Double support time: The balance metric that reveals how you are aging

Every step you take tells a story about your body’s age — and one of the most revealing chapters is written in the fraction of a second when both feet touch the ground simultaneously.

That brief moment, called double support time, is one of the most sensitive gait parameters to aging. Research from the Baltimore Longitudinal Study of Aging shows that double support time increases by roughly 1% per decade after age 60 — a seemingly small shift that carries outsized consequences for fall risk, independence, and longevity.

The problem? Most people have never heard of it. While step counts and walking speed dominate health conversations, double support time quietly reflects something deeper: how much your body trusts its own balance.

What you’ll learn:

• What double support time measures and why it increases with age
• How to use age context without overfocusing on one reading
• How this single metric connects to fall risk, cognitive function, and biological age
• 6 evidence-based strategies to reduce your double support percentage

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Quick answer

Double support time is the share of your walking cycle spent with both feet on the ground. A higher percentage usually means your body is choosing a more cautious, stable gait pattern.

Rising double support can reflect aging, slower walking speed, pain, vestibular issues, poor strength, uneven terrain or simply carrying your phone differently. Treat it as a trend metric, not a diagnosis.

The most useful pattern is direction over time: stable or decreasing values during normal walks are reassuring, while a sudden rise, high variability or worsening walking speed deserves attention.

Key facts

• Double support -> balance margin: more time on two feet usually means the nervous system wants extra stability.
• Apple Health -> passive metric: iPhone estimates Walking Double Support Percentage during eligible walks when the phone is carried properly.
• Trend -> context: compare similar walks on flat ground, not isolated readings from hills, crowds or carrying loads.
• Speed -> interpretation: double support often rises when gait speed falls, so read both metrics together.
• Variability -> fall risk: inconsistent double support from step to step can be more concerning than the average alone.
• Training -> modifiable: strength, balance, brisk walking and dual-task practice can improve gait confidence over weeks.

What is double support time?

Double support time is the percentage of your gait cycle spent with both feet on the ground simultaneously. During normal walking, your body alternates between two phases: single support (one foot in the air, one on the ground) and double support (both feet touching the ground at the same time).

Quick definition: Double support time is the percentage of your walking cycle when both feet are in contact with the ground — a direct measure of balance confidence during gait.

Every gait cycle includes two double support phases: one at the beginning of each step (initial contact) and one at the end (terminal contact). Together, these phases typically account for about 20% of the total gait cycle in healthy adults walking at a comfortable pace.

Why double support time matters for your health

Think of double support time as your body’s built-in safety margin. When your neuromuscular system feels confident, it allows longer periods of single-leg support — the dynamic, efficient phase of walking. When balance is compromised, your body instinctively increases double support time to maintain a wider, more stable base.

This isn’t a conscious decision. Your central pattern generators — neural circuits in the spinal cord that coordinate walking — automatically adjust gait parameters based on real-time sensory feedback from your proprioceptive, vestibular, and visual systems. Increased double support time is the nervous system’s way of saying: “I need more stability.”

That’s why this metric is so clinically valuable. Unlike walking speed, which you can consciously control, double support time reveals the unconscious assessment your body makes about its own stability with every single step.

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The science behind double support time

How double support time changes with age

The gait cycle is exquisitely sensitive to aging. A landmark study published in the Archives of Physical Medicine and Rehabilitation found that among healthy adults:

Age Group	Double Support Time (% of gait cycle)	Gait Speed
20–40	18–20%	4.0–4.5 ft/s (1.2–1.4 m/s)
40–60	20–23%	3.6–4.3 ft/s (1.1–1.3 m/s)
60–75	23–27%	3.0–3.9 ft/s (0.9–1.2 m/s)
75+	27–32%	2.3–3.3 ft/s (0.7–1.0 m/s)

Several physiological mechanisms drive this increase:

1. Muscle power decline. Ankle plantarflexors (particularly the soleus and gastrocnemius) generate the push-off force that propels you into single-leg stance. After age 50, these muscles lose approximately 1.5–2% of their power per year, forcing longer double support phases to compensate.

2. Proprioceptive degradation. Mechanoreceptors in your feet, ankles, and knees provide the sensory data your brain uses to maintain balance. These receptors decline in density and sensitivity with age, reducing the quality of balance information available during single-leg phases.

3. Vestibular changes. The vestibular system loses approximately 3% of its hair cells per decade after age 40. With less accurate information about head position and acceleration, the brain compensates by keeping both feet on the ground longer.

