RAST Calculator - Running Based Anaerobic Sprint Test

What is the Running Based Anaerobic Sprint Test (RAST)?

The Running Based Anaerobic Sprint Test (RAST) was devised at the University of Wolverhampton in the UK by Nick Draper and Greg Whyte in 1997. This test provides a running-based alternative to the Wingate 30-second cycle test, specifically designed to measure anaerobic power and capacity during repeated sprint efforts that closely mimic multi-sprint sports.

The RAST protocol involves six maximal sprints over 35 meters with a 10-second recovery between each sprint. This test provides comprehensive measurements of peak power, average power, minimum power, and a fatigue index that quantifies an athlete's ability to resist power decline during repeated high-intensity efforts.

How to Use the RAST Calculator

Follow these steps to calculate your RAST results:

1. Enter Your Weight: Input your body weight using the metric (kg) or imperial (lbs) toggle. Athletic weight classes typically range from 60kg (lightweight) to 90kg+ (heavyweight).
2. Record Sprint Times: Enter the time in seconds for each of your six 35-meter sprints. Times typically range from 4.5 seconds (elite sprinters) to 7+ seconds (recreational athletes).
3. Calculate Results: Click "Calculate RAST Results" to instantly see your power output for each sprint, peak power, average power, and fatigue index.
4. Interpret Performance: Review the detailed analysis showing your anaerobic capacity category (Elite, Excellent, Good, Average) and fatigue resistance classification.
5. Track Progress: Save or share your results to monitor improvements over training cycles. Re-test every 4-6 weeks during intensive training blocks.

Understanding Your RAST Results

Peak Power (Watts)

Peak power represents your highest power output across all six sprints, typically achieved during sprint 1 or 2 before significant fatigue sets in. This metric reflects your maximal anaerobic capacity and explosive power potential. Elite multi-sprint athletes often generate peak power exceeding 1,000 watts, while trained recreational athletes typically produce 500-800 watts depending on body weight.

Relative Peak Power (W/kg)

Relative peak power normalizes your power output by dividing peak power by body weight, allowing fair comparison across different athlete sizes. This is the most important RAST metric for evaluating sprint quality:

• Elite: >17 W/kg - Top 5% of multi-sprint athletes
• Excellent: 14-17 W/kg - Top 20% of trained athletes
• Good: 11-14 W/kg - Above average for competitive athletes
• Average: 8-11 W/kg - Typical recreational athlete range
• Below Average: <8 W/kg - Focus on sprint power development

Average Power (Watts)

Average power across all six sprints indicates your sustained anaerobic capacity. Athletes with high average power relative to peak power demonstrate good fatigue resistance and anaerobic endurance. The average power should typically be 70-85% of peak power for well-trained athletes.

Fatigue Index (W/s)

The fatigue index quantifies how much your power declines throughout the test, calculated as (Peak Power - Minimum Power) ÷ Total Time. Lower values indicate better repeated sprint ability:

• Excellent: <8 W/s - Elite fatigue resistance
• Good: 8-10 W/s - Strong repeated sprint ability
• Average: 10-12 W/s - Typical for trained athletes
• Needs Improvement: >12 W/s - Focus on anaerobic endurance

The Science Behind RAST Calculations

The Formula

The RAST calculator uses the following validated formula developed by Draper and Whyte:

Power (Watts) = Weight (kg) × Distance² (m) ÷ Time³ (s)

Where:

• Weight: Athlete's body weight in kilograms
• Distance: 35 meters (fixed for RAST protocol)
• Time: Sprint time in seconds

Additional calculations include:

• Peak Power: The highest power value from all six sprints
• Relative Peak Power: Peak Power ÷ Body Weight (W/kg)
• Average Power: Sum of all six power values ÷ 6
• Fatigue Index: (Peak Power - Minimum Power) ÷ Total Time for 6 sprints

Why This Formula Works

According to sports science expert Robert Wood, who has analyzed sports performance data for over 25 years, the RAST formula accounts for the exponential relationship between sprint time and power output. The cubic relationship with time (Time³) reflects the physics of acceleration and deceleration during maximal sprints. The squared distance term (Distance²) accounts for the work done against air resistance and the energy required to accelerate body mass.

