Articles

Active Recovery

September 14, 2012

A review of how active recovery can help performance post race or training Active recovery (AR) refers to engaging in low-intensity exercise after workouts during both the cool-down phase immediately after a hard effort or workout as well as during the days following the workout

Building recovery time into any training program is important because this is the time that the body adapts to the stress of exercise and the real training effect takes place. High intensity exercise can cause muscle damage which is associated with decreases in muscle function and performance, a perceived increase in soreness and tenderness, a reduction in flexibility, and alterations in muscle sequencing and recruitment patterns.

AR is thought to work by increasing blood flow and enhancing clearance of enzymes responsible for muscle damage. It is also though to help increase range of movement in the affected area

In this article we a quick look at the research on AR during and post exercise.

Recovery between short bouts of high intensity exercise

Short bouts of high intensity exercise increase lactate levels which have been shown to inhibit muscle performance and cause premature fatigue. Studies that have compared active recovery to passive recovery (complete rest) have found that in the first few minutes of a recovery period there was no difference in lactate clearance levels between both, but that after 15-20 minutes lactate clearance was higher in the groups performing active recovery compared to the group doing passive recovery.

Lactate is removed through several organs in the body and a significant amount is removed by skeletal muscle. It is thought that during short term high intensity bouts of exercise, skeletal muscle becomes rapid producers of lactate and as a result the clearance of lactate is slowed down. Later during recovery there is a transition to a net removal of lactate by the muscles and this transition period between production and removal of lactate may explain why it takes approx. 10 mins for active recovery to have an effect on lactate levels.

While lactate levels may not be affected for recovery periods under 10 minutes, AR can have a positive effect on performance even during short recovery periods between exercise bouts.
A study compared cyclists doing sessions of high intensity sprint efforts with 3 mins of active or passive recovery between. Lactate, peak power and average power were measured. It was found that as the sessions were performed the decrease in peak and average power was significantly less in the AR group than the passive recovery group despite similar lactate values between both groups. Fairly similar results were found in a swimming studying comparing active recovery, massage and passive recovery. Those who undertook active recovery or massage in a ten minute recovery interval between swim efforts recorded lower lactate levels and better performances than those who underwent passive recovery in the last swim session.

This would suggest that even short periods of active recovery is beneficial between high intensity training efforts in reducing the decrease in peak and average power over the duration of the training session, but in order to reduce lactate levels between exercise efforts longer periods of active recovery (10-15+mins) are required.

Recovery post exercise

Optimising recovery from training performance may benefit the subsequent training and performance over time. Studies on this type of recovery often look at biochemical markers of recovery as well as overall reported feelings of wellness. In many studies, the levels of an enzyme (creatine kinase) thought to be produced as a result of muscle damage is tracked as an indicator of recovery. The levels of this enzyme increase rapidly after strenuous exercise, and there has found to be a correlation between this and max peak force produced by a muscle

In studies examining the effect of active recovery of rugby players, it was found that those that the players who under took active recovery straight after a strenuous match showed 88% recovery to normal creatine kinase levels compared with 39% of those who just rested when retested 84 hours after the match. The rate of recovery was similar to that of active recovery for the players who wore compression garments for 12 hours, and those who underwent contrast water therapy (See earlier article for an explanation of water therapy)

Another point of interest from this study is the time it took for recovery of creatine kinase levels to return to close to normal. At 3.5 days (84hrs) the creatine kinase levels were only 88% recovered in the AR group and 39% recovered in the passive group. This accounts for the negative impact on performance often experienced in the days after the exercise and the associated negative psychological impact it can have (legs not feeling fresh, training sessions feeling harder than expected). This highlights the importance of modifying exercise intensity towards easier training sessions for 5-10 days after strenuous exercise to prevent injury. For normal exercise levels recovery of 1-2 days is recommended in the literature.

Regarding the feeling of wellness, the effect of active recovery on muscle soreness post exercise found that active recovery decreased muscle soreness and tenderness by 40% compared to passive recovery. In addition the part of the body exercised in active recovery is found to be important. In a study performed on Slalom canoeists, a sport that works the arms heavily, it was found that those who undertook active leg recovery by cycling had better lactate recovery that those who performed light arm recovery on an arm ergometer.

Conclusion

It is recommended that the intensity and duration of exercise is reduced 1-2 days after a hard training session or a competition. Recovery days are necessary as part of any training programme to allow the body to adapt to the training load. If overload is allowed to occur over a period of time it will result in exhaustion and injury. On rest days active recovery would involve carry out light low intensity exercise for 20-30 minutes i.e. zone 1 type effort where a conversation can be held with ease or 40% VO2max. Longer periods deplete energy stores and cause fatigue. You are doing it right if your legs feel lighter afterwards, and on the wrong track if your legs feel heavy.

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