The 10-20-30 training concept improves performance and health profile in moderately trained runners

Abstract

The effect of an alteration from regular endurance to interval (10-20-30) training on the health profile, muscular adaptations, maximum oxygen uptake (Vo(2max)), and performance of runners was examined. Eighteen moderately trained individuals (6 females and 12 males; Vo(2max): 52.2 ± 1.5 ml·kg(-1)·min(-1)) (means ± SE) were divided into a high-intensity training (10-20-30; 3 women and 7 men) and a control (CON; 3 women and 5 men) group. For a 7-wk intervention period the 10-20-30 replaced all training sessions with 10-20-30 training consisting of low-, moderate-, and high-speed running (<30%, <60%, and >90% of maximal intensity) for 30, 20, and 10 s, respectively, in three or four 5-min intervals interspersed by 2 min of recovery, reducing training volume by 54% (14.0 ± 0.9 vs. 30.4 ± 2.3 km/wk) while CON continued the normal training. After the intervention period Vo(2max) in 10-20-30 was 4% higher, and performance in a 1,500-m and a 5-km run improved (P < 0.05) by 21 and 48 s, respectively. In 10-20-30, systolic blood pressure was reduced (P < 0.05) by 5 ± 2 mmHg, and total and low-density lipoprotein (LDL) cholesterol was lowered (P < 0.05) by 0.5 ± 0.2 and 0.4 ± 0.1 mmol/l, respectively. No alterations were observed in CON. Muscle membrane proteins and enzyme activity did not change in either of the groups. The present study shows that interval training with short 10-s near-maximal bouts can improve performance and Vo(2max) despite a ∼50% reduction in training volume. In addition, the 10-20-30 training regime lowers resting systolic blood pressure and blood cholesterol, suggesting a beneficial effect on the health profile of already trained individuals.

Full text

The 10-20-30 training concept improves performance and health
profile in moderately trained runners
T. P. Gunnarsson and J. Bangsbo
Department of Exercise and Sport Sciences, Section of Integrated Physiology, University of Copenhagen,
Copenhagen, Denmark
Submitted 15 March 2012; accepted in final form 2 May 2012
Gunnarsson TP, Bangsbo J. The 10-20-30 training concept im-
proves performance and health profile in moderately trained runners.
J Appl Physiol 113: 16 –24, 2012. First published May 3, 2012;
doi:10.1152/japplphysiol.00334.2012.—The effect of an alteration
from regular endurance to interval (10-20-30) training on the health
profile, muscular adaptations, maximum oxygen uptake (V
˙O
2max
), and
performance of runners was examined. Eighteen moderately trained
individuals (6 females and 12 males; V
˙O
2max
: 52.2 ⫾1.5
ml·kg
⫺1
·min
⫺1
) (means ⫾SE) were divided into a high-intensity
training (10-20-30; 3 women and 7 men) and a control (CON; 3
women and 5 men) group. For a 7-wk intervention period the
10-20-30 replaced all training sessions with 10-20-30 training con-
sisting of low-, moderate-, and high-speed running (⬍30%, ⬍60%,
and ⬎90% of maximal intensity) for 30, 20, and 10 s, respectively, in
three or four 5-min intervals interspersed by 2 min of recovery,
reducing training volume by 54% (14.0 ⫾0.9 vs. 30.4 ⫾2.3 km/wk)
while CON continued the normal training. After the intervention
period V
˙O
2max
in 10-20-30 was 4% higher, and performance in a
1,500-m and a 5-km run improved (P⬍0.05) by 21 and 48 s,
respectively. In 10-20-30, systolic blood pressure was reduced (P⬍
0.05) by 5 ⫾2 mmHg, and total and low-density lipoprotein (LDL)
cholesterol was lowered (P⬍0.05) by 0.5 ⫾0.2 and 0.4 ⫾0.1
mmol/l, respectively. No alterations were observed in CON. Muscle
membrane proteins and enzyme activity did not change in either of the
groups. The present study shows that interval training with short 10-s
near-maximal bouts can improve performance and V
˙O
2max
despite a
⬃50% reduction in training volume. In addition, the 10-20-30 training
regime lowers resting systolic blood pressure and blood cholesterol,
suggesting a beneficial effect on the health profile of already trained
individuals.
high-intensity training; maximal oxygen uptake; blood pressure;
plasma lipid profile; muscular adaptations
IT IS WELL ESTABLISHED that untrained individuals have major
muscle adaptations and increase in maximum oxygen uptake
(V
˙O
2max
) and performance after a period of endurance training
(10, 15, 24, 29, 31, 33, 35, 38, 39). On the other hand, for
already trained individuals it appears necessary to intensify the
training and include exercise bouts at an intensity close to or
slightly above the intensity corresponding to V
˙O
2max
, to obtain
improvements in V
˙O
2max
and performance (11, 18, 25, 45, 48).