Calculation Example

Let's calculate power for an example sprint:

• Athlete Weight: 75 kg
• Sprint Distance: 35 meters
• Sprint Time: 5.00 seconds

Step 1: Calculate Distance² = 35 × 35 = 1,225 m²
Step 2: Calculate Time³ = 5.00 × 5.00 × 5.00 = 125 s³
Step 3: Power = 75 × 1,225 ÷ 125 = 735 Watts

This athlete generated 735 watts of power, or 9.8 W/kg relative power (735 ÷ 75 = 9.8), placing them in the "Average" category for trained athletes.

Accuracy and Limitations

The RAST provides estimates with approximately ±5% accuracy for trained athletes when conducted under standardized conditions. Factors that may affect accuracy include:

• Timing Method: Electronic timing gates provide greater accuracy than stopwatches (±0.01s vs ±0.20s)
• Surface Type: Track surface quality affects sprint times; use consistent surfaces for re-testing
• Environmental Conditions: Wind, temperature, and altitude can influence performance
• Fatigue State: Prior training load significantly impacts results; standardize rest periods
• Warm-up Quality: Inadequate preparation reduces power output and increases injury risk

Sport-Specific Applications of RAST

Basketball

Basketball players require exceptional repeated sprint ability for fast breaks, defensive transitions, and continuous up-down court movements. Elite basketball players typically achieve relative peak power of 15-18 W/kg with fatigue indices below 9 W/s. Guards generally show better fatigue resistance than forwards and centers due to different training adaptations and body compositions.

Football (Soccer)

Soccer midfielders and wingers perform 150-250 high-intensity actions per match, making RAST highly relevant. Research by Robert J. Wood, PhD in Exercise Physiology from the University of Western Australia, indicates that elite soccer players maintain 13-16 W/kg throughout the competitive season. Forward players often show higher peak power but greater fatigue indices than midfielders who are adapted for sustained high-intensity work.

Rugby and American Football

Contact sport athletes typically carry higher body mass but must maintain explosive power for tackles, rucks, and short sprints. Rugby backs achieve 14-17 W/kg, while forwards average 11-14 W/kg. American football skill position players (running backs, receivers) target similar ranges to rugby backs, while linemen focus on absolute power rather than relative power metrics.

Ice Hockey

Hockey players perform high-intensity shift work with short recovery periods, similar to RAST protocol. Elite hockey forwards generate 15-17 W/kg with excellent fatigue resistance (FI <8 W/s). The test effectively predicts on-ice performance during third-period play when fatigue is highest.

Field Hockey

Field hockey requires sustained sprint efforts throughout 60-70 minutes of play. Top-level field hockey players achieve 13-15 W/kg with strong repeated sprint ability. The RAST correlates well with match performance metrics including distance covered at high speed and number of sprints completed.

How to Improve Your RAST Performance

Developing Peak Power

To increase peak power output, focus on maximal sprint training with full recovery:

• Flying Sprints: 10-20 meter flying start sprints at 100% intensity with 3-5 minutes recovery. Perform 6-8 reps, 2x per week.
• Resisted Sprints: Sled pulls or hill sprints (20-30m) at 85-95% max speed. Load should reduce speed by 10-20%. 4-6 reps with full recovery.
• Olympic Lifts: Power cleans, hang cleans, and snatches develop explosive hip extension crucial for sprint acceleration. 3-5 reps at 70-85% 1RM.
• Plyometrics: Depth jumps, box jumps, and bounding exercises improve reactive strength. 30-60 contacts per session, 2x weekly.

Improving Fatigue Resistance

Reduce your fatigue index through repeated sprint training:

• RAST-Specific Training: 6-10 × 30-40m sprints with 20-30 second recovery. Build from 6 to 10 reps over 4-6 weeks.
• Interval Training: 8-12 × 200-400m at 85-95% effort with 1:1 work-rest ratio. Develops anaerobic capacity and lactate tolerance.
• Small-Sided Games: Sport-specific conditioning through reduced-field games with high-intensity periods. 3-5 minute bouts with 2-3 minute recovery.
• Recovery Runs: Light 20-30 minute jogs between sprint sessions enhance lactate clearance and adaptation.

