This discussion was started in another thread-
was brought up.
I am by no means a Don Chu fan.
The site really lacked any scientific backing for the use of the product. - great marketing to make you think you need the product- you KNOW your training is missing this key piece of equipment
I thought the price was also high for the Xvest.
Here is some of the research preformed by Bosco on the subject:
Med Sci Sports Exerc 1986 Aug;18(4):415-9
The effect of extra-load conditioning on muscle performance in athletes.
Bosco C, Rusko H, Hirvonen J.
Fourteen sprinters were assigned to an experimental group (N = 7) and a control group (N = 7) in order to study the effects of 3 wk of extra-load conditioning. The extra-load conditioning was achieved by the athletes wearing special vests containing weights (7-8% body mass). The vests were used from morning to evening and during 3-5 training sessions/wk for 3 wk. No changes in the ordinary training regime were allowed, except the use of the vest by the experimental group. A jumping test battery and short running test on a treadmill were utilized to measure explosive power characteristics and the anaerobic performance of the subjects. While the control group showed no changes in any of the variables studied, the experimental subjects significantly improved their jumping heights in squat jumps with and without extra loads; their jumping heights in drop jumps and mechanical power output in 15 s of jumps. No changes in lactate levels or in running times to exhaustion were observed in response to the extra-load conditioning. The improvement of jumping performances could be due to a fast neurogenic adaptation to the new requirements.
More from Bosco:
Eur J Appl Physiol Occup Physiol 1984;53(2):149-54
The influence of extra load on the mechanical behavior of skeletal muscle.
Bosco C, Zanon S, Rusko H, Dal Monte A, Bellotti P, Latteri F, Candeloro N, Locatelli E, Azzaro E, Pozzo R, et al.
Eleven international jumpers and throwers engaged in year round training were divided into experimental (n = 6) and control (n = 5) groups. The experimental group was tested before and after a 3 weeks simulated hypergravity period, and again 4 weeks after the hypergravity period. The high gravity condition was created by wearing a vest weighing about 13% of the subjects body weight. The vest was worn from morning to evening including the training sessions, and only removed during sleep. The daily training of all subjects consisted of classical weight training and jumping drills. No changes in the ordinary training program were allowed in the experimental group, except for the use of the vest. Vertical jumps, drop jumps and a 15 s continuous jumping test were used to measure the explosive power characteristics of the subjects. After the hypergravity period the experimental subjects demonstrated significant (5-10%, P less than 0.05-0.01) improvements in most of the variables studied: however, 4 weeks after cessation of the high gravity period they tended to return towards the starting values. No changes were observed in the results of the control group. The improvement observed in the experimental subjects was explained as fast adaptation to the simulated high gravity field. It is suggested that adaptation had occurred both in neuromuscular functions and in metabolic processes.
Acta Physiol Scand 1985 Aug;124(4):507-13
Adaptive response of human skeletal muscle to simulated hypergravity condition.
Bosco C.
The mechanical behaviour of leg extensor muscles of five international-level athletes was evaluated during 13 months training period. Drop jumps, average mechanical power during 15 S continuous jump, and vertical jumps performed with and without extra weights were used to measure explosive power characteristics. The data recorded in vertical jumps was utilized for construction of force-velocity relationship (F-V curve). The athletes did not show improvement in any of the variables studied after 12 months of intensive systematic training programme. It was assumed that the subjects already had reached their upper limit of performance. However, after that the athletes underwent a simulated 3 weeks high-gravity period. The hypergravitational condition was created by wearing a special vest filled with extra loads (11% of BW). The vest was used from morning to evening. No changes in the ordinary training programme were allowed. After the simulated high-gravity conditioning period significant improvement in almost all the variables studied was observed (P less than 0.05-0.001). Vertical jump performance was enhanced from 44.3 to 54.9 cm. The F-V curve remained stable all year but after hypergravity period shifted markedly to the right. The drastic improvement was attributed to be caused by a fast adaptation to the new functional requirements (I.I g). Therefore, once the biological adaptation occurred the mechanical behaviour of the athlete’s leg extensor muscle was similar to that which could be experienced in a field at low gravity condition (0.9 g). Adaptive response to the hypergravity conditioning was speculated to occur mainly at neurogenic level and less in myogenic component.
Tom, I agree with you in the sense that when anyone claims they have the ONE ingredient missing in your training - there are no magic bullets. But it could be useful in the GPP and an interesting way to load without using a bar or dumbbells.
I have ordered one, am not paying for it, but expect it to be useful in certain situations. I will give an opinion when I have had a chance to experiment a bit. We won´t be using it with sprinters much, but in other sports.
IF anyone is interested in ordering one, do it over the phone and tell them that you read about it in testosterone magazine (t-mag web site, they featured it a while back), and you will get a discount. I am a little curious about transporting it. I am picking it up in Canada, and flying back to Europe. With all the security checks, I wonder what they will think when they see a vest with 40 cylindrical objects?
Anyone had security problems lately in airports who can give tips? I was thinking of checking my bags a day in advance, doing a show and tell with the stuff so that I don´t get stopped 30 min before my flight as a suspected terrorist.
Not to mention buying a filter or mask when flying to Canada. Is SARS really as a big scare as it looks to be on the news here in Europe?
Not that I am against weighted vests-
The problem I have is that “Plyometrics” is very misunderstood in the West.
As for the 10% rule- most coaches start at 10% additional resistance and hope the body adapts rather than find the appropriate resistance that does not disturb the biomechanics.
I’m off the soap box…