Training Breathing Muscles Improves Swimming Muscles' Performance

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Training Breathing Muscles Improves Swimming Muscles' Performance

http://www.sciencedaily.com/releases/2007/01/070118094155.htm

Swimmers and scuba divers can improve their swimming endurance and

breathing capacity through targeted training of the respiratory

muscles, researchers at the University at Buffalo have shown.

In this pioneering work, subjects who followed a resistance-

breathing training protocol (breathing load) improved their

respiratory muscle strength and their snorkel swimming time by 33

percent and underwater scuba swimming time by 66 percent, compared

to their baseline values. Participants randomized to a similar

protocol requiring high respiratory flow rates (endurance) improved

their respiratory endurance and surface and underwater swimming

times by 38 percent and 26 percent, respectively.

The group randomized to a placebo training program, conducted with

the same equipment and protocol, showed no significant improvement

in respiratory or swimming performance.

Results of the study, conducted in UB's Center for Research and

Education in Special Environments (CRESE) appeared in the December

online issue of the European Journal of Applied Physiology and will

appear in printnext month.

" Specific respiratory muscle training could allow divers in the

military, civilian rescue services, commercial enterprises and sport

to perform better underwater, " said Claes E.G. Lundgren, M.D.,

Ph.D., professor of physiology and biophysics in the UB School of

Medicine and Biomedical Sciences and the study's senior author.

R. Pendergast, Ed.D., professor of physiology and biophysics,

adjunct professor of mechanical and aerospace engineering and CRESE

director, along with his research group, were instrumental in the

research.

Lundgren said that training the breathing muscles to improve the

performance of swimming muscles seems counter-intuitive, but is

logical physiologically.

" Typically, we think it's the muscles that move the body that are

fatigued when we tire, " he noted. " However, the increased work load

of the breathing muscles is very important, particularly underwater

during prolonged or high intensity exercise such as swimming.

" As shown by other studies, when breathing muscles become fatigued,

the body switches to survival mode and " steals " blood flow and

oxygen away from the locomotor muscles and redirects it to the

respiratory muscles to enable the diver to continue breathing.

Deprived of oxygen and fuel, the locomotor muscles become fatigued.

" Increasing the strength and endurance of the respiratory muscles

prevents their fatigue during sustained exercise, enabling divers

and swimmers to sustain their effort longer without tiring, "

Lundgren said.

The study involved 30 experienced male swimmers in their 20s. To

insure the safety of participants and establish uniform fitness, all

enrollees took four weeks of swim-fin and scuba-diving training

before the start of the study.

Participants also underwent baseline tests to determine pulmonary

strength (maximal pressures they could generate), pulmonary

endurance (time that a high ventilation could be sustained), VO2max

(the maximal volume of oxygen they could consume per minute to

produce energy for exercise), and length of time they could swim at

a moderately high speed.

The men then were randomized to one of three training protocols:

RRMT-resistance respiratory muscle training; ERMT-endurance

respiratory muscle training; or PRMT-placebo respiratory muscle

training. The protocols were followed for 30 minutes per day, five

days a week, for four weeks.

Swimmers assigned to the RRMT inhaled and exhaled against a valve

that had a set opening pressure and imposed a continuous resistance

using specialized breathing valves and a computer tracking system

developed in CRESE.

Swimmers in the ERMT protocol, using the same equipment, increased

their breathing rate and tidal volume (total ventilation)

progressively each week, while a re-breathing bag insured that the

amount of carbon dioxide in the blood was held constant, in spite of

the hyperventilation during the training.

During PRMT, subjects performed a series of 10-second breath-holds,

with 90-second rest periods between breath-holds, using the same

equipment as in RRMT and ERMT. The rest periods were shortened by 10

seconds each week, ending with a 60-second rest between breath-holds

during the fourth week.

All subjects participated in a twice-a-week, identical fin-swimming

maintenance program during the four weeks of RMT training to insure

that they maintained, but didn't increase, their fitness levels

during the study's training protocol.

At the end of the four weeks, study participants repeated the

baseline tests.

" Results showed that the RRMT and ERMT protocols used in this study

significantly extended swimming endurance through an improvement in

respiratory muscle performance, " said Lundgren.

" These data are in agreement with previous studies in cyclists,

rowers and runners. They suggest that athletes in most sports could

improve their performance by undergoing respiratory muscle training.

It is also clear that the greater the stress on the respiratory

system, the larger the improvement in performance. "

Lundgren noted that this type of training also may be useful for

patients who suffer from respiratory stress.

Juli A. Wylegala, Ph.D., UB clinical assistant professor of

rehabilitation sciences, is first author. Pendergast, Luc E.

Gosselin, Ph.D., associate professor of exercise and nutrition

sciences, and Dan E. Warkander, Ph.D., research assistant professor

of physiology and biophysics, are additional authors.

The research was supported by a grant from the Naval Sea Costal

Systems (Navy Experimental Diving Unit).

The University at Buffalo is a premier research-intensive public

university, the largest and most comprehensive campus in the State

University of New York. The School of Medicine and Biomedical

Sciences is one of five schools that constitute UB's Academic Health

Center.

Note: This story has been adapted from a news release issued by

University at Buffalo.