Training at maximal and near-maximal exercise intensities
seems also to be effective in creating muscular adaptations,
such as increases in the activity of oxidative enzymes, and
expression of Na
⫹
-K
⫹
pump subunits and lactate and H
⫹
transporters, and endurance performance improvement in un-
trained individuals (5, 8, 33). Even well-trained individuals
improved short-term performance after having carried out
training with 30-s maximal running bouts for a 4-wk period,
despite a 64% reduction in training volume (20). When com-
bining training with 30-s sprints and, on separate days, aerobic
high-intensity training consisting of 4 ⫻4 min with a heat rate
of 90 –100% of maximal heart rate (HRmax), long-term per-
formance was also improved although the training volume was
lowered by 25% (4). In these studies the improvements in
performance were associated with a better running economy
and an increased amount of Na
⫹
-K
⫹
pump subunits ␣1 and ␣2.
In accordance, running economy has been shown to be better
after a period of interval (6, 14, 18, 43), plyometric (36, 42, 44,
46), and strength (32) training. Furthermore, studies on well-
trained subjects, who either performed strength training (30) or
increased their training intensity (13, 29), have reported in-
creased Na
⫹
-K
⫹
pump concentrations as determined by the
[
3
H]ouabain-binding technique. In contrast, Aughey et al. (3)
did not find changes in the abundance of any of the Na
⫹
-K
⫹
pump ␣isoforms when already trained subjects performed a
period of intensified training. The lack of effect in the latter
study may have been a result of the exercise intensity being
below the one corresponding to V
˙O
2max
. Nevertheless, the
changes in the expression of Na
⫹
-K
⫹
pump may affect per-
formance, since Nielsen et al. (34) observed that elevated
levels of Na
⫹
-K
⫹
pump ␣
1
- and ␣
2
-subunits after 8 wk of
knee-extensor training at supramaximal exercise intensities
were associated with a reduced muscle interstitial K
⫹
concen-
tration during exercise as well as better performance during
intense exercise (34). In addition, other muscle ion transport
proteins, such as the Na
⫹
/H
⫹
exchanger isoform 1 (NHE1) and
monocarboxylate transporters 1 and 4 (MCT1 and MCT4),
facilitating lactate and H
⫹
exchange across the muscle mem-
brane, have been shown to be changed with intense training
and may have contributed to the improved short-term perfor-
mance (7, 20 –22, 33). It is, however, unclear whether training
using 10-s near-maximal sprints has the same effect as 30-s
intervals and whether combining aerobic and anaerobic train-
ing (19), i.e., maintaining a relatively high HR during training,
can affect V
˙O
2max
and performance and lead to adaptations in
the trained muscles. Such type of training is performed in the
10-20-30 concept where the participant in a 5-min period is
alternating between low speed for 30 s, moderate speed for 20
s, and high-speed running (⬎90% of maximal speed) for 10 s.
It is clear that physical activity has a significant impact on
the health profile in untrained individuals. Thus a typical
response for a sedentary individuals to a period of endurance
training is a reduction in blood pressure (BP) and lowering of
the blood cholesterol levels (37). However, less is known about
the effect of intense intermittent training. In a recent study
Nybo et al. (35) found in untrained individuals a lowering in
systolic BP after 12 wk of interval training (40 min/wk at an
Address for reprint requests and other correspondence: J. Bangsbo, August
Krogh Bldg., Section of Integrated Physiology, Universitetsparken 13, DK-
2100 Copenhagen Ø, Denmark (e-mail: jbangsbo@ifi.ku.dk).
J Appl Physiol 113: 16 –24, 2012.
First published May 3, 2012; doi:10.1152/japplphysiol.00334.2012.
