Still Pedalling at 80: Lifelong Cyclists Still Age but Stay Far Ahead

King’s College London researchers re-tested 82 of 125 highly active amateur road cyclists nine years after their first assessment, now aged 64 to 86. Aerobic capacity (VO2peak) fell by 19.7%, about 2.2% per year, which is faster than cross-sectional studies predicted. Lean mass fell 8.1% and fat mass rose 20% while body weight stayed flat. Blood pressure, glucose and lipids stayed normal, and 77 of 78 testable participants remained at or above the 90th percentile for fitness for their age. Only 35 of 82 stayed disease free. Twenty-three developed poorly controlled disease, almost all cardiovascular. This group lost somewhat more fitness but still stayed near the top of the population range.

In 2012 and 2013, researchers at King’s College London put 125 amateur road cyclists aged 55 to 79 through a large battery of physiological tests. The goal was to study aging with inactivity taken out of the equation. Most older adults do too little exercise to meet national guidelines, so it is hard to tell which losses come from time and which come from the sofa. People who could still ride 100 km in under six and a half hours were meant to show what aging looks like when the body stays in use.

Nine years later the team called everyone back. Eighty-two returned, and every one of them was still cycling. Their aerobic capacity had fallen from 44.1 to 35.4 millilitres of oxygen per kilogram per minute. That is a drop of nearly 20 percent, or about 2.2 percent a year. The rate is roughly two and a half times what cross-sectional studies of athletes had predicted, and almost identical to a longitudinal study of master runners from two decades ago. Aging did not spare these committed exercisers.

Most of the drop came from the heart. Maximum heart rate fell by 11 beats per minute, and the oxygen delivered per heartbeat shrank by about 15 percent. Muscle declined too. Lean tissue fell by 4.3 kg and fat rose by 3.3 kg, so the bathroom scale barely moved while body fat climbed from 24 to 29 percent. This hidden shift matters because cycling, the main exercise this group did, puts little load on muscle and bone.

Even so, decline is not the main finding. At follow-up, all but one of the 78 people who completed the exercise test sat at or above the 90th percentile for their age and sex in a large reference database. Blood pressure, glucose, triglycerides and HDL cholesterol barely changed. These riders lost fitness, but they started so high that they finished far above their peers.

The study also shows what they did not escape. Only 35 of the 82 returners remained free of disease. Twenty-three developed poorly controlled illness, 96 percent of it cardiovascular, including coronary disease and aortic dilation. Some of these conditions are more common in long-term endurance athletes. The study cannot say whether riding caused them, prevented something worse, or had no effect. Riders with compromised health lost more fitness, 24 percent against 17 percent in the disease-free group, but still ranked near the top of the population.

There are important caveats. A third of the original cohort did not return, including eight who had died, and those who stayed away had higher blood pressure at the start. The returners are therefore likely the healthiest survivors. There is no inactive comparison group, so the study cannot measure how much exercise slowed decline. It can only show what decline looks like in people who kept exercising. Training volume also fell by a third, which blurs the line between aging and detraining.

The conclusion is sobering rather than triumphant. Exercise does not stop the clock and does not guarantee an old age free of disease. What it does is raise the whole curve. The losses still come, but they start from a much higher point and leave people well above the threshold where daily life becomes difficult.

Actionable Insights

  1. Expect aerobic fitness to fall about 2% per year after 60, even if you train. In this study, staying active kept almost everyone in the top 10% for their age. In large population studies, each extra MET of fitness (one unit of exercise capacity) is linked to about 13% lower death risk. These riders lost 2.5 METs over nine years but still ended at about 10 METs, a level associated with low risk.
  2. Cycling alone did not protect muscle. Lean mass fell by 4.3 kg (8%) and body fat rose by 5.4 percentage points. The body-fat change is a large effect, roughly equal to the typical difference between two random participants at baseline. Add resistance training at least twice a week, and keep protein intake at about 1.0 to 1.5 g per kg per day. Protein intake fell slightly in this cohort.
  3. Don’t rely on the scale. Weight stayed flat while composition worsened. Track body composition with a DEXA scan or at least your waist measurement.
  4. If you are an older, high-volume endurance athlete, get your heart screened. Twenty-seven percent of returners developed poorly controlled disease, mostly cardiovascular. Reasonable checks include an ECG, a coronary calcium score and an aortic assessment. [Confidence: Medium]
  5. Protect your training volume. Riding dropped by a third, and this may explain part of the fitness loss.