Training Periodization

Structure your RAST improvement program in phases:

Phase 1 - Base Development (4-6 weeks):

• Focus: Build aerobic base and muscular endurance
• Volume: High (12-15 sessions per week including all training)
• Intensity: Moderate (60-75% max effort)
• Sprint Work: Technique-focused with full recovery

Phase 2 - Power Development (4-6 weeks):

• Focus: Maximize peak power and explosive strength
• Volume: Moderate (10-12 sessions per week)
• Intensity: High (85-100% max effort)
• Sprint Work: Maximal sprints with full recovery (3-5 minutes)

Phase 3 - Repeated Sprint Ability (4-6 weeks):

• Focus: Develop fatigue resistance and anaerobic capacity
• Volume: Moderate-High (11-14 sessions per week)
• Intensity: Very High (90-100% max effort)
• Sprint Work: Multiple sets of repeated sprints with incomplete recovery

Phase 4 - Competition/Maintenance (duration varies):

• Focus: Maintain adaptations through sport-specific work
• Volume: Sport-dependent
• Intensity: Mixed based on competition schedule
• Sprint Work: Integrated into practice and matches

Nutritional Considerations

Research by Robert Wood indicates that optimal RAST performance requires adequate energy availability and strategic nutrient timing:

• Pre-Test Nutrition: Consume 1-2g carbohydrate per kg body weight 2-3 hours before testing. Include moderate protein (20-30g) for sustained energy.
• Hydration: Maintain euhydrated state. Dehydration of just 2% body weight impairs high-intensity performance by 10-20%.
• Recovery Nutrition: Within 30 minutes post-RAST, consume 20-25g high-quality protein and 1-1.2g carbohydrate per kg to optimize recovery and adaptation.
• Creatine Supplementation: 5g daily creatine monohydrate may enhance peak power and repeated sprint performance. Load with 20g/day for 5 days, then maintain at 5g/day.

RAST Testing Protocol

Equipment Required

• Timing System: Electronic timing gates (preferred) or stopwatch accurate to 0.01 seconds
• Measuring Tape: To accurately mark 35-meter course
• Marker Cones: To clearly identify start and finish lines
• Track Surface: Flat, dry track or field with good traction
• Scale: To measure body weight before testing
• Timing Personnel: Two testers (one for sprint time, one for recovery period)

Pre-Test Procedures

1. Health Screening: Complete PAR-Q or similar screening. RAST is maximal effort and contraindicated for individuals with cardiovascular conditions.
2. Standardize Conditions: Record environmental conditions (temperature, humidity, wind). Test at same time of day for re-testing.
3. Measure Body Weight: Weigh athlete in minimal clothing before warm-up for accurate power calculations.
4. Course Setup: Mark 35-meter course with cones at each end. Add 5-meter run-in and run-out zones if using manual timing.

Warm-Up Protocol

A thorough warm-up is critical for safety and optimal performance:

1. General Warm-Up (5-7 minutes): Light jogging to raise core temperature and increase blood flow
2. Dynamic Stretching (5-7 minutes): Leg swings, walking lunges, high knees, butt kicks, A-skips, B-skips
3. Progressive Sprints (5-7 minutes):
   • 2 × 35m at 50% effort
   • 2 × 35m at 70% effort
   • 2 × 35m at 85% effort
   • 1 × 35m at 95% effort
4. Final Preparation (2-3 minutes): Mental preparation and final adjustments. Begin test within 5 minutes of last warm-up sprint.

Test Execution

1. Starting Position: Athlete stands at start line using preferred starting stance (standing or 3-point)
2. Sprint 1: On "go" command, sprint maximally through 35m finish line. Timer records time to nearest 0.01s
3. Recovery Period: Second timer counts exactly 10 seconds while athlete walks back slowly
4. Sprints 2-6: Repeat from opposite end of course. Alternate direction each sprint
5. Encouragement: Provide strong verbal encouragement to ensure maximal effort on each sprint
6. Safety: Ensure adequate run-out space beyond finish line. Stop test if athlete shows signs of distress

Common Testing Errors

• Inadequate Warm-Up: Increases injury risk and reduces performance by 5-15%
• Inconsistent Recovery Time: Variations in 10-second recovery period affect fatigue index accuracy
• Submaximal Effort: Athletes must sprint through the line each time, not to the line
• Poor Course Marking: Inaccurate distance measurements invalidate power calculations
• Unfavorable Conditions: Strong headwinds or wet surfaces significantly impact times