{% set zones = fitness_zones(current_user) %}
<section class="panel settings-card"><span class="eyebrow">RUNNING FITNESS</span><h2>Heart-rate zones</h2>
<p>{{ zones.source }}{% if zones.max_hr %} · {{ zones.max_hr }} bpm{% endif %}</p>
<p>{% for label in zones.labels %}Z{{ loop.index }}: {{ label }} bpm{{ ' · ' if not loop.last }}{% endfor %}</p>
<form method="post" action="{{ url_for('training.zones') }}" class="stack"><input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
<label>Zone calculation<select name="mode"><option value="auto" {{ 'selected' if zones.mode == 'auto' }}>Automatic from age</option><option value="max" {{ 'selected' if zones.mode == 'max' }}>Manual maximum heart rate</option><option value="custom" {{ 'selected' if zones.mode == 'custom' }}>Manual zone boundaries</option></select></label>
<label>Birthday (optional, for automatic updates)<input type="date" name="birthday" value="{{ zones.config.get('birthday', '') }}"></label>
<label>Maximum HR (for manual maximum mode)<input type="number" name="max_hr" min="100" max="230" value="{{ zones.config.get('max_hr', '') }}"></label>
{% for boundary in zones.boundaries %}<label>Z{{ loop.index + 1 }} starts at (bpm, for manual zones)<input type="number" name="z{{ loop.index + 1 }}" min="30" max="230" value="{{ boundary }}" required></label>{% endfor %}
<p class="field-help">Automatic mode uses 220 minus age, or 190 bpm without a birthday. Zones begin at 65%, 80%, 87% and 95% of maximum HR (rounded to the nearest bpm). These are Stride's published defaults, which may differ from Strava. Age-based zones update on your birthday. Manual settings remain fixed until edited.</p>
<p class="field-help">New runs and rest days update the fitness graph automatically. Zone edits recalculate all historical scores using the current zones. Existing three-band Stats settings are independent.</p>
<button class="button primary">Save fitness zones</button></form></section>