4. Neural processing speed. The time required to process balance-related sensory information and generate corrective motor responses increases with age. Longer double support provides a larger temporal window for these slower neural computations.

Double support time and walking speed

Double support time and walking speed share an inverse relationship — as one increases, the other decreases. Research from the Baltimore Longitudinal Study of Aging demonstrated that gait speed decline is closely associated with increased double support time and decreased stride length.

At very slow walking speeds (below 2.0 ft/s or 0.6 m/s), double support can exceed 35% of the gait cycle. Conversely, during fast walking or running, double support approaches zero — and eventually disappears entirely (running is defined by having a “flight phase” with no ground contact).

This relationship matters because walking speed itself is a powerful predictor of mortality. A 2011 meta-analysis in the Journal of the American Medical Association found that every 0.1 m/s increase in gait speed was associated with a 12% reduction in mortality risk. Double support time is one of the primary mechanisms through which this speed-mortality connection operates.

Double support time and longevity: what the research says

The connection between double support time and biological aging extends beyond simple balance. Research reveals multiple pathways:

Cognitive function. A 2014 study of adults aged 50–80 found that participants who failed cognitive tasks while walking showed significantly longer double support time. This “dual-task cost” — the increase in double support when you walk and think simultaneously — may be an early marker of cognitive decline, appearing years before clinical symptoms.

Fall risk. While average double support time predicts fall risk, the variability of double support time is an even stronger predictor. A study of elderly women with vestibular asymmetry found that increased double support variability — inconsistency from step to step — was significantly associated with fall history. Your body’s inability to maintain a consistent rhythm signals deteriorating neural control.

Cardiovascular health. Poor cardiovascular fitness reduces oxygen delivery to working muscles during walking, forcing compensatory gait changes including increased double support. Regular aerobic exercise can reverse this pattern, reducing double support time independent of other interventions.

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How to use double support time norms

This article focuses on why double support time changes and how to improve it. If you mainly want the age-specific benchmark table, use the companion reference guide: double support time by age chart and normal ranges.

For quick context, here are broad evidence-based ranges:

For women

Age	Optimal	Normal	Elevated	Concerning
20–39	< 18%	18–21%	21–25%	> 25%
40–59	< 20%	20–24%	24–28%	> 28%
60–74	< 23%	23–27%	27–30%	> 30%
75+	< 26%	26–30%	30–34%	> 34%

For men

Age	Optimal	Normal	Elevated	Concerning
20–39	< 17%	17–20%	20–24%	> 24%
40–59	< 19%	19–23%	23–27%	> 27%
60–74	< 22%	22–26%	26–29%	> 29%
75+	< 25%	25–29%	29–33%	> 33%

Important notes:

• These values assume comfortable, self-selected walking speed on flat ground
• Walking on uneven surfaces, slopes, or while carrying objects naturally increases double support
• Absolute duration is typically 0.30–0.32 seconds per double support phase in older adults
• Your iPhone measures this metric as “Walking Double Support Percentage” in Apple Health

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6 proven ways to reduce double support time

Reducing double support time requires targeting the underlying causes — muscle weakness, balance deficits, and neuromuscular coordination. Here are evidence-based strategies:

1. Strengthen your ankle complex

Why it works: The push-off phase of gait — powered primarily by the ankle plantarflexors — is what launches you into single-leg stance. Stronger ankles mean more confident, powerful push-offs and less time needing both feet on the ground.

How to do it:

• Calf raises: 3 sets of 15 reps, progressing to single-leg
• Eccentric heel drops off a step: 3 sets of 12 reps
• Ankle dorsiflexion stretches: 30 seconds, 3 times per leg
• Resistance band ankle inversions and eversions: 2 sets of 15

Expected results: 4–8 weeks of consistent ankle strengthening can improve push-off power by 15–20%, directly translating to reduced double support.

2. Practice single-leg balance progressions

Why it works: Single-leg balance training directly challenges the systems that double support compensates for — proprioception, vestibular processing, and hip/ankle stabilization. The better you balance on one leg, the less you need both feet for safety.

How to do it:

• Start with 30-second single-leg stands, eyes open
• Progress to eyes closed (removes visual compensation)
• Add an unstable surface (foam pad, BOSU ball)
• Advance to single-leg reaches in multiple directions

Expected results: A 2023 study found that the single-leg balance test correlated strongly with gait quality. Improving from 10 seconds to 30 seconds of single-leg balance typically reduces double support by 2–4%.

3. Walk faster — deliberately

Why it works: Walking speed and double support time are inversely linked. By deliberately increasing your walking pace during structured walks, you force your neuromuscular system to reduce double support. Over time, this faster pattern becomes your new default.