8750-7587/12 Copyright ©2012 the American Physiological Society http://www.jappl.org16

intensity corresponding to 95% of HRmax), but no change in
diastolic BP and resting HR was observed. In contrast all
variables were lowered in a group performing endurance train-
ing for 150 min at 80% of HRmax per week. The blood lipid
profile, expressed as a ratio between total- and high-density
lipoprotein (HDL) cholesterol, did not change in the interval
group whereas there was a 15% reduction in the endurance
training group. The difference may be related to the shorter
training duration in the interval group. In a study by Kraus et
al. (23), 111 sedentary overweight men and women with mild
to moderate dyslipidemia were randomly assigned to either a
control group or training group for 8 mo. In two of the training
groups (moderate intensity) participants either jogged for 19
(low amount) or 32 (high amount) km/wk at 65– 80% of
V
˙O
2max
, and in a third group participants walked for 19 km/wk
at 40 –55% of V
˙O
2max
(low amount; low intensity). Only the high
amount, moderate-intensity training group lowered the concentra-
tion of low-density lipoprotein (LDL) and raised the concentration
of HDL, suggesting that moderate-, but not low-, intensity training
can have beneficial effects on the lipoprotein profile. In a recent
study Williams (49) showed that exercise intensity was inversely
associated with the prevalence of elevated BP and blood choles-
terols independent of cardiorespiratory fitness and amount of
exercise, suggesting that the higher the exercise intensity the
greater the health benefits. However, it is unclear whether training
at near-maximal intensity can affect the health profile of already
trained subjects.
Thus the aim of the present study was to test the hypothesis
that 7 wk of 10-20-30 training can improve endurance perfor-
mance, cardiovascular fitness, and health profile as well as
induce muscular adaptations in already trained subjects.
METHODS
Subjects
Eighteen moderately trained subjects (12 men and 6 women) with
an age, height, weight, and V
˙O
2max
of 33.8 ⫾1.6 yr, 178.8 ⫾2.1 cm,
75.2 ⫾3.5 kg, and 52.2 ⫾1.5 ml·kg
⫺1
·min
⫺1
, respectively, partici-
pated in the study. The subjects were divided into a group training after
the 10-20-30 concept (10-20-30; n⫽10) (see below) and a control group
(CON; n⫽8). Groups were matched by V
˙O
2max
(52.2 ⫾2.4 and 52.3 ⫾
2.0 ml·kg
⫺1
·min
⫺1
, respectively) and performance in a 5-km run (23.03
⫾1.06 and 23.03 ⫾1.25 min, respectively). Furthermore, groups did not
differ in age, weight, and body mass index, and there were 3 female
runners in each group. All participants were fully informed of experi-
mental procedures and any discomforts associated with participating in
the study before signing a written informed consent. This study con-
formed to the code of Ethics of the World Medical Association (Decla-
ration of Helsinki) and the Title 45, U.S. Code of Federal Regulations,
Part 46, Protection of Human Subjects, Revised November 13, 2001, and
was approved by the Ethics Committee of Copenhagen and Frederiksberg
communities.
Experimental Design
In a 7-wk intervention period the 10-20-30 training group trained
by the 10-20-30 training concept replacing all regular training ses-
sions with three weekly 10-20-30 training sessions and CON contin-
ued with their regular endurance training (see Training). Four weeks
prior to as well as before and after the intervention period the subjects
underwent a series of tests: 1) a treadmill test to determine V
˙O
2max
and
maximal aerobic speed (MAS), 2) a 1,500-m run, and 3) a 5-km run
(see Testing). In addition, on a separate day before and after the
intervention period, subjects reported to the laboratory after an over-
night fast and had a blood sample taken and BP measured. Further-
more, before, during (week 4), and after the intervention period, a
biopsy from the vastus lateralis muscle was taken.
Training
Prior to the intervention period subjects had two to four weekly training
sessions with a training volume of 27.3 ⫾2.8 km lasting 137.5 ⫾13.4
min with no difference (P⬎0.05) between 10-20-30 and CON with
regard to weekly training volume (30.4 ⫾4.3 and 24.1 ⫾3.6 km) or
weekly duration of training (155.9 ⫾19.9 and 119.2 ⫾16.4 min),
respectively.
The 10-20-30 training concept consisted of a standardized ⬃1.2 km
warm-up at a low intensity followed by 3– 4 ⫻5 min running
interspersed by 2 min of rest. Each 5-min running period consisted of
five consecutive 1 min intervals divided into 30, 20, and 10 s at an
intensity corresponding to ⬍30%, ⬍60%, and 90 –100% of maximal
intensity (determined from 5-Hz GPS data), respectively. During the
intervention period 10-20-30 had 3 weekly training sessions with a
volume of 14.0 ⫾0.6 km/wk (including warm-up). In the first 4 wk,
10-20-30 conducted three 5-min intervals and, in the remaining 3 wk,
four 5-min intervals per training session. The total high-speed running
amounted to 8.6 ⫾0.5 min/wk during the intervention period. In CON
the weekly training volume (24.8 ⫾3.4 and 24.1 ⫾3.6 km) and time
spent (132.4 ⫾16.6 and 119.2 ⫾16.4 min) during the intervention
period was the same as before the intervention period.
