Surprising Indicators of Longevity

Some measures that have been associated with longevity

Source

Thanks to the efforts of the likes of Peter Attia and co, most people are probably familiar with longevity, lifespan, healthspan and some of the testing around this. Broadly I think this is great, it means people are being mindful about their future and health decisions they are making in this context. Not to mention, engaging in healthier behaviours in general thanks to greater awareness.

Similarly, the increased awareness of these concepts has brought attention and limelight to testing associated with these outcomes (specifically longevity). Whilst some of these tests are more mainstream, I think many would be surprised by some of the other tests that track with longevity and lifespan - I know I was when I first learned about them all.

What Tests are Associated with Lifespan and Longevity?

Let’s start with my favourite scientific paper of all time, published in the December edition of the BMJ (where famously serious articles are presented in a more satirical/light hearted way for the holidays - scientists and doctors are a strange bunch). This specific article is titled; “How fast does the Grim Reaper walk?”, which perhaps unsurprisingly, discusses walking speed as a determinant of longevity or perhaps proximity to death. For those wondering how fast the the Reaper is, see below conclusion from the paper.

Conclusion: “The Grim Reaper’s preferred walking speed is 0.82 m/s (2 miles (about 3 km) per hour) under working conditions. As none of the men in the study with walking speeds of 1.36 m/s (3 miles (about 5 km) per hour) or greater had contact with Death, this seems to be the Grim Reaper’s most likely maximum speed; for those wishing to avoid their allotted fate, this would be the advised walking speed.”

VO2Max

This is probably the test most expected to see here, having recently seen a significant increase in popularity thanks to a plethora of health podcasts. Your VO2Max is the maximal amount of oxygen your body can use whilst exercising and usually requires maximal exercise whilst wearing a mask to analyse gases (oxygen and carbon dioxide) inhaled and exhaled. There are many websites and charts available with normative values for VO2Max given your age and biological sex which are all pretty good and I have linked to an article with values in the references too.

For those interested in an field test for VO2Max to estimate it, there is the possibility to do a ‘Cooper Test’ which is essence a maximal distance covered running in 12 minutes. Like many algorithms, this sort of test works fairly well as an estimate if you sit in the normal range of measures - I personally may see an inflated result given I have quite a low VO2Max and high running economy for example.

Leg Strength

Dovetailing in well with VO2Max and walking speed, leg strength rounds out the picture of functional capacity in many ways. Generally when people refer to leg strength, they are mostly referring to the quadriceps strength - partially because it’s a fair proxy, but also partially because it’s easy to measure in a research setting.

Functionally this looks like a leg extension test against a set up with a force transducer. That said, you could foreseeably use a leg extension max, but be weary especially if you don’t do much leg extension work, it is not risk free. Strength in movements requiring significant quadricep involvement is probably a good enough use for most people’s purposes (see conclusion for more on why), so in this case it may be a leg press (perhaps single leg), or squats at a push (you’re probably better off with a hack squat). The more technical and involved the exercise, the less it will allow people to truly display their strength.

For those looking for some standardisation of strength values across Kg to N this converter and table may help.

Grip Strength

In the sporting world and particularly in the strength training world, there is a phenomenon known as ‘dad strength’. We probably all intrinsically understand the concept, but in short (at least in previous generations) dad’s seemed to have this unbelievable strength without ever having specifically trained for it. In most cases a result of some level of manual work, even just tinkering with something of the sort. This often manifested most overtly in grip strength (calling dad to open jars anyone?).

Given the nature of strength; it manifests via us applying force to something, it probably stands to reason that our interface with the world would be a good proxy for overall strength and it turns out grip strength is exactly this.
*Foot strength also helps as the interface for the lower limb - see more here.

The references have some normative data for grip strength dynamometers, the best way to test this, though some do use a bar hang for time with a chinup bar. The target here being 2 mins or so (google is your friends for more extensive norms).

Single Leg Balance

This should be no surprise to subscribers given I have previously written about the benefits of balancing on one leg, falls risk and bone health and some aspects of proprioception, footwear and falls risk with respect to barefoot training.

Specifically, the inability to balance on one leg for 10 seconds is associated with all cause mortality - yes, dying from any cause, not just falls. Having said this, if you’ve had a fall, your chances of dying from any cause go up significantly too - you get there point here, cascading events, correlations etc etc.

Many readers are probably convinced they can do this fairly easily, and I’d suggest mostly this is true. What I would challenge readers with is to do this with your eyes closed (for reasoning, and other balance challenges see the ‘balancing on one leg’ hyperlink at the top of this section).

60 Second Max Pushups

This may be the most surprising measure of the lot, it is also the least publicised from what I have seen. This test is as simple as it sounds, designed for the doctors office it correlates well with cardiovascular health/risk of future cardiovascular events. For those with some understanding of physiology and training this would be somewhat surprising - it certainly surprised me and whilst we can rationalise it via some story such as correlating with BMI or something similar, let’s not waste our time and use the test like we do the rest; as an indicator of general physical wellness.

What I can say, though, is this test is not particularly pleasant, especially once you get to higher numbers.