Context and Source

  • Open Access Paper: A 9-year longitudinal investigation into physiological aging in highly active older adults, Published: 28 September 2026.
  • Institutions: Centre for Human and Applied Physiological Sciences, King’s College London; MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham
  • Country: United Kingdom
  • Journal: GeroScience (Springer; official journal of the American Aging Association).
  • Impact evaluation: Springer lists GeroScience’s 2025 Journal Impact Factor as 6.0. The impact score of this journal is 6.0, evaluated against a typical high-end range of 0 to 60+ for top general science, therefore this is a Medium impact journal. Within aging and gerontology it is a top-tier specialty outlet.

Related Reading:

Biomarker Data (Effect Size Extraction)

How to read this table: Cohen’s d measures how big a change is compared with how much people normally differ from each other. A d of about 0.2 is small, 0.5 is medium and 0.8 or higher is large. I estimated d as the average change divided by the spread between participants at baseline. The paper does not report standard deviations, so I back-calculated that spread from the reported 95% confidence intervals. Treat these as approximations. Changes are baseline to nine years across the whole cohort.

Measure Baseline +9 years Absolute change % change Approx. Cohen’s d Plain meaning
VO2peak (ml/kg/min) 44.1 35.4 -8.7 -19.7% 1.3 Very large decline
VO2peak per kg lean mass 57.8 49.9 -7.9 -13.7% 1.0 Large; about 30% of the loss is explained by losing muscle
VO2peak in METs 12.6 10.1 -2.5 -20% 1.2 Large, but still high for age
Max heart rate (bpm) 168 157 -11 -6.5% 0.8 Large; the main central limiter
Oxygen pulse (ml/beat) 18.1 15.4 -2.7 -15% 0.7 Medium to large; less oxygen delivered per beat
Ventilatory threshold (ml/kg/min) 33.7 28.7 -5.0 -14.8% 0.9 Large
VT as % of VO2peak 76.7 81.8 +5.0 points +6.6% 0.6 Submaximal capacity relatively preserved
VE/VCO2 slope 26.3 31.7 +5.4 +20.5% 1.3 Large loss of ventilatory efficiency
VO2 kinetics tau (s, median) 23.4 27.6 +3.5 +15% not calculable (skewed data) Slower response to a workload increase
Lean mass (kg) 53.0 48.7 -4.3 -8.1% 0.5 Medium vs between-person spread, but nearly universal within people
Fat mass (kg) 16.5 19.8 +3.3 +20% 0.8 Large
Body fat (%) 23.8 29.2 +5.4 points +22.7% 0.9 Large
FVC (L) 5.2 3.7 -1.6 -31% 1.2 Implausibly large (see Limitations)
FEV1 (L) 3.4 2.7 -0.7 -21% 0.8 Large, and above expected aging rates
LDL (mmol/L) 3.3 3.0 -0.37 (about -14 mg/dL) -11% 0.3 Small; medication effects likely
Total cholesterol (mmol/L) 5.8 5.4 -0.4 -7% 0.35 Small
Fasting insulin (pmol/L, median) 33 40 +10 +21% not calculable (skewed data) Statistically real, clinically trivial
Systolic BP (mmHg) 131 134 +3 +2% not significant No meaningful change
Resting HR (bpm) 56 59 +3 +5% 0.3 Small

Insulin in context: converting to standard units, HOMA-IR moves from about 1.2 to about 1.4. Both values sit in the insulin-sensitive range. [Confidence: Medium, since this is my calculation from group medians]

Between-group effects (health status):

