from 17 top level athletes within 10 min of com-
pleting a 400-m race in a major competition.
Postrace blood lactate concentrations were
highest in the fastest athletes, as reflected in the
strong correlation between running speed and
lactate concentration for men (r=0.85) and
women (r=0.80).
A later study by Hirvonen and colleagues
(1992) measured the changes in the muscle con-
centration of ATP, PCr and lactate during a 400-
m sprint. A 400-m race was performed (time, 51.9
±0.7 s) and split times for every 100 m recorded.
On subsequent occasions, the six male runners
were required to run 100, 200 and 300 m at the
same speed as their 400-m split times. Biopsies
were taken from the vastus lateralis muscle
before and after each sprint and analysed for PCr
and lactate concentrations. After the first 100 m,
muscle PCr concentration fell from 15.8±1.7–8.3
±0.3 mmol · kg–1wet weight (Fig. 41.3), and by
the end of the race, PCr concentration had fallen
by 89% to 1.7±0.4 mmol · kg–1wet weight. The
average speed over the 400 m decreased after 200
m, even though PCr was not depleted and lactate
was not at maximum level at this point in the race
(Fig. 41.3). The rate of muscle lactate accumula-
tion for the first 100 m was about half that during
the two subsequent sections of the race (100–200
and 200–300 m), showing an increased contribu-
tion of anaerobic glycolysis to energy production
up to this point. The rate of ATP yield from gly-
colysis was maximal between 200 and 300 m, as
indicated by the highest rate of lactate accumula-
tion in muscle and blood during this point in the
race. Over the last 100 m, the rate of glycolysis
declined, resulting in a dramatic decrease in
running speed.Metabolic responses to sprinting
in the laboratory
The development of specific and sensitive labo-
ratory methods to study sprinting provides an
opportunity to examine this form of activity in
a controlled way (Bar-Or 1978; Lakomy 1986,
1987; Falk et al. 1996).
Sprinting has been studied in the laboratory
using a non-motorized treadmill (Lakomy 1987).
In the study by Lakomy (1987), performance and
metabolic responses during two 30-s sprints
were compared. Seven male national level
sprinters, whose specialist events ranged from
100 to 400 m, performed one sprint on a non-
motorized treadmill, and a second sprint on a
running track. Although peak speed and mean
speed were slower on the treadmill than on the
track, there was no difference in the number of
strides taken. In addition, similar physiological
and metabolic responses to both runs were
observed, demonstrating that the treadmill
sprint was a useful tool for the analysis of
the physiological demands of sprint running
in the laboratory. Postexercise blood lactate con-
centrations were 16.8 vs. 15.2 mmol · l–1for tread-
mill and track runs, respectively. Heart rate
averaged 198 beats · min–1in both 30-s sprints,
and postrace blood glucose concentration was
6.4±1.1 mmol · l–1 after the treadmill run, and
6.2±1.0 mmol · l–1 after the track run (H.K.A.
Lakomy, unpublished observations).
Cheethamet al. (1986) examined performance
during, and the changes in muscle metabolites
following, a 30-s sprint on a non-motorized
treadmill. Peak power output for eight femalesprinting 537
Fig. 41.3Muscle phosphocreatine () and lactate
concentrations () at various speeds during a
simulated 400-m track sprint (Hirvonen et al. 1992).
806040200806040200
0 100 200 300 400 500
Distance (m)Phosphocreatine (mmol.kg–1dm)Muscle lactate (mmol.kg–1dm)8.06 m.s–18.3 m.s–1 7.64 m.s–17.01 m.s–1