Anaerobic Power Intervals: Understanding, Principles, and Training Protocols

What are the intervals for anaerobic power?

Anaerobic power intervals are characterized by very short, maximal effort work periods, typically lasting between 5 and 15 seconds, followed by significantly longer rest periods to allow for near-complete replenishment of the phosphocreatine (PCr) system, often at a work-to-rest ratio of 1:3 up to 1:12 or more.

Understanding Anaerobic Power

Anaerobic power refers to the maximum rate at which the body can produce energy (ATP) without the use of oxygen. This energy production primarily relies on the alactic or phosphagen system (ATP-PCr system), which provides immediate, high-intensity energy for very short bursts of activity. Unlike anaerobic capacity, which relates to the total amount of work that can be done anaerobically (often relying on the glycolytic system), anaerobic power focuses on the peak rate of force or velocity production. Training anaerobic power aims to enhance the efficiency and capacity of the ATP-PCr system, leading to improvements in explosive movements like sprinting, jumping, and heavy lifting.

The Science Behind Anaerobic Power Training

To effectively train anaerobic power, it's crucial to understand the energy systems involved:

• ATP-PCr System (Alactic System): This system provides ATP for the first 0-15 seconds of maximal effort. It uses stored ATP and phosphocreatine (PCr) within the muscle cells. PCr rapidly donates a phosphate group to ADP (adenosine diphosphate) to reform ATP. This process is very fast and does not produce lactic acid, hence "alactic." For maximal power output, this system must be the primary energy source.
• Glycolytic System (Lactic System): As exercise extends beyond 15-30 seconds, the glycolytic system becomes more dominant. It breaks down glucose and glycogen to produce ATP, yielding more ATP than the ATP-PCr system but at a slower rate and producing lactate as a byproduct. While contributing to anaerobic capacity, its involvement should be minimized during pure anaerobic power training to ensure the highest possible intensity from the ATP-PCr system.

The goal of anaerobic power intervals is to repeatedly stress the ATP-PCr system at its maximal output, then allow sufficient recovery for PCr stores to replenish before the next maximal effort.

Defining Anaerobic Power Intervals

Effective anaerobic power intervals are precisely structured to target the ATP-PCr system and maximize its output. Key parameters include:

• Work Duration:
  • To specifically target the ATP-PCr system, work bouts must be very short.
  • Typical durations range from 5 to 15 seconds. Efforts longer than 15-20 seconds begin to significantly recruit the glycolytic system, shifting the training stimulus towards anaerobic capacity rather than peak power.
• Intensity:
  • The work must be performed at maximal or near-maximal effort (95-100% of perceived maximal exertion). This is non-negotiable for power development. If intensity drops, the stimulus for power adaptation is lost.
• Rest Duration:
  • Recovery periods must be long enough to allow for substantial (ideally 85-95% or more) replenishment of PCr stores.
  • PCr replenishment is rapid initially but slows down. It takes approximately 30 seconds for 70% replenishment and 3-5 minutes for near-complete (90-95%+) replenishment.
  • Therefore, rest intervals are typically 3 to 12 times the work duration, resulting in work-to-rest ratios like 1:3, 1:6, 1:10, or even 1:12. For a 10-second sprint, this could mean 30 seconds to 2 minutes of rest.
  • Passive recovery (standing or light walking) is generally preferred over active recovery during these short, intense intervals to maximize PCr resynthesis.
• Number of Repetitions/Sets:
  • The total number of repetitions and sets depends on the specific exercise, the athlete's fitness level, and the rest duration.
  • Since each effort is maximal, the total volume of work per session is relatively low to prevent fatigue from compromising power output.
  • Typically, 3-8 repetitions per set and 2-5 sets are used, with adequate rest between sets (e.g., 5-10 minutes).

Specific Interval Protocols for Anaerobic Power

While the principles remain constant, various protocols can be employed:

• Classic Wingate-Style Intervals (Modified):
  • Work: 30 seconds maximal effort (though for pure power, a shorter 5-10 second burst is often used within a Wingate-like test).
  • Rest: 4-5 minutes passive recovery.
  • Reps/Sets: 4-6 repetitions.
  • Note: A true 30-second Wingate test assesses anaerobic capacity more broadly. For power, focus on the initial 5-10 seconds of a Wingate-like effort.
• Short Sprint Intervals:
  • Work: 5-10 seconds maximal sprint (e.g., 40-100 meters).
  • Rest: 60-120 seconds passive recovery (1:6 to 1:12 ratio).
  • Reps/Sets: 6-10 repetitions per set, 2-4 sets.
• Plyometric Power Intervals:
  • Work: 5-10 seconds of maximal effort plyometrics (e.g., repeated broad jumps, box jumps, depth jumps).
  • Rest: 45-90 seconds passive recovery.
  • Reps/Sets: 4-8 repetitions per set, 2-4 sets.
• Resistance Training Power Intervals:
  • Work: 3-5 repetitions of an explosive lift (e.g., power cleans, snatches, jump squats with light load) performed with maximal concentric velocity. Total time under tension should be 5-10 seconds.
  • Rest: 2-5 minutes between sets.
  • Reps/Sets: 3-5 sets.

Practical Application and Programming Considerations

When incorporating anaerobic power intervals into a training program, consider the following:

• Exercise Selection: Choose exercises that allow for maximal, explosive effort and recruit large muscle groups. Examples include track sprints, cycling sprints, plyometrics (jumps, bounds), and Olympic weightlifting variations.
• Warm-up: A thorough warm-up is critical. This should include general cardiovascular activity, dynamic stretching, and specific drills that mimic the movements of the main workout at lower intensities.
• Technique: Prioritize perfect technique over volume. Fatigue compromises technique, which can increase injury risk and reduce training effectiveness.
• Progression: Progress by gradually increasing the number of repetitions or sets, or slightly reducing rest periods only if power output can be maintained. Do not sacrifice intensity for volume.
• Recovery and Adaptation: Anaerobic power training is highly demanding on the nervous system. Allow adequate recovery between sessions (48-72 hours) to facilitate supercompensation and prevent overtraining. Incorporate active recovery, proper nutrition, and sufficient sleep.
• Periodization: Integrate anaerobic power training into a well-designed periodized program, often during a pre-competition or power-focused phase, after a foundational strength phase.
• Safety: Due to the maximal nature of these efforts, ensure proper supervision, especially for complex movements or high-impact activities.

Conclusion

Anaerobic power intervals are a potent training method for enhancing explosive strength and speed. By adhering to specific work durations (5-15 seconds), maximal intensity, and generous rest periods (1:3 to 1:12+ work-to-rest ratios), athletes and fitness enthusiasts can effectively target and improve the phosphocreatine energy system. Implementing these principles with appropriate exercise selection and careful programming will yield significant gains in performance for activities requiring short, powerful bursts of energy.