  • CH vs OA, VO2peak: the CH group lost an extra 2.8 ml/kg/min (95% CI 0.1 to 5.4). In relative terms that is a 24.2% vs 17.3% decline, about 40% faster. The standardized effect is roughly d = 0.6, but the confidence interval runs from almost zero to large, so the true size is poorly pinned down. [Confidence: Low to Medium on magnitude]
  • Failing formal VO2max criteria: odds ratio 3.95 (95% CI 1.07 to 14.8) for CH vs OA and SA combined. The CI spans a 14-fold range, which reflects the tiny numbers involved.
  • SA vs OA, LDL: a further drop of 0.8 mmol/L in SA. This is plausibly statin initiation, which the medication data (Supplementary Fig. 2) would clarify. [Confidence: Low, speculative]
  • Sex differences: small and largely eliminated after normalizing to body or lean mass. The annual VO2peak decline was 2.2% for men and 2.1% for women.

Translating fitness into mortality: in meta-analytic data, each 1-MET increment is associated with about 13% lower all-cause mortality. Applied naively to their own trajectory, a 2.5 MET loss corresponds to roughly 35% higher relative risk than their 63-year-old selves. However, finishing at about 10 METs still places them in fitness strata associated with markedly lower risk than low-fitness peers. These are between-person epidemiological associations, not within-person causal estimates.

Novelty

  • This is one of few long-term longitudinal datasets on non-competitive but highly active older adults of both sexes, with repeat laboratory CPET, DEXA and O2 kinetics in the same lab at the same time of year. [Confidence: High]
  • The longitudinal VO2peak decline of about 2.2% per year is 1.7 to 3 times faster than cross-sectional estimates, including this cohort’s own baseline estimate of 1.26% per year. This is further evidence that cross-sectional designs underestimate true within-person aging in active populations. [Confidence: High]
  • The trajectories of men and women were nearly identical and close to those in master runners, suggesting the decline rate is largely independent of exercise mode. [Confidence: Medium]
  • Stratifying by incident health status shows that disease accelerates fitness loss only modestly (about 7 percentage points over nine years) in people who keep training. [Confidence: Medium, conditional on survivor bias]
  • Unexpected finding: 28% of a cohort screened as healthy developed poorly controlled, mostly cardiovascular disease within nine years despite sustained high activity. This is a signal worth quantifying against population incidence. The study could not do that. [Confidence: Medium for the signal, Low for interpretation]

Bottom line:

Sustained endurance training in later life appears to preserve high absolute fitness and a clean metabolic profile, but it does not prevent roughly 2% annual aerobic decline, sarcopenia, fat gain or cardiovascular disease.

This is great news, nearly 45% were still free of disease.

Goes without saying, and many cyclists know that.

On a more global note : Body fat at nearly 30% and still that fit (upper percentile ) is somewhat impressive. I’m guessing that this is the power of being active for decades.

@RapAdmin please break down some of these findings by the 3 health groups in the study . For example, we can see that successful agers’ fat mass gain and fat % was lowest among the 3 groups and the more fat mass gained and %, the worse.

It would be nice to know on which medication subjects were.

We’ve seen bunch of studies emphasizing intensity to keep vo2max, this one suggests it’s not one or the other, it’s both volume and intensity

Actigraphy showed small declines in the duration of light and moderate physical activity, sedentary time decreased, whilst the duration of hard and very hard activity and mean daily metabolic equivalents (METs) remained unchanged. There was a 33.5% fall in self-reported monthly cycling volume over 9 years, but it is acknowledged that this is a very blunt measure when capturing the fluctuations in overall training that may exist week to week. In the original cross-sectional study, no association was observed between age and self-reported training volume and no association with the change in cycling volume and age was observed here. The importance of maintaining training volume is supported by previous longitudinal studies of master athletes which have reported better preservation of V̇O2max among those who have maintained their training volume

Prompt:

break down some of these findings by the 3 health groups in the study . For example, we can see that successful agers’ fat mass gain and fat % was lowest among the 3 groups and the more fat mass gained and %, the worse.
It would be nice to know on which medication subjects were.

Claude Opus 5.5 Response:

You’re right that fat gain tracked with worse outcomes, but the group ordering is different from what you described. Successful agers (SA) did not have the lowest fat gain. Optimal agers (OA) gained the least fat mass. OA and SA tied on body fat percentage. The compromised-health group (CH) was worst on both. The overall pattern is a gradient from OA to SA to CH, not an SA advantage.