Testing
Prior to all testing subjects refrained from severe physical activity
for at least 48 h and all testing was at least 3 h after ingestion of a
meal. The subjects performed 1) a 1,500-m run, 2) a 5-km run, and
3) an incremental test to exhaustion on a motorized treadmill (see
below). The subjects were familiarized to all testing protocols on at
least one separate occasion, and all tests were preceded by a thorough
and standardized 15-min warm-up program. Calculation of the indi-
vidual running speed (60% and 75% of MAS) was based on a V
˙O
2max
test performed within the last 2 wk prior to the study.
1,500-m run. The 1,500-m test consisted of 3.75 laps on a 400-m
synthetic track. Subjects were wearing a HR monitor (Polar team
system, Polar, Electro Oy) but did not wear watches during the
1,500-m and thus were not aware of running time. The running time
for the first 400 m (1 lap) was given. Time to complete the 1,500 m
was used as the test result.
5-km run. The 5-km test consisted of 12.5 laps on a 400-m
synthetic track. Subjects were wearing a HR monitor (Polar team
system, Polar, Electro Oy, Kempele, Finland) but did not wear
watches during the 5-km run and thus were not aware of running time.
The time for the first 1,000 m (2.5 laps) was given. The time to
complete the 5-km was used as the test result.
Incremental test to exhaustion. The participants reported to the
laboratory ⬃1 h before the V
˙O
2max
test. After 20 min of rest in the
supine position, a muscle biopsy from the vastus lateralis muscle was
collected through an incision made in the skin under local anesthesia
(20 mg/ml lidocaine without norepinephrine) and a catheter (18
gauge, 32 mm) was placed in an antecubital vein. In addition, a HR
monitor (Polar team system, Polar, Electro Oy) was placed on the
subject and HR was recorded in 5-s intervals to determine peak HR.
The treadmill test protocol consisted of 2 ⫻6 min running at 60 and
75% of MAS interspersed with 2 min of rest. After the two submaxi-
mal running bouts an incremental test to exhaustion was performed
starting with 3 min at 75% of MAS. Hereafter running speed was
increased by 1 km/h every minute until volitional fatigue. V
˙O
2max
was
measured throughout the protocol with a breath-by-breath gas analyz-
ing system (Oxycon Pro, Viasys Healthcare, Hoechberg, Germany)
that was calibrated before each test. V
˙O
2max
was determined as the
highest value achieved during a 30-s period. Criteria used for achieve-
ment of V
˙O
2max
were a plateau in V
˙O
2
despite an increased running
1710-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

speed and a respiratory exchange ratio above 1.15. Blood samples
during the test were collected in heparinized 2-ml syringes before and
immediately after each of the running bouts and at exhaustion as well
as 1, 3, and 5 min in recovery of the incremental test to exhaustion.
Immediately after being taken, the blood sample was stored on ice and
analyzed for blood lactate using an ABL 800 Flex (Radiometer,
Copenhagen, Denmark).
Health Profile
Subjects reported to the laboratory between 6 and 10 A.M. on a
separate day after an overnight fasting. After resting for at least 15
min in the supine position, BP was measured six consecutive times by
an automatic upper arm BP monitor (M7, OMRON, Vernon Hills, IL)
and fasting blood and plasma lipoproteins, hemoglobin, iron, glucose,
myoglobin, creatine kinase, cortisol, insulin, and triglycerides were
determined under standardized conditions.
Muscle Analysis
The muscle sample was immediately frozen in liquid N
2
and stored
at ⫺80°C. The frozen muscle tissue samples were weighed before and
after freeze drying to determine the water content. After freeze drying,
connective tissue, visible fat, and blood were carefully dissected away
in the samples. Dissecting was done under a stereomicroscope with an
ambient temperature of ⬃18°C and a relative humidity below 30%.
