Maximal oxygen consumption is consistently lower when measured during swimming than during running or bicycling. A number of factors could contribute to this difference, including size of active muscle mass, body position, heat exchange mechanisms, breathing patterns and adjustments to water immersion.
In this study, the effects of water immersion on submaximal exercise were isolated by having subjects perform identical work in air and water. The exercise consisted of rowing on a rowing machine, with rate of movement controlled so that the subjects always worked at the same relative workload and oxygen consumption. To compare the physiological responses to exercise in air and water, measurements and calculations were made of oxygen consumption, carbon dioxide production, respiratory exchange ratio, minute ventilation, respiratory rate, tidal volume, recovery heart rate and lactic acid accumulation.
The experiment was conducted in three phases. In Phase I, the subjects' maximum oxygen consumptions were measured with a standard bicycle ergometer test. Phase II determined the rate of work on the rowing machine required for each subject to attain 70 to 80% of his maximum oxygen consumption. Water resistance necessitated a slower work rate in the water than in the air. Phase III provided the data for comparing physiological responses to exercise in air and water. In this final phase, each subject performed one test in air and one in water, with nearly identical oxygen consumptions in both tests.
Responses to exercise in air and water were quite similar. There was no significant difference between any of the measurements made during the exercise, including oxygen consumption, carbon dioxide production, respiratory exchange ratio, minute ventilation, respiratory rate and tidal volume. Recovery heart rates were similar. Lactic acid concentration, measured during the fifth minute of recovery, was slightly, but significantly, greater following the water tests.
The oxygen cost of each pull on the rowing machine was calculated by dividing the oxygen consumption per minute by the number of pulls per minute. Rowing in the water required 50 to 60% more oxygen than rowing in air. This may be a good estimate of the additional energy expenditure required for underwater work.
It is concluded that water immersion per se has little effect on the response to submaximal exercise. The reduction in maximal oxygen consumption during swimming compared to running or bicycling must be due to differences other than immersion, such as size of active muscle mass, body position, breathing patterns or heat loss mechanisms.
Level of Degree
UNM Biology Department
First Committee Member (Chair)
Marvin LeRoy Riedesel
Second Committee Member
Earl Whitfield Bourne
Third Committee Member
Eric Craig Toolson
Fourth Committee Member
Carlberg, Karen Ann. "Cardiorespiratory Responses To Submaximal Exercise In Water." (1976). https://digitalrepository.unm.edu/biol_etds/392