Exercise & Physical Activity

Exercise as a Circadian Signal

While not as powerful as light, physical activity is an important zeitgeber (time-giver) that can influence your circadian rhythm. Exercise affects body temperature, hormone production, and metabolism—all components of your internal clock. Strategic exercise timing can complement your light exposure and sleep strategies to speed up jet lag adjustment.

How Exercise Affects Your Circadian Rhythm

Physiological Mechanisms

• Body Temperature: Exercise raises core body temperature, which is a circadian marker
• Hormone Release: Affects cortisol, melatonin, and growth hormone timing
• Metabolic Activation: Signals "active time" to your body
• Sleep Pressure: Increases adenosine buildup, promoting sleep consolidation
• Alertness: Immediate boost to wakefulness and cognitive function

The Phase Response to Exercise

Similar to light, exercise effects depend on timing:

• Morning/early afternoon exercise: Tends to advance circadian phase (shift earlier)
• Evening exercise: Can delay circadian phase (shift later), though effects are more variable
• Late night exercise: Generally not recommended as it may interfere with sleep onset

Exercise Strategies for Eastward Travel

When traveling east, you need to advance your circadian phase (shift earlier).

Before Departure

• Exercise in the morning: Workout right after waking or in early morning
• Intensity: Moderate to vigorous exercise is most effective
• Outdoor if possible: Combines exercise with morning bright light exposure
• Duration: 30-45 minutes of aerobic activity
• Avoid evening workouts: Can delay your rhythm when you want to advance it

After Arrival

• Exercise in destination morning: Reinforces the advance in your schedule
• Outdoor activities: Walking tours, jogging, outdoor sports combine light and exercise
• Stay active during day: Even light activity helps maintain alertness
• Avoid intense exercise close to bedtime: Stop vigorous activity 3-4 hours before sleep

Exercise Strategies for Westward Travel

When traveling west, you need to delay your circadian phase (shift later).

Before Departure

• Exercise in the evening: Late afternoon or early evening workouts
• Intensity: Moderate intensity helps you stay up later without over-stimulation
• Social sports: Group activities provide both exercise and social zeitgebers
• Avoid early morning workouts: Can advance your rhythm when you want to delay it

After Arrival

• Exercise in late afternoon/evening: Helps you stay alert until destination bedtime
• Active evening activities: Walks, light sports, dancing
• Avoid morning exercise first few days: Let yourself sleep in initially

Exercise During Travel

Before the Flight

• Light to moderate exercise: Reduces pre-flight stress and anxiety
• Don't exhaust yourself: You'll need energy for the journey
• Stretching and mobility: Prepares body for extended sitting
• Timing: Exercise 2-4 hours before flight for optimal alertness

During the Flight

• Move every 1-2 hours: Walk the aisles, even just to the bathroom and back
• In-seat exercises: Ankle circles, leg lifts, shoulder rolls, neck stretches
• Compression socks: Helps circulation during long periods of sitting
• Stay hydrated: Supports circulation and reduces fatigue
• Avoid alcohol: Worsens dehydration and impacts sleep quality

After Landing

• Light activity immediately: Walk through airport rather than using moving walkways
• Don't rush to hotel: If arriving in morning, stay active and outside
• Gentle stretching: Relieves stiffness from flight
• Resist urge to collapse: Light movement fights drowsiness better than sitting

Types of Exercise for Jet Lag Management

Aerobic Exercise

Best for circadian shifting and alertness:

• Running/jogging: Outdoor preferred for light exposure benefit
• Walking: Low impact, easy to do while sightseeing
• Cycling: Outdoor exploration combined with exercise
• Swimming: Good if your hotel has a pool
• Dancing: Social activity with exercise benefit

Resistance Training

Useful but less studied for circadian effects:

• Can be done in hotel gym with limited equipment
• Bodyweight exercises (push-ups, squats) require no equipment
• Maintains strength during travel
• May be less effective than aerobic for circadian shifting

Yoga and Stretching

Good for flexibility and stress relief:

• Morning yoga: Energizing sequences help wake you up
• Evening yoga: Gentle, restorative sequences aid relaxation
• Stretching: Relieves travel-related stiffness
• Breathing exercises: Reduces anxiety, improves focus

High-Intensity Interval Training (HIIT)

Time-efficient but timing-sensitive:

• Very effective for waking up the body
• Can be done in 15-20 minutes
• May be too stimulating close to bedtime
• Best for morning circadian advancement

Exercise Intensity Guidelines

For Promoting Alertness

• Moderate to vigorous intensity: 60-80% max heart rate
• Duration: 20-45 minutes
• Timing: When you need to be awake but feel drowsy
• Effect: Immediate boost in alertness lasting 2-4 hours

For Sleep Promotion

• Moderate intensity earlier in day: Increases sleep pressure
• Avoid within 3 hours of bedtime: Can delay sleep onset
• Light evening yoga/stretching: Acceptable close to bedtime
• Consistency matters: Regular exercise improves overall sleep quality

Practical Exercise Tips for Travelers

Overcoming Barriers

• No gym access: Bodyweight exercises, walk/jog outside, hotel room workouts
• Limited time: Even 10-15 minutes of movement helps
• Fatigue: Light exercise can actually boost energy; start easy
• Unfamiliar location: Hotel concierge can suggest safe walking/running routes
• Weather concerns: Mall walking, hotel stairs, indoor activities

Packing for Exercise

• Athletic shoes (can double as walking shoes)
• Lightweight exercise clothes
• Resistance band (portable strength training)
• Jump rope (hotel room cardio)
• Swimming suit if hotel has pool

Safety Considerations

• Know your route: Research safe areas for outdoor exercise
• Stay visible: Reflective gear if exercising in dark
• Hydration: Especially important in new climates
• Listen to your body: Don't push too hard when jet-lagged
• Medical conditions: Consult doctor about exercise during travel if you have health concerns

Combining Exercise with Other Strategies

Exercise + Light Exposure

Most powerful combination:

• Outdoor morning exercise for eastward travel
• Evening outdoor activity for westward travel
• Walk or jog in bright sunlight
• Outdoor sports and activities

Exercise + Social Interaction

• Group fitness classes
• Team sports
• Walking tours with others
• Social zeitgebers reinforce circadian signals

Exercise + Meal Timing

• Exercise before meals can help regulate appetite timing
• Post-exercise meals on destination schedule
• Avoid heavy meals immediately before exercise

Special Considerations

Business Travelers

• Schedule morning workouts before meetings
• Use hotel gym during conference breaks
• Walking meetings when possible
• Stairs instead of elevators

Athletes and Performance

• Arrive several days early for competitions
• Gradually shift training times before travel
• Maintain training intensity once adjusted
• Light training during adjustment period

Older Adults

• Lower intensity, longer duration
• Focus on walking and gentle activities
• Balance and flexibility exercises
• May need more gradual adjustment

Common Mistakes to Avoid

• Exercising at the wrong time: Can shift rhythm in opposite direction
• Too intense when exhausted: Listen to your body, start light
• Skipping exercise entirely: Even light activity helps
• Late-night intense workouts: Can interfere with sleep initiation
• Not combining with light exposure: Miss opportunity for synergistic effects
• Ignoring safety: Research safe routes in unfamiliar locations

Key Takeaway: Exercise is a valuable tool for jet lag management, especially when combined with strategic light exposure. Time your workouts according to your travel direction, stay active throughout your trip, and use movement to boost alertness when needed.