Muscle ion transport proteins. A part of the muscle sample taken
at rest (⬃4 –5 mg dry wt) was homogenized on ice in a fresh batch of
buffer (10% glycerol, 20 mM Na-pyrophosphate, 150 mM NaCl, 50
mM HEPES, 1% Nonidet P-40, 20 mM ␤-glycerophosphate, 10 mM
NaF, 2 mM PMSF, 1 mM each of EDTA and EGTA and 10 ␮g/ml
each aprotinin and leupeptin and 3 mM benzamidine) with a Polytron
3100 (Kinematica) for not more than 30 s. After rotation end over end
for ⬃1 h, the samples were centrifuged for 30 min at 17,500 gat 4°C,
and lysates were collected as the supernatant. Protein concentrations
were determined in the lysates using BSA standards (Pierce Re-
agents). The lysates were diluted to appropriate protein concentrations
ina6⫻sample buffer (0.5 M Tris-base, DTT, SDS, glycerol, and
bromphenol blue), and equal amount of total protein (5–15 ␮gin
accordance with the antibody optimization) were loaded for each
sample in different wells on 10% precasted Tris·HCl gels (Bio-Rad
Laboratories, Hercules, CA). For comparisons, samples from the same
subject were always loaded on the same gel. The gel electrophoresis
ran for ⬃80 –100 min with 55 mA and a maximum of 150 V per gel.
Afterward proteins were blotted to a polyvinylidene difluoride mem-
brane using 70 mA and a maximum of 25 V per gel in ⬃2h.The
membranes were incubated overnight with 20 –30 ml of primary
antibody diluted in either 2% nonfat milk [monoclonal Na
⫹
-K
⫹
pump
␣1-subunit (⬃100 kDa), 1:500 dilution (C464.6, no. 05–369, Milli-
pore); polyclonal ␣2-subunit (⬃100 kDa), 1:500 dilution (no. 07–
674, Millipore); and monoclonal ␤1-subunit (⬃50 kDa), 1:1,000
dilution (MA3–930, Affinity BioReagents)] or 3% BSA [monoclonal
NHE1 (⬃100 kDa), 1:500 dilution; polyclonal MCT1 (⬃43 kDa),
1:1,000 dilution; and polyclonal MCT4 (⬃43 kDa), 1:1,000 dilution
(MAB3140, AB3538P, and AB3316P, Millipore)]. After being
washed briefly in a Tris-buffered saline-Tween, membranes were in-
cubated with secondary antibody for ⬃1 h at room temperature. The
secondary horseradish peroxidase-conjugated antibodies used were
diluted 1:5,000 in 2% nonfat milk or 3% BSA depending on the
primary antibody (P-0447, P-0448, and P-0449, DakoCytomation).
The membrane staining was visualized by incubation with a chemi-
luminescent horseradish peroxidase substrate (Millipore) immediately
before the image was digitalized on a Chemi Doc MP (Bio-Rad
Laboratories). Net band intensities were quantified using Image Lab
(Image Lab v. 4.0, Bio-Rad Laboratories).
Data treatment. Double determinations were made for the muscle
samples, i.e., the biopsies were divided and kept in two parts before
freeze drying, resulting in two results for the same time point. The
mean signal intensity of the two samples was used as the result for the
individual time point. The intensity of the individual time points were
divided with the mean intensity of the pre values within the group, to
show the variation in the pre-biopsies.
Muscle enzymes. A part of the muscle sample (⬃2mgofdry
weight) was homogenized (1:400) in a 0.3 M phosphate BSA buffer
adjusted to pH 7.7 and phosphofructokinase (PFK), hydroxyacyl-CoA
dehydrogenase (HAD), and citrate synthase (CS) muscle enzyme
activity was determined fluorometrically as described by Lowry and
Passonneau. (27).
Statistics
Student’s unpaired t-tests were used before the intervention period
to compare subject characteristics (V
˙O
2max
, 5-km performance, age,
weight, and body mass index) as well as before and during the
intervention to compare group differences in training volume and
time. Changes in performance (5 km and 1,500 m), BP, resting HR,
pulmonary V
˙O
2
, fasting blood, and plasma samples (total cholesterol,
LDL- and HDL-lipoproteins, hemoglobin, iron, glucose, myoglobin,
creatine kinase, cortisol, insulin, and triglycerides) and enzyme activ-
ities were evaluated using a two-way ANOVA for repeated measures,
Fig. 1. Average heart rate during a representative training session for the
10-20-30 (dashed line) and control (CON; solid line) group during the
intervention period (A) and time spent in various heart rate zones during a
training session in the 10-20-30 (filled bars) and CON (open bars) group (B).
HRmax, maximal heart rate. See Training for description of 10-20-30 group.