Breakdown by Health Group (Table 2)

Group sizes: OA n = 35 (23 men, 12 women), SA n = 24 (14, 10), CH n = 23 (16, 7). Only 19 CH participants completed exercise testing.

A caution before the numbers: the authors say the within-group changes in Table 2 are descriptive and were not tested. Only the flagged rows showed a statistically significant between-group difference in the mixed-effects model. Everything else is directional at best.

Body composition

Measure (9-year change) OA SA CH Significant group difference?
Fat mass +2.8 kg (+18%) +3.5 kg (+21%) +3.9 kg (+23%) None
Body fat % +5.1 points +5.1 points +6.1 points None
Lean mass -4.2 kg (-8.1%) -3.7 kg (-7.0%) -5.1 kg (-9.3%) SA vs CH
Total “recomposition” (lean lost + fat gained) 7.0 kg 7.2 kg 9.0 kg Not tested (my calculation)
Body weight -1.0 kg +0.1 kg -1.0 kg None

SA had the smallest lean-mass loss, and that is the only body-composition contrast that reached significance. CH had the worst recomposition on every measure. The spread in fat gain between groups is only about 1 kg, and the confidence intervals overlap heavily. OA ranged 1.9 to 3.7 kg and CH 2.6 to 5.3 kg. [Confidence: High that the gradient is directional, Low that it is real]

Cardiorespiratory function

Measure (9-year change) OA SA CH Significant group difference?
VO2peak (ml/kg/min) -7.8 (-17.3%) -8.6 (-19.5%) -10.5 (-24.2%) OA vs CH
VO2peak per kg lean mass -6.6 (-11.4%) -7.9 (-13.6%) -10.3 (-18.0%) OA vs CH
Power at VO2peak (W) -44 (-17.5%) -49 (-18.7%) -73 (-27.4%) OA vs CH, SA vs CH
Oxygen pulse (ml/beat) -2.4 (-13.6%) -2.3 (-12.5%) -3.9 (-21.2%) OA vs CH, SA vs CH
Max heart rate (bpm) -9 -14 -11 OA vs SA
VT per kg lean mass -2.2 (-5.0%) -4.3 (-9.5%) -5.6 (-12.8%) OA vs CH
VE/VCO2 slope 25.6 to 30.7 26.0 to 30.5 28.1 to 35.0 None
VO2 kinetics tau (s) +1.5 +4.7 +5.7 None (very wide CIs)
Resting heart rate (bpm) +1.9 +3.1 +4.9 None

The CH penalty is mostly central. Oxygen pulse fell about 60% more than in the other groups, and power at peak fell by 73 W against about 45 W. This fits cardiac disease plus beta blockers or pacemakers limiting maximal cardiac output.

The CH group’s VE/VCO2 slope was already the highest at baseline (28.1) and reached 35.0 at follow-up. In cardiology, slopes above about 34 carry prognostic weight, so this points to emerging cardiopulmonary pathology rather than aging alone. [Confidence: Medium]

Normalizing to lean mass does not close the gap for CH. They lost 18% per kg of lean tissue against 11% in OA. So their extra fitness loss is not just the product of losing more muscle or gaining more fat. It is a loss of function per unit of tissue. [Confidence: Medium]

Metabolic and blood pressure

Measure (9-year change) OA SA CH Significant group difference?
LDL (mmol/L) 0.0 -0.9 (-26%) -0.4 OA vs SA
Total cholesterol (mmol/L) -0.1 -0.8 -0.5 OA vs SA
Fasting insulin (pmol/L, median) +8 +11.5 +11.5 None
Systolic BP (mmHg) 127 to 129 135 to 141 134 to 136 None
Glucose, HDL, triglycerides Flat Flat Flat None

The insulin rise follows the same OA-lowest pattern as fat gain, which fits your hypothesis directionally. The differences are small and were not significant.

