Anaerobic exercise involves short bursts of high intensity activity, as opposed to lower intensity aerobic exercise. Examples of anaerobic exercise include sprinting, weightlifting, and high intensity interval training (HIIT). Anaerobic exercise is fueled by the phosphagen system and glycolysis, which do not require oxygen. As a result, anaerobic exercise can only be sustained for a short period of time before fatigue sets in. Typically, anaerobic exercise bursts last anywhere from 10 seconds to 2 minutes. After each anaerobic burst, it is important to allow for an adequate rest period before the next bout of exercise. The optimal rest period allows the body to briefly recover and replenish energy systems in order to perform the next anaerobic burst at maximum effort. This article will provide guidelines on recommended rest period lengths between anaerobic exercise intervals based on the goal of the training session.
Rest Period Length Depends on Goal of Session
The ideal rest interval between anaerobic bursts depends largely on the goals of the workout or training program. Some key goals include:
Maximal Power Output
For developing maximal mechanical power and strength, longer rest periods of 3-5 minutes are recommended between sets and reps. This allows for near complete ATP and phosphocreatine recovery, which provides energy for maximal power output.
Muscular Hypertrophy
For increasing muscle size, rest periods of 1-2 minutes between sets allows for partial recovery. Metabolic stress from incomplete rest contributes to muscle growth.
Muscular Endurance
For improving the ability to sustain near maximal power, shorter rest intervals of 30-90 seconds between bursts are ideal. This taxes both the ATP-PC and glycolytic energy systems.
Increasing Anaerobic Capacity
For improving the maximum accumulated oxygen deficit and tolerance to metabolic acidosis, use 30-60 second rest intervals. This maximizes glycolytic metabolism.
Improving VO2max
For enhancing aerobic power by improving VO2max, use rest intervals of 1-2 minutes between high intensity sprints. This allows partial recovery before the next sprint.
Fat Loss
For optimizing fat burning, use shorter rest intervals of 30-60 seconds between bursts. This sustains exercise intensity and an elevated metabolism.
General Recommendations Based on Work Interval
As a general rule of thumb, the shorter the anaerobic work interval, the shorter the rest period should be between bursts. Here are general recommendations:
10-30 Second Intervals
Rest 30-60 seconds between bursts
30-60 Second Intervals
Rest 1-2 minutes between bursts
1-2 Minute Intervals
Rest 2-3 minutes between bursts
2-5 Minute Intervals
Rest 3-5 minutes between bursts
However, these recommendations should be tailored to the individual and goals of the training session. Some additional factors that can influence the ideal rest period length include fitness level, training status, recovery ability, and use of recovery modalities.
Recovery Modalities Can Shorten Rest Periods
Various recovery modalities can be used in conjunction with anaerobic interval training to help speed recovery between bursts and allow for shorter rest periods. These include:
Active Recovery
Performing light aerobic activity between intervals helps remove metabolic byproducts and sustain blood flow. This enhances recovery for the next burst.
Hydration
Drinking fluid and electrolytes helps replace sweat losses and combats fatigue. This aids recovery.
Cool Down
A brief cool down after a work interval helps gradually reduce heart rate and clear waste products.
Massage
Massage helps increase blood flow to working muscles, enhancing recovery ability.
Compression
Compression gear worn after intervals helps facilitate venous return and waste product removal.
Nutrition
Consuming protein and carbs aids muscle recovery and replenishes glycogen stores for the next interval.
By optimizing these strategies during the rest period, athletes can decrease fatigue and improve performance within a training session.
Rest Period Length and Training Phase
The appropriate rest interval also depends on the phase of training:
Offseason or General Preparation Phase
Longer rest intervals should be prescribed during offseason training when the focus is on muscle growth, maximal strength development, and power enhancement. Rest periods of 2-5 minutes are ideal.
Pre-Competition or Specific Preparation Phase
As competition approaches, rest intervals should decrease to match the demands of the sport or event. For example, MMA fighters would use 30-90 sec rest periods in this phase.
Competition Phase
In-season, the rest period length should mimic the intervals seen in actual competition. This maximizes specific performance. For example, wrestlers may use 20-30 sec rests.
Transition Phase
The post-season phase should focus on active recovery and metabolic clearance between intervals. Shorter intervals of 30-60 sec are appropriate here.
The phase of training dictates metabolic demands and recovery ability and should guide appropriate rest period prescription.
Factors that Influence Ideal Rest Period Length
There are several key factors that impact how much rest is required between anaerobic bursts:
Intensity of the Work Interval
The higher the exercise intensity, the longer the recovery period should be between intervals to allow the ATP-PC and glycolytic systems to replenish.
Type of Exercise
Full body exercises like sprints require longer rest intervals than isolation exercises like bicep curls. Systemic fatigue accrues faster with total body moves.
Number of Muscle Groups Worked
Intervals using multiple large muscle groups demand longer rest periods compared to smaller muscle groups to facilitate recovery.
Mechanical Load
Heavier loading requires longer rest to allow muscles, connective tissue and the nervous system to recuperate before the next interval.
Athlete’s Fitness Level
Well trained athletes can handle shorter rest periods due to greater work capacity and recovery ability compared to less fit individuals.
The combination of these factors help determine optimal rest prescription.
Sample Rest Intervals for Different Training Goals
Here are sample rest period prescriptions for different anaerobic workout scenarios:
Maximal Strength
3-5 minutes rest between heavy weightlifting sets utilizing 85-100% 1RM loads.
HIIT Workout
1-2 minutes rest between 30 second all-out sprints.
Plyometric Leg Workout
2-3 minutes rest between sets of explosive box jumps, lunge jumps, and squat jumps.
Upper Body Power
2-3 minutes rest between sets of medicine ball chest passes and plyometric push-ups.
Metabolic Resistance Training
45-60 seconds rest between sets of multi-joint kettlebell, dumbbell, and bodyweight exercises performed as a circuit.
MMA Fight Preparation
60-90 seconds rest between rounds of heavy bag work, mitt drills, and burpees.
Basketball Speed & Agility
90-120 seconds rest between suicides, reaction sprints, and lateral shuffle intervals.
Conclusion
In summary, the ideal rest period length between anaerobic exercise intervals depends on the goals of the training session, the work interval intensity and duration, the amount of muscle mass involved, and the fitness level of the athlete. While general recommendations provide a starting point, the rest interval should be adjusted as needed based on individual response. Optimal recovery between bursts allows maximal performance and adaptation within each training session.
