The purpose of this study was to measure and compare the total
energy expenditure of the four competitive swimming strokes.
Twenty-six swimmers of international level were submitted to
an incremental set of 200-m swims (5 swimmers at Breaststroke,
5 swimmers at Backstroke, 4 swimmers at Butterfly and 12
swimmers at Front Crawl). The starting velocity was approximately
0.3m· s–1 less than a swimmer’s best performance and
thereafter increased by 0.05m· s–1 after each swim until exhaustion.
Cardio-pulmonary and gas exchange parameters were
measured breath-by-breath (BxB) for each swim to analyze oxygen
consumption (V˙ O2) and other energetic parameters by portable
metabolic cart (K4b2, Cosmed, Rome, Italy). A respiratory
snorkel and valve system with low hydrodynamic resistance
was used to measure pulmonary ventilation and to collect
breathing air samples. Blood samples from the ear lobe were collected
before and after each swim to analyze blood lactate concentration
(YSI 1500 L, Yellow Springs, Ohio, USA). Total energy
expenditure (E˙ tot), was calculated for each 200-m stage.E˙ tot differed
significantly between the strokes at all selected velocities.
At the velocity of 1.0m· s–1 and of 1.2m· s–1 the E˙ tot was significantly
higher in Breaststroke than in Backstroke, in Breaststroke
than in Freestyle and in Butterfly than in Freestyle. At the velocity
of 1.4m· s–1, the E˙ tot was significantly higher in Breaststroke
than in Backstroke, in Backstroke than in Freestyle, in Breaststroke
than in Freestyle and in Butterfly than in Freestyle. At the
velocity of 1.6m· s–1, the E˙ tot was significantly higher in Breaststroke
and in Butterfly than in Freestyle. As a conclusion, E˙ tot of
well-trained competitive swimmers was measured over a large
range of velocities utilising a new BxB technique. Freestyle was
shown to be the most economic among the competitive swimming
strokes, followed by the Backstroke, the Butterfly and the
Breaststroke.