Wellbeing and activity

  • SF-12 physical health score: CH fell 3.6 points against less than 1 point in OA and SA. This was significant against both groups, so the CH participants noticed their decline.
  • Anxiety: fell in OA (-1.0) but was flat in CH.
  • Training: cycling volume fell by a similar amount in all three groups (roughly 200 to 250 km/month). The CH group’s “very hard” activity fell by 20 min/day while OA’s rose by 9. This contrast was not flagged as significant.

Baseline predictors (who ended up where)

  • CH membership was predicted by higher baseline systolic BP, higher lean mass and slightly less light activity.
  • SA membership was predicted by higher baseline systolic BP, higher sodium intake and lower FEV1 % predicted.
  • Non-return was predicted by higher systolic BP. Non-returners averaged 138.8 mmHg against 126.6 in OA.

Blood pressure at age about 63, even within the “healthy” range, was the most consistent early signal of who would develop disease or drop out. For a biohacker audience, this is arguably the most actionable group-level finding in the paper. [Confidence: Medium, given small n and exploratory models]

On your fat hypothesis

Across the three groups, more fat gain lines up with worse cardiorespiratory decline, higher insulin and more disease. But this is a comparison of group averages across only three groups defined by disease status, not by fat gain. It cannot show that fat gain drove the worse outcomes. Emerging cardiovascular disease, medications and reduced training could each drive both fat gain and fitness loss.

Testing your hypothesis properly would need an individual-level regression of fat mass change against VO2peak change, which the authors did not report. The dataset is available on request from the corresponding author. [Confidence: Medium on direction, Low on causality]

I added the supplementary information when Claude could not get them

The supplementary figures change several of my earlier inferences. One is confirmed, one is refuted, and a new finding stands out: most of the compromised-health (CH) group were not being treated for their cardiovascular disease.

A reminder on the fat question: successful agers (SA) did not gain the least fat. Optimal agers (OA) gained the least fat mass (+2.8 kg, against +3.5 kg in SA and +3.9 kg in CH). OA and SA tied on body fat percentage (+5.1 points each), and CH was worst (+6.1). None of these differences were statistically significant.

1. Who Was in Each Group (Supplementary Fig. 1)

OA (n=35) SA (n=24) CH (n=23)
Participants with zero diagnosed conditions 31 (89%) 0 0
Participants with 3 or more conditions 0 1 (4%) 9 (39%)
Any cardiovascular condition 0% 38% 96%
Cancer 0% 17% 13%
Respiratory 0% 17% 13%
Endocrine or metabolic 3% 21% 13%
Musculoskeletal 0% 21% 4%

Cardiovascular conditions, approximate counts read from the bars:

  • SA: hypertension in about 8 people and benign ectopic beats in 1. Hypertension is essentially the whole cardiovascular story in this group.
  • CH: hypertension about 8, atrial fibrillation about 6, coronary artery disease about 4. Two people each had aortic valve stenosis, prior myocardial infarction, atrial flutter or other valvular disease. There was one case each of complete AV block, left bundle branch block, heart failure with reduced ejection fraction, sinus bradycardia, myocardial ischaemia, pulmonary embolism, cardiomyopathy, ruptured abdominal aortic aneurysm and supraventricular tachycardia.

Rhythm and conduction problems dominate the CH group. Atrial arrhythmias (AF, flutter and SVT) affect roughly 8 to 11 of the 82 returners, depending on overlap between diagnoses. This matches the pattern described in veteran endurance athletes, where atrial fibrillation, conduction disease and coronary plaque are over-represented.

Without an age-matched population comparison, however, the study cannot say whether this rate is actually elevated. AF prevalence in people in their 70s is already in the mid-to-high single digits. [Confidence: Medium that the pattern fits athlete’s-heart pathology, Low that the rate is elevated]

Cancer appears in 7 returners (4 SA, 3 CH), in addition to the 4 cancer deaths among non-returners.