Other Interesting Longevity Related Metrics

Calf Circumference

Granted the population is an older one, not to mentioned the results likely reflect a level of reduced functional capacity or disease related changes already, this recently published study on calf size did catch my eye (particularly as someone who’s not blessed in that region).
If you’re interested in testing I don’t think you need much more instruction that to use a tape measure, bend the left knee to 90 degree and the measure the broadest part of the calf (whilst relaxed).

Power

This article has largely avoided mechanisms, partially due to its nature but also partially due to an upcoming article talking about declines in physiological capacities with age and detraining (spoiler alert: I think some of the decay rates we use are overstated).

That said, in this case is worth touching on quickly. In short, as we age we end up effectively moving towards muscle more suited to endurance type activity than explosive type activity. This has spawned a new scientific term to go with sarcopaenia (low muscle mass), that being powerpaenia.

Normative values for power are below in the reference list, with my preference being a vertical jump but horizontal jumps are certainly an option (again, google is your friend for data but roughly your own height is a good rough goal). This link should help
converting vertical jumps to force.

Fundamentally, all these tests are telling us something very similar: how well the organism is functioning. Yes, they all test something different, yes addressing areas of weakness/need is a great way to spend/budget your resources (time, money, effort etc) but fundamentally they reflect a good set of inputs. They are unlikely a challenge to many of the younger readers, or at least good results are probably attainable with pretty low output for these folks but the key here is to understand what the data are telling us: live a life conducive to these measures being high when old.
Oh and never forget Goodhart’s law with this sort of thing; “When a measure becomes the goal, it ceases to be a good measure”.

References:

1. Fiona F Stanaway, Danijela Gnjidic, Fiona M Blyth, David G Le Couteur, Vasi Naganathan, Louise Waite, Markus J Seibel, David J Handelsman, Philip N Sambrook, Robert G Cumming. How fast does the Grim Reaper walk? BMJ 2011;343:d7679 doi: 10.1136/bmj.d7679

2. Strasser B, Burtscher M. Survival of the fittest: VO₂max, a key predictor of longevity? Front Biosci (Landmark Ed). 2018 Mar 1;23(8):1505-1516. doi: 10.2741/4657. PMID: 29293447.

3. Karampreet Kour Buttar et al., Normative Data of Maximal Oxygen Consumption (VO2 Max) in Healthy Young Adults. July 2022. Journal of Clinical and Diagnostic Research 16(07) https://www.jcdr.net/articles/PDF/16672/53660_CE[Nik]_F(SHU)_PF1(AG_SHU)_PFA(AG_KM)_PN(KM).pdf

4. Anne B. Newman, Varant Kupelian, Marjolein Visser, Eleanor M. Simonsick, Bret H. Goodpaster, Stephen B. Kritchevsky, Frances A. Tylavsky, Susan M. Rubin, Tamara B. Harris, on Behalf of the Health, Aging and Body Composition Study Investigators, Strength, But Not Muscle Mass, Is Associated With Mortality in the Health, Aging and Body Composition Study Cohort, The Journals of Gerontology: Series A, Volume 61, Issue 1, January 2006, Pages 72–77, https://doi.org/10.1093/gerona/61.1.72

5. Bohannon RW. Grip Strength: An Indispensable Biomarker For Older Adults. Clin Interv Aging. 2019 Oct 1;14:1681-1691. doi: 10.2147/CIA.S194543. PMID: 31631989; PMCID: PMC6778477.

6. Massy-Westropp NM, Gill TK, Taylor AW, Bohannon RW, Hill CL. Hand Grip Strength: age and gender stratified normative data in a population-based study. BMC Res Notes. 2011 Apr 14;4:127. doi: 10.1186/1756-0500-4-127. PMID: 21492469; PMCID: PMC3101655.

7. Yang J, Christophi CA, Farioli A, et al. Association Between Push-up Exercise Capacity and Future Cardiovascular Events Among Active Adult Men. JAMA Netw Open. 2019;2(2):e188341. doi:10.1001/jamanetworkopen.2018.8341

8. Araujo CG, de Souza e Silva CG, Laukkanen JA, et al. Successful 10-second one-legged stance performance predicts survival in middle-aged and older individuals. British Journal of Sports Medicine 2022;56:975-980. https://bjsm.bmj.com/content/56/17/975

9. Fernandes DPdS, Juvanhol LL, Lozano M, Ribeiro AQ. Calf circumference is an independent predictor of mortality in older adults: An approach with generalized additive models. Nutr Clin Pract. 2021;1–9. https://doi.org/10.1002/ncp.10780

10. Freitas SR, Cruz-Montecinos C, Ratel S, Pinto RS. Powerpenia Should be Considered a Biomarker of Healthy Aging. Sports Med Open. 2024 Mar 25;10(1):27. doi: 10.1186/s40798-024-00689-6. PMID: 38523229; PMCID: PMC10961295.

11. Coelho-Junior HJ, Marzetti E, Picca A, Tosato M, Calvani R, Landi F. Sex- and age-specific normative values of lower extremity muscle power in Italian community-dwellers. Journal of Cachexia, Sarcopenia and Muscle 2023;https://doi.org/10.1002/jcsm.13301