go. I also think we should focus on metrics that have less variance from one day to the other (such as VO2 max, strength, muscle mass using DEXA). They help us see the macro trend of our health better.
Hope this helps! Thanks for the question!
Product Hunt
@davidmanda "I'd hate to miss a workout just because my watch tells me to take it easy"
Yeah, it's one thing to track sleep and health in general, and it's another thing to figure out what to do about it. The recommendations piece is something that I think can be really personal and depends on your goals. For me, since I have goals I'm pretty committed to, when sleep quality is low, I usually try to find some ways to lighten the load a little bit or do an easier version of the workout, but I always calibrate based on how I feel after warming up.
@rajiv_ayyangar That sounds right to me. I think you might find the Movitalis app interesting and helpful for organising your workouts. I just launched today and I am so happy to have been featured. You guys really have quite the platform here, it surpassed my expectations.
Purposeful Poop
Don't have a ton to add, but appreciate your thoughtful answers and hope your project is a success! you clearly put thought into all this stuff, which im sure shines through in your app!
@catt_marroll Thanks Matt, I appreciate it! I hope so too. It launches tomorrow, so I am excited to see how the PH community receives it :)
Beyond the "normal" advice of eat clean, sleep good, work out frequently- what nuance or additional knowledge do you have about longevity specifically? Are there supplements or training regiments that move the needle?
@steveb Hi Steve, thanks for the question. Yes I do! I will focus my answer on the "work out frequently" part, as that is what my focus with Movitalis is. It's also the thing I know the most about and what will move the needle the most, after you get decent sleep and have a balanced diet.
The 2 main predictors of longevity are cardio, as measured using VO2 max, and Strength. When it comes to developing these 2 qualities, how you train makes a big difference. Specifically this is what you need:
For VO2 max:
Intense but relatively short and infrequent workouts that elevate your heart rate to 85-90% of your maximum achievable heart rate. One such workout per week is usually enough. Two if you are more advanced and have the time and energy.
Easy steady-state cardio workouts that are longer and more frequent. These build a strong aerobic base, increase metabolic efficiency and are easy to recover from. The ratio of easy to hard workouts should be roughly 80/20 (mostly easy, with some intensity. both are important)
For strength:
Intensity is key here as well. Taking sets close to failure and increasing your weights/sets over time is what gets the job done. Showing up is important, but it's not always enough.
The good news is that if you train hard, you don't need to spend that much time in the gym: 2 intense workouts/week can be enough. You can and should spend the rest of your available time just moving. Play a sport, go for walks, do some stretching. This way you'll be both strong and move well.
This is basically what Movitalis helps you do. It helps you follow this structure by analysing your workouts and automatically putting them in one of 3 categories (easy endurance, intense cardio or strength). It also creates a workout plan for you with this structure and shows you interesting data about your VO2 max.
Hope this helps!
minimalist phone: creating folders
How precise are all of those health trackers – e.g. calorie burners and those apps that reckon approx weight lost?
Because even when I do any activity, it doesn't count conditions (hot room vs cold environment which also affects burning calories).
Even the ratio of weight lost – was it fat, was it water?
@busmark_w_nika Hi Nika! Not very precise when it comes to calories burned - studies show that they usually overestimate and can be off by up to 50% in some cases. Some things that are actually pretty precise:
heart rate (chest straps, apple watch, garmin in this order)
VO2 max (not as accurate as a lab test, but in the ballpark)
steps