2. Medications by Group (Supplementary Fig. 2)

By drug class (% of group)

Class OA SA CH
Antithrombotics 0% 4% 26%
Antihypertensives 0% 17% 22%
Beta-blocker or rate control 0% 0% 13%
Lipid-lowering 3% 25% 9%
Thyroid 0% 17% 9%
Acid suppression (PPI) 9% 0% 9%
Respiratory inhalers 0% 8% 9%
Urological (BPH) 0% 4% 9%
Antidepressant or anxiolytic 0% 4% 4%
Bone health 0% 8% 0%
Heart-failure therapy 0% 0% 4%
Systemic corticosteroid 0% 0% 4%

Specific cardiovascular drugs (approximate counts)

  • OA: statin (1).
  • SA: statin (6), amlodipine (3), alirocumab (1), losartan (1), perindopril (1), aspirin (1).
  • CH: ramipril (4), bisoprolol (3), aspirin (2), rivaroxaban (2), statin (2), amlodipine (1), apixaban (1), edoxaban (1), lercanidipine (1), sacubitril/valsartan (1).

Medication burden

OA SA CH
Taking no medications 31 (89%) 8 (33%) 10 (43%)
Taking 4 or more medications 0 0 3
Taking no cardiovascular drugs 34 (97%) 15 (63%) 13 (57%)

3. What the Medications Explain (and What They Don’t)

SA’s cholesterol drop: confirmed as drug-driven

A quarter of SA were on lipid-lowering therapy: six on a statin, one of whom was also on alirocumab (a PCSK9 inhibitor that lowers LDL by roughly half). This easily accounts for SA’s 0.9 mmol/L LDL drop, against no change in OA.

This matters for interpretation. The paper’s finding that SA had a “larger reduction in total and LDL cholesterol” is a treatment effect, not an effect of aging or exercise. [Confidence: High]

SA’s larger max heart rate drop: not explained by beta blockers

No SA participant took a beta blocker or rate-control drug. Their decline of 14 bpm in max heart rate (against 9 in OA) came from something else. Candidates include true biological variation, a chance finding in an exploratory test, or effort differences on test day. The confidence interval (-9.6 to -0.5 bpm) sits close to zero. [Confidence: Low for any explanation]

CH’s larger VO2peak decline: only partly explained by drugs

Only 3 of 23 CH participants took bisoprolol. At most one or two had pacemakers, inferred from the AV block and bradycardia diagnoses. The authors cite beta blockers and pacemakers as a reason for CH’s steeper decline, but this applies to only a small minority of the group.

Most of CH’s extra loss in oxygen pulse and peak power is better attributed to the disease itself: AF, valve disease, coronary disease and one case of heart failure with reduced ejection fraction. [Confidence: Medium]

Most of the CH group was untreated

This is the finding that stands out. Ninety-six percent of CH had cardiovascular disease, yet 57% took no cardiovascular medication and 43% took no medication at all. Roughly 6 CH participants had AF, but only 4 were on an anticoagulant (rivaroxaban, apixaban or edoxaban).

“Poorly controlled” therefore appears to mean mostly untreated or undiagnosed, not failing on therapy. Some diagnoses were probably made by the study’s own clinician-reviewed ECG and blood pressure screening. If so, the study effectively found a sizeable burden of unrecognized heart disease in fit older cyclists.

The practical message for fit older adults: high fitness can mask significant cardiac disease, so screening should not be skipped because someone is fit. [Confidence: Medium, since the timing of diagnosis is not reported]

SA’s hypertension was not really “well controlled”

About 8 SA participants had hypertension, but only 4 took antihypertensives. SA’s mean systolic pressure at follow-up was 141 mmHg, above the usual 140 threshold. This is a definitional weakness in the grouping. [Confidence: Medium]

OA was not entirely medication or disease free

Four OA participants took medication: one a statin and three a PPI. The figure notes that the authors inferred conditions for these participants from their medications. These people were still classed as meeting the original health criteria. This is a minor inconsistency, but it slightly blurs the line between the “disease-free” and “successful” groups.

A statin caveat for a mitochondria audience

In a randomized trial of previously sedentary adults, simvastatin blunted the improvement in VO2max from exercise training and reduced muscle mitochondrial content. SA, with 25% on statins, had an intermediate VO2peak decline (-19.5%, between OA and CH).

