The first article, by Toubekis et al. (pp. 109-116), examined the effects of passive and active rest on repeated swim sprint speed:
10 male competitive swimmers averaging 18 years of age performed eight 25-meter swim sprints separated by 2 minute recovery periods. After the last 25-m sprint, a 6 minute recovery period was provided before a single 50-meter sprint. On different occasions each subject’s recovery periods were as follows:
- A - passive rest
- B - swimming continuously at 40% of the maximum velocity they could sustain for 100-m.
- C - swimming continuously at 60% of the maximum velocity they could sustain for 100-m.
- Statistically, the passive recovery and 40% of max speed recovery produced significantly faster 25-m times than did the 60% of max speed recovery.
- The average 25-m time with the passive recovery was faster than the time with the 40%-max recovery. However, the difference did not reach statistical significance.
- There was no statistically significant difference between recovery methods for the 50-m sprint.
The second article, by Miladi et al. (pp. 205-210) examined the effects of recovery by passive rest, active rest, and dynamic stretching on 4-minute work bouts and subsequent stationary bicycling time to exhaustion.
10 soccer athletes averaging 26 years of age exercised on a stationary bicycle at high intensity (20% higher than the power output they exhibited at their maximal rate of oxygen uptake) 4 times for 30 seconds, with 30 seconds of passive rest in between for a total of 3.5 minutes. They then had a 4 minute recovery period before doing another 3.5-minute exercise bout of the same kind. Following another 4-minute recovery period, they then cycled as long as they could at the same high intensity used in the exercise bouts. On three different occasions the 4-minute recovery periods consisted of:
- passive recovery: no exercise
- active recovery: they kept cycling, but at low intensity (30% of the power output at their maximal rate of oxygen uptake)
- dynamic stretching using 4 different lower body stretches, each done for 30 seconds. Between the stretches, "dynamic awakening" muscular exercises were done.
- Dynamic stretching and active recovery both resulted in significantly longer time until exhaustion (~20%) than passive recovery.
- Dynamic stretching resulted in about 8% longer time until exhaustion than active recovery, but the difference didn't reach statistical significance.
The first study indicates that passive recovery or low-intensity active recovery were most effective for 2-minute recovery periods separating 11.5-13.0 second bouts of swim sprinting. However, the second study found that stretching or active recovery was more effective than passive recovery following 3.5 minute work bouts separated by 4-minute recovery periods. The main difference between the studies lies in the duration of the work bouts and rest periods. The activities also differed - swimming and cycling.
Looking at the results of these two studies and the results of similar studies, it appears that for short sprints (under 20 seconds) and short rest periods (under 3 minutes) passive recovery is most effective, allowing short-term energy stores in the muscles to replenish. However, for longer sprints and longer recovery periods, active recovery or dynamic stretching may be more effective.
Since the effectiveness of a recovery method depends on sprint duration, recovery interval, and type of activity, it seems best for coaches to try the different recovery methods to see which one is most effective for their specific sport program.