The functional effects that you are using "graduated compression" garments are known and used for some time in vascular medicine. The word "graduated" means that the garment is constructed in such a way as to compress (the compression is measurable in mmHg) with greater intensity the peripheral districts of the body, then gradually reduce its action by approaching the heart; The elastic stocking, which decreases its compression in the foot-calf-thigh passage. Even in sports, it is time to take advantage of these properties.
This article introduces a study on the use of these garments to assist in the post-race recovery of the swimmer.
In the sport the first application of a known compression garment was at the 1998 World Cup when French national players wore during elastic socks tournaments with the aim of improving performance through increased oxygenation and more Rapid disposal of toxins in the calf muscle. Next, a great deal of interest has developed on the subject and there has been widespread diffusion in various sports disciplines; At the same time, however, there has been much confusion about the effects and the correct use of this kind of clothing. Multiple research on the topic - over 500 works of scientific interest had already been published in 2013 - did not lead to easy interpretations because of the multiplication of effects of multiple elements such as:
The type of worn clothing (31 different knitwear, tights, overalls, sleeves, shorts, socks, leggings),
The compression level (typically from 10 to 40 mmHg),
The type of sport and the duration of the activity studied (sport of strength, resistance, combat, ...),
The use for which it is worn (before, during, after the race or in the workouts)
At the choice of the best marker to check the fatigue status and hence any effects produced by the dress.
According to several authors, wearing a compression garment during the competition does not lead to an improvement benefit (Doan 2003, Duffield 2008, Ali 2010). The athlete in the race perceives greater proprioceptive control of the movements and less muscular vibration, however showing little effect on the quality and performance of the gesture. Moreover, ethics are highly discussed, particularly in the cycling and athletics disciplines, the advantage that can be gained from wearing this garment in competition because it is considered capable of providing a "non-natural" mechanical action supplementary to the effort of the 'body. Depending on the intensity and duration of the exercise, it may be useful to wear them in particularly stressful and prolonged workouts that can produce stress on the muscles (Chatard 2008). Instead, it is less useful to wear them in the pre-competitive phase, where their effect is primarily directed to maintaining bodily warming. The most interesting indications come from studies that have investigated the action of compression clothing as the adjuvant post-recuperation stage (Jakeman 2010, Born, 2013).
As a result of a sports activity, the training methodology identifies three types of recovery, which we can classify according to their duration:
Immediate recovery, which can be identified in the inevitable breaks to replenish the individual motions that the athlete repeats to train. Swimming, by its motor cyclicity, alternates muscle contractions and decays, and in the latter one identifies immediate recovery.
The second short-term recovery plays a very important role during the refreshment stages in interlocked work blocks and involves all the parameters responding to "first" against stress.
The third long-term (training recovery), takes into account the accumulation of unresistant stress factors and the chronic effects of training.
Swimmers have the problem of recovering the best efforts in close times and in the various stages of competitions. There is therefore a problem of "short-term recovery" - which is indicatively dependent on the subject's level of training and keeps the body altered for about 1.30 / 2 hours in the post-race - but at the same time to the additive effects that Several short-term fatigues determine in the days following the first test.
Among the most commonly used recuperation practices in swimming are the active recovery methods (Toubekis, 2005/2006/2008) - gymnastics / stretching and swelling - and passive recovery - with various types of massages - while you are They are experimenting with other techniques, such as electrostimulation (Neric 2009), temperature-controlled baths and the use of compression costumes. In the latter, the choice of material to be worn is geared to what the market, mainly cycling clothing, provides. Technical development, however, could not go beyond studying a specific material for swimmers, paying particular attention to the peculiarities of the natatorial performance and among these, not least, the different influence of gravity action, with the athlete's body position Which passes from orthostatism to clinostatism. Arena Italia has been studying its compression costume for two years and the final product has been tested in the Laboratory of Engine Science at the University of Bologna.