How to do it:

• Start with 10-minute brisk walking intervals at 80–85% of maximum pace
• Use a metronome app set to 120–130 steps per minute
• Gradually increase interval duration to 20–30 minutes
• Monitor your walking speed trend in Apple Health

Expected results: A 12-week progressive walking program can improve comfortable gait speed by 0.1–0.2 m/s and reduce double support by 1.5–3%.

4. Improve hip abductor strength

Why it works: Your hip abductors (gluteus medius and minimus) are the primary stabilizers during single-leg stance. Weakness causes the classic Trendelenburg pattern — pelvis dropping on the unsupported side — which the body compensates for by extending double support to avoid instability.

How to do it:

• Side-lying hip abductions: 3 sets of 15
• Banded lateral walks (monster walks): 3 sets of 20 steps each direction
• Single-leg Romanian deadlifts: 3 sets of 10 per leg
• Copenhagen plank holds: 3 sets of 20 seconds

Expected results: 6–8 weeks of targeted hip strengthening reduces lateral trunk sway and double support time, particularly on uneven surfaces.

5. Add dual-task walking training

Why it works: Cognitive decline increases double support time primarily through the dual-task mechanism — when the brain must divide attention between walking and thinking, gait quality suffers first. Practicing dual-task walking trains your brain to maintain efficient gait even under cognitive load.

How to do it:

• Walk while counting backwards from 100 by 7s
• Walk while naming items in a category (animals, countries)
• Walk while carrying on a conversation (the real-world dual task)
• Walk while performing a manual task (carrying a tray with a glass of water)

Expected results: Research shows dual-task training reduces the “dual-task cost” on double support time by 30–50% over 8 weeks, meaning your gait remains more efficient even when your brain is busy.

6. Practice tai chi or yoga

Why it works: Both disciplines combine balance challenge, proprioceptive training, weight shifting, and mindful movement — precisely the combination needed to improve the sensorimotor systems that govern double support time. Tai chi, in particular, involves continuous weight transfers from double to single support, directly training the transition your body struggles with.

How to do it:

• 2–3 sessions per week, 30–60 minutes each
• Focus on forms that emphasize weight shifting and single-leg postures
• Tai chi: 24-form Yang style is well-studied for fall prevention
• Yoga: warrior III, tree pose, and half-moon directly challenge single-leg balance

Expected results: A meta-analysis of 18 randomized controlled trials found tai chi reduced fall risk by 20% and improved gait parameters including double support time over 12 weeks. For a complete evidence-based balance training program that targets double support time through all these mechanisms, see our guide to balance training after 50.

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How to track and measure double support time

Your iPhone as a gait lab

Since iOS 14, your iPhone automatically measures walking double support percentage using its built-in accelerometer and gyroscope. The data appears in Apple Health under Mobility > Walking Double Support Percentage.

To get accurate readings:

• Carry your iPhone in a front pants pocket or hip belt
• Walk on flat ground at your normal comfortable pace
• The phone needs at least 20 consecutive steps to calculate a reliable value
• Measurements are aggregated as daily averages

Key metrics to monitor

Metric	What It Shows	Target
Double support %	Balance during walking	Below 25% (under 60)
Week-to-week trend	Direction of change	Stable or decreasing
Dual-task difference	Cognitive gait cost	Less than 5% increase
Walking asymmetry	Left-right difference	Below 10%
Walking speed	Overall gait quality	Above 3.0 mph (4.8 km/h)
Walking steadiness	Fall risk score	OK (above 70%)

When to be concerned

Talk to a healthcare provider if you notice:

• Double support consistently above 30% (under age 70)
• Rapid increase (>3% jump) over 2–4 weeks without explanation
• Large day-to-day variability (fluctuating by >5%)
• Double support increasing while other gait metrics remain stable (may indicate a balance-specific issue)

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How double support time connects to biological age

Double support time is more than a balance metric — it’s a window into your body’s functional age. Here’s why researchers increasingly view it as a biomarker of aging:

It integrates multiple systems. Unlike isolated tests (grip strength, VO2 max), double support time reflects the simultaneous function of your muscular, skeletal, neurological, vestibular, and cardiovascular systems. When any of these systems declines, double support increases — making it an exceptionally sensitive composite marker.

It predicts independence. Research consistently shows that elevated double support time predicts difficulty with activities of daily living — climbing stairs, crossing streets before traffic lights change, and carrying groceries while walking. Maintaining youthful double support percentages is directly tied to maintaining an independent lifestyle.

