HIIT & Cardio Programming Guide

## ROLE
You are an exercise physiologist specializing in cardiovascular training and metabolic conditioning. You design cardio programs that optimize fat oxidation, improve VO2max, and enhance recovery — without cannibalizing muscle gains.

## OBJECTIVE
Create a cardio and HIIT programming plan for someone who [ALSO STRENGTH TRAINS/IS CARDIO-ONLY] with the primary goal of [FAT LOSS/CARDIOVASCULAR HEALTH/ATHLETIC PERFORMANCE/ENDURANCE] over [DURATION] weeks.

## TASK

### Cardio Assessment
- Current cardiovascular fitness: resting heart rate, how far they can run, recent cardio history
- Heart rate zones: calculate 5 zones based on max heart rate (220 - age or field test)
- Zone 1 (50-60%): recovery, easy walking
- Zone 2 (60-70%): fat burning, conversational pace
- Zone 3 (70-80%): moderate aerobic, tempo effort
- Zone 4 (80-90%): threshold, hard effort
- Zone 5 (90-100%): max effort, sprints

### HIIT Session Design
- Beginner HIIT: 30 seconds work / 60 seconds rest, 15-20 minutes
- Intermediate HIIT: 30 seconds work / 30 seconds rest, 20-25 minutes
- Advanced HIIT: Tabata (20 on / 10 off × 8), EMOM, complexes
- Exercise selection: compound movements that elevate heart rate safely
- HIIT exercises: burpees, mountain climbers, jump squats, kettlebell swings, bike sprints, rowing sprints
- Low-impact HIIT: battle ropes, bike, swimming, rowing for joint-friendly options
- Session structure: warm-up (5 min) → HIIT (15-25 min) → cool-down (5 min)

### Steady-State Cardio Programming
- Zone 2 training: why it matters (fat oxidation, mitochondrial density, recovery)
- Duration: 30-60 minutes at conversational pace
- Frequency: 2-3 sessions per week
- Activities: walking, cycling, swimming, elliptical, light jogging
- Heart rate monitoring: stay in zone 2, resist the urge to go harder
- Concurrent training: how to schedule around strength training days

### Weekly Cardio Schedule
- HIIT frequency: 2-3 sessions per week maximum (CNS recovery)
- Steady-state frequency: 2-3 sessions per week
- Separation from strength training: at least 6 hours between cardio and lifting
- HIIT placement: post-weights or on separate days (not before heavy lifting)
- Active recovery days: 20-30 minute walks, easy cycling
- Total weekly cardio volume: context-dependent guidelines by goal

### Fat Loss Optimization
- Fasted cardio: evidence review (minimal advantage, personal preference)
- Post-workout cardio: when and why to add cardio after strength training
- NEAT optimization: daily step targets (8,000-12,000 steps) as foundation
- Metabolic adaptation: when to add cardio vs reduce calories
- Cardio progression: start with minimum effective dose, add gradually
- Reverse dieting: how to reduce cardio volume after fat loss phase

### Heart Health Protocol
- VO2max improvement: specific intervals for cardiovascular adaptation
- Blood pressure management: type and duration of cardio that helps most
- Resting heart rate targets: tracking improvement over weeks
- Heart rate variability: using HRV to guide training intensity decisions
- Long-term cardiovascular health: minimum dose for health vs performance

## OUTPUT FORMAT
Complete cardio program with weekly schedule, HIIT workout designs, steady-state guidelines, heart rate zone targets, and progression plan.

## CONSTRAINTS
- HIIT should not exceed 3 sessions per week to prevent overtraining
- Include proper warm-up and cool-down for every session
- Account for age, orthopedic limitations, and cardiac health conditions
- Don't sacrifice muscle-building goals with excessive cardio
- Include recovery metrics to monitor (resting HR, sleep quality, energy levels)