IP2X is built on published research — on exercise and longevity, strength training, the power of incentives, and what wearables can reliably measure. This is our working library of the studies and articles that inform the plan. Links open the original sources; where a study isn't freely linkable, we cite it so you can look it up.
147,000 people followed up to 30 years: resistance training alone is linked to lower mortality, and combined with aerobic exercise the reduction is greater still.
479,856 participants: aerobic activity cut all-cause mortality substantially, and combining it with resistance training cut it further.
~17,000 people: higher activity in early adulthood and midlife is associated with meaningfully lower all-cause mortality.
The incentives research behind Vitality-style programmes — loss-based rewards motivate sustained activity more than gain-based ones.
In patients at high cardiovascular risk, financial incentives increased physical activity over 12 months — with benefits that outlasted the intervention.
Walking did not increase spine bone density; other forms of skeletal loading are needed.
Competitive swimmers showed lower bone density than high-impact-sport athletes — closer to sedentary people.
Cycling was associated with lower bone mineral content, with a negative effect on peak bone mass.
Non-weight-bearing sports such as swimming and cycling are not effective for preventing osteoporosis.
Brisk walking produced a minimal bone-building response, with a greater risk of falls and fracture.
Resistance training is a proven, safe way to build muscle size and strength — effective even in frail individuals and after fracture.
Review of resistance training for building strength and supporting recovery in older and post-fracture populations.
A non-expert's guide to what consumer wearables can and can't reliably measure in cardiovascular care.
Validation of Fitbit and Garmin devices for measuring exercise capacity remotely.
Performance and limits of smartwatch estimates of cardiorespiratory fitness outside the lab.
Using smartwatch ECGs to help patients manage atrial fibrillation after ablation.
Long-term association between ultra-short HRV measures and cardiovascular risk.
Detecting premature atrial and ventricular contractions on wearable ECGs to predict cardiovascular events.
Validating HRV and oxygen-saturation readings derived from Garmin's Health Snapshot.
Assessing how accurately consumer-grade wearables track sleep in healthy people.
In middle-aged people without prior cardiovascular disease, wearable-derived long-term HRV predicts major cardiovascular events.
Wearable monitoring detects multi-system impairments in long-COVID cases reporting fatigue years after infection.
Identifying resistance-training exercises from wrist-motion sensors is feasible — but not yet proven on consumer wearables.
Pooled analysis of ~660,000 people showing the diminishing returns of exercise on mortality. (Referenced by Stephen without a direct link.)
Sensor study of 25,000 UK adults: a few minutes a day of vigorous incidental activity was linked to markedly lower mortality. (Referenced without a direct link.)
On the benefits of short, frequent bursts of activity. (Referenced without a direct link.)
Pooled 69 randomised trials of exercise for depression. (Referenced via The Economist without a direct link.)
Drew on 1,000+ trials and ~80,000 participants, finding exercise reduces depression and anxiety about as much as conventional treatments. (Referenced without a direct link.)
Popular write-up of the research on combining aerobic and weight training for longevity.
First-person feature on rebuilding bone density through progressive strength training.
Companion interview to the King's College London wearable-ECG research.
On "exercise snacks" and the mortality benefits of even tiny bursts of activity. (Subscriber article; no direct link supplied.)
Weighs the evidence comparing exercise with antidepressants and therapy. (Subscriber article; no direct link supplied.)
On protecting muscle and bone while losing weight on GLP-1s. (Shared as a clipping; no online link supplied.)