The protocol defined for the test consisted in monitoring the trend of some fatigue indicators after having performed 12 swimmers of a good level, a maximum swim test on 400m crawl distance. The swim test was repeated on two different days, when wearing the compression costume (Powerskin Recovery Compression, Arena, Macerata, Italy) and once without. The aim was to check whether, wearing the compression cost during the recovery phase, variations (statistically significant: p> 0.05) were observed in the monitored parameters, compared to the control condition ie without wearing the costume. Prior to each test, the baseline was defined as the state of complete resting of the body, monitored in "continuum" for 15 minutes, in a room with comforting temperature, soft lights and no sound disturbances.
The neuro-physiological indicators considered were different Emodynamic Parameters (Pressures, Volumes, Flow, Resistance) and the Autonomic Nervous System (ortho / parasympathetic action).
After the registration of the "baseline" the subjects performed a standardized heating and followed a 400m maximum swimming test, where total and partial times and arm frequencies were measured. At the end of the swim test, the subjects returned to full rest and the recovery phase was monitored. As mentioned above, the same subjects were tested, with the same procedure, in two different days, with and without compression costume. Here are some of the most significant measurements of the different measured parameters.
Graphs (1 and 2) show the dynamics of "blood pressure". In all charts, the first step left on the abscissa axis is the baseline. Next, the time analysis shows the four recovered periods of investigation: from 20 to 30 min, from 40 to 50, from 60 to 70, and from 80 to 90 after the effort. The blue bars indicate the average values of the parameters recorded during the "control" day (without compression costume), while the red ones refer to the day when athletes wore the graduated compression costume.
Figure 1 shows the systolic pressure data (axis of the ordinates in mmHg). It can be noticed that subjects start from a baseline condition but after swimming the athletes who do not wear the costume in the first control (20/30 min) have a mean systolic pressure value down to about 90 mmHg.
After intense physical stress the pressure values decrease (see charts), then back up and return to the baseline condition in about 80/90 minutes. The graph shows how the difference between the baseline pressure values and the recovery control phases is statistically different in the first 3 steps, while wearing the costume this difference is not significant.
Diagram 2 shows the progress of diastolic pressure.
As soon as the effort is over, the diastolic blood pressure of the "control" group drops to 50 mmHg, then reveals a kinetics similar to that previously seen for systolic pressure, but with significant differences compared to the baseline condition in the first 2 steps.
The trends shown in charts 1 and 2 show how the mechanical action of the compression cost has allowed the level of pressure to be "not different" from the baseline, intervening to "support" the homeostatic action involved in post-stress recovery.
Graph 3 shows the kinetics of the NN50. This parameter is indicative of the Parasimpatic Nervous System function measured in the domain of time on the Cardiac Variability parameter. Cardiac Variability (HRV = Heart Rate Variability) is the natural variation in the time between a heart rate and the next. It is also known as RR variability, where R is the peak of the QRS complex of an ECG wave, and for RR the distance between two R peak. The NN50 parameter indicates the number of consecutive intervals (RR) with a difference greater than 50 msec. The analysis of this parameter is a method of assessing the state of the mechanisms of regulation of the physiological functions of the human body. The balance of such systems (Sympathetic And Parasimpatic) determines the ability and type of adaptation to an external stimulus, what is commonly called stress response. Adaptation, whether positive or negative, is based on the degree of disturbance of such mechanisms.
The trend is graphically readable: in the first 2 steps of recovery the difference with the baseline is significant in both conditions (with and without costume) but in the third step (60/70 min after the effort) remains significant only in the condition " Without compression garment. " This means that when subjects wear their costume, they return to the pre-exercise condition in less time than the condition without costume. The mechanical activity of the costume seems to affect cardiac parasympathetic activity, bringing the heart back to rest because it acts on the reduction of heart rate (vagal action)
The parameters we observed investigate the post-stress restoration trend in short-term recovery. In the subjects of the test, the hemodynamic factors are particularly altered and the autonomic nervous system activation is evident to help the body return to normal. In this situation, the graduated compression costume seems to play an important supporting role. The results of studies conducted at the Bologna Engineers' Laboratory labs indicate that wearing a compressed costume will result in an improvement of about 20 minutes on post-recovery recovery after an intense swimming performance.
Editor Aquarius Verona