Six statin users are far too few to test this, and the context differs: these were maintenance-trained athletes, not people starting training. Still, it is a question worth raising for statin-using endurance athletes who track VO2max. [Confidence: Low for relevance here]

4. Training and Age Did Not Predict Decline (Supplementary Fig. 5)

Correlation with % change in VO2peak Spearman rho P n
Baseline age -0.117 0.31 78
% change in cycling volume 0.108 0.35 76
% change in sedentary time 0.097 0.41 74
% change in light activity 0.134 0.26 74
% change in moderate activity -0.039 0.74 74
% change in hard activity -0.018 0.88 74
% change in very hard activity 0.041 0.73 74

In plain terms, none of these factors explains more than about 2% of the differences between people in how much fitness they lost. That is effectively nothing.

“Not significant” is not the same as “no effect,” though. For the cycling-volume correlation, the 95% confidence interval runs from about -0.12 to +0.34 (my calculation). A true correlation of 0.3, meaning training explains about 10% of the variation, cannot be ruled out with 76 people and a self-reported measure. The authors’ statement that training change was unrelated to VO2 decline should be read as “no detectable relationship.” [Confidence: High]

By eye, the scatterplots show two more things:

  • The worst decliners (losses beyond about 32%) are disproportionately red, meaning CH. Health status appears to matter more than age or training change.
  • Several people increased their cycling volume, one by roughly 300%, and still lost 18% of their VO2peak. Adding more volume did not protect against decline.

5. Your Fat Hypothesis Revisited

The supplementary data do not support fat gain as the driver of group differences.

  • Disease burden and cardiac pathology (AF, valve and coronary disease) are much stronger candidates. These are the variables that most sharply separate CH from the other groups.
  • Drugs that commonly cause weight gain were rare. Only 3 people took a beta blocker, a class associated with modest weight gain, and systemic corticosteroid use was a single case.
  • Thyroid replacement was most common in SA (17%). Treated hypothyroidism could plausibly influence body composition, but SA’s fat gain was intermediate, so there is no clear signal.

Group-level fat gain does run in the same direction as worse outcomes (OA lowest, CH highest). But with a spread of about 1 kg, heavily overlapping confidence intervals, and a group structure defined by disease, the data cannot separate fat gain from the diseases that cause both. An individual-level analysis within groups would be needed, and it isn’t reported. [Confidence: Low for fat as an independent driver]

Revised Bottom Line by Group

  • OA (35): Nearly all medication free and disease free. This is the cleanest “exercise plus aging” signal: a 17% VO2peak decline, 4.2 kg lean loss and 2.8 kg fat gain over nine years.
  • SA (24): Mainly mild, partly treated hypertension, plus thyroid, respiratory, musculoskeletal and cancer diagnoses. They look physiologically much like OA. Their “better cholesterol” is a statin and PCSK9 effect.
  • CH (23): Mainly arrhythmia, conduction, valve and coronary disease, and mostly untreated. They had the largest fitness and lean mass losses and the largest fat gain. Even so, all but one stayed at or above the 90th percentile for fitness, which shows how much a high fitness level can hide.

References

  1. Fathi AS, Francis T, Milbourn E, et al. A 9-year longitudinal investigation into physiological aging in highly active older adults. GeroScience. 2026. A 9-year longitudinal investigation into physiological aging in highly active older adults | GeroScience | Springer Nature Link (Table 2; Supplementary Figs. 1, 2 and 5)
  2. Mikus CR, Boyle LJ, Borengasser SJ, et al. Simvastatin, with or without exercise, attenuates improvements in cardiorespiratory fitness in overweight or obese adults. J Am Coll Cardiol. 2013;62(8):709-714.
  3. Sharma AM, Pischon T, Hardt S, Kunz I, Luft FC. Hypothesis: beta-adrenergic receptor blockers and weight gain: a systematic analysis. Hypertension. 2001;37(2):250-254.
  4. Robinson JG, Farnier M, Krempf M, et al. Efficacy and safety of alirocumab in reducing lipids and cardiovascular events (ODYSSEY LONG TERM). N Engl J Med. 2015;372(16):1489-1499.
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