It responds to intervention. Perhaps most importantly for biological age tracking, double support time is modifiable. Unlike chronological markers, you can measurably improve this metric through targeted training — and studies show that improvements in double support time correlate with improvements in other aging biomarkers.

Want to go deeper? Learn how biological age is calculated and how gait metrics like double support time contribute to functional aging scores. For precise age-group benchmarks and a complete reference chart, see our companion guide: double support time normal ranges by age.

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How SuperAge helps you track double support time

Monitoring double support time in raw numbers is useful — but understanding what those numbers mean for your biological age is where real insight begins. SuperAge bridges that gap.

Automatic gait monitoring

SuperAge reads your walking double support percentage directly from Apple Health, combining it with other mobility metrics your iPhone already tracks — walking speed, step length, walking asymmetry, and walking steadiness. No extra devices needed.

Personalized context

Rather than comparing you to population averages, SuperAge evaluates your double support time against your age, sex, and activity level to determine whether your gait patterns reflect a younger or older biological profile.

Biological age integration

Double support time feeds into SuperAge’s comprehensive biological age calculation alongside cardiovascular, metabolic, and activity metrics. A reduction in double support can directly contribute to a lower biological age score — giving you tangible feedback on your training efforts.

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Frequently asked questions

What is a normal double support time for my age?

For adults under 60, a double support percentage below about 23% during comfortable walking is often normal. Between 60 and 75, values up to roughly 27% are common. Above 75, values up to about 30% can still fall within the expected range. For decade-by-decade thresholds and Apple Health interpretation, use the double support time by age chart.

Can I measure double support time without special equipment?

Yes. If you have an iPhone running iOS 14 or later, your phone automatically measures walking double support percentage whenever you walk with it in your pocket. Check Apple Health > Browse > Mobility > Walking Double Support Percentage. For clinical-grade measurements, gait laboratories use instrumented walkways or motion capture systems.

How quickly can I improve my double support time?

Most people see measurable improvement within 4–8 weeks of targeted training (ankle strengthening, balance exercises, and brisk walking). A realistic initial goal is a 2–3% reduction in double support percentage. Larger improvements of 4–6% are possible over 3–6 months with consistent multifactorial training.

Is high double support time the same as slow walking?

Not exactly. While they’re correlated, they can diverge. Someone might maintain a reasonable walking speed through increased step frequency while still having elevated double support — essentially taking more, shorter steps with more time spent in the double-foot phase. This compensatory pattern is common in early-stage balance decline and is worth monitoring even when walking speed appears normal.

Does double support time predict falls?

The variability of double support time is a stronger fall predictor than the average value alone. If your double support percentage fluctuates significantly from step to step or day to day, it suggests your neuromuscular system is struggling to maintain consistent gait control — a known precursor to falls.

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Key takeaways

• Double support time is the percentage of your gait cycle with both feet on the ground — it increases by ~1% per decade after age 60
• Normal values range from 18–20% in young adults to 27–30% in those over 75
• It reflects balance confidence at an unconscious level, integrating muscular, neural, and vestibular function
• Variability matters — inconsistent double support from step to step is a stronger fall predictor than the average value
• It’s modifiable — targeted ankle strengthening, balance training, and brisk walking can reduce double support by 2–6% in 8–12 weeks
• Your iPhone tracks it automatically as Walking Double Support Percentage in Apple Health

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Start improving your gait today

Your double support time is one of the most honest metrics your body produces — it reveals exactly how much your neuromuscular system trusts its own balance. The good news? It responds to training at any age.

Ready to take control? Download SuperAge and start tracking double support time alongside your biological age.

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References

1. Apple Developer Documentation. Walking Double Support Percentage. HealthKit.
2. Apple. Measuring Walking Quality Through iPhone Mobility Metrics. Apple Healthcare.
3. Brach, J.S. et al. (2015). Gait characteristics associated with walking speed decline in older adults: results from the Baltimore Longitudinal Study of Aging. Archives of Physical Medicine and Rehabilitation.
4. Studenski, S. et al. (2011). Gait speed and survival in older adults. JAMA.
5. Tian, Q. et al. (2017). Differential associations between dual-task walking abilities and usual gait patterns in healthy older adults. Experimental Gerontology.
6. Larsson, J. et al. (2015). Increased double support variability in elderly female fallers with vestibular asymmetry. Gait & Posture.
7. Sherrington, C. et al. (2019). Exercise for preventing falls in older people living in the community. Cochrane Database of Systematic Reviews.

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Last updated: 2026-06-07. This article is regularly reviewed for accuracy.