18 10-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

with time as one factor and group as the other factor. When a
significant interaction was detected, data were subsequently analyzed
using a Student-Newman-Keuls post hoc test. Changes in blood
lactate during treadmill running before and after the intervention were
evaluated using a two-way ANOVA for repeated measures with
sample time as one factor and time (pre vs. post) as the other factor
within each group. Group differences in blood lactate response within
pre and post were evaluated using a two-way ANOVA with group as
one factor and sample time as the other factor. Changes in muscle
membrane transport proteins were evaluated using a one-way
ANOVA for repeated measures with time (before and after 4 and 7
wk) as the factor. A significance level of P⬍0.05 was chosen. Data
are presented as means ⫾standard error of the mean (SE) unless
stated otherwise.
RESULTS
HR Response to Training
Average and peak HR for 10-20-30 and CON were 85 ⫾1
vs. 82 ⫾2 and 96 ⫾1 vs. 87 ⫾2% of HRmax, respectively.
The largest difference in the HR response to training in
10-20-30 and CON was time spent above 90% of HRmax,
which amounted to 11.1 and 0 min corresponding to 43 and 0%
of weekly training time, respectively (Fig. 1).
Performance
In 10-20-30, performance improved (P⬍0.01) by 6% in the
1,500-m run (5.79 ⫾0.22 vs. 6.16 ⫾0.29 min) and 4% in the
5-km run (22.26 ⫾0.90 vs. 23.07 ⫾1.07 min) during the 7-wk
intervention period whereas performance was not changed in
CON (Fig. 2).
Pulmonary V
˙O
2
In 10-20-30 V
˙O
2max
was 4% higher (P⬍0.05) after the
intervention period (53.8 ⫾2.3 vs. 51.6 ⫾1.9 ml·kg
⫺1
·min
⫺1
),
whereas no change was observed in CON (Table 1). V
˙O
2
at
running speeds of 9.9 and 12.4 km/h before and after the
intervention period was not different in either of the groups
(Table 1).
Fasting Blood and Plasma Values
After the intervention period total cholesterol (4.3 ⫾0.3 vs.
4.8 ⫾0.4 mmol/l) and LDL cholesterol (2.7 ⫾0.3 vs. 2.3 ⫾
0.3 mmol/l) was lower (P⬍0.05) in 10-20-30, whereas no
changes were observed in CON (Fig. 3). No changes were
found in blood hemoglobin and plasma iron, glucose, myoglo-
bin, creatine kinase, cortisol, insulin, and triglycerides during
the intervention period in either of the groups (Table 2)
Resting BP and HR
In 10-20-30, systolic BP at rest was lower (P⬍0.05) after
the intervention period (122 ⫾3 vs. 127 ⫾4 mmHg), whereas
no change was observed in CON (Fig. 4). Diastolic BP was the
same before and after the intervention period in both 10-20-30
(76 ⫾3 vs. 75 ⫾3 mmHg) and CON (67 ⫾4 vs. 65 ⫾3
mmHg). Also resting HR was unaltered in 10-20-30 (55 ⫾3
vs. 53 ⫾3 beats/min) and CON (52 ⫾2 vs. 49 ⫾3 beats/min).
Muscular Adaptations
The Na
⫹
-K
⫹
pump subunits ␣1, ␣2, and ␤1 as well as
NHE1, MCT1, and MCT4 were not changed during the inter-
vention period in either of the groups (Fig. 5). Likewise, no
changes were observed in the CS, HAD, or PFK activity during
the intervention period (Table 3).
Fig. 2. Performance during a 5-km (A) and 1,500-m (B) before (Pre) and after
(Post) the 7-wk intervention period for the 10-20-30 and control (CON) group.
*Different (P⬍0.001) from Pre.
Table 1. V
˙O
2max
and V
˙O
2
during two submaximal running
bouts before (Pre) and after (Post) the 7-wk intervention
period for the 10-20-30 and the control group
10-20-30 CON
Pre Post Pre Post
V
˙O
2max
l/min 3.98 ⫾0.29 4.16 ⫾0.31* 3.84 ⫾0.22 3.91 ⫾0.23
ml 䡠kg
⫺1
䡠min
⫺1
51.6 ⫾1.9 53.8 ⫾2.3† 52.3 ⫾1.6 53.5 ⫾1.6
V
˙O
2
,ml䡠kg
⫺1
䡠km
⫺1
9.9 km/h 214 ⫾7 214 ⫾5 214 ⫾8 213 ⫾7
12.4 km/h 210 ⫾5 213 ⫾4 206 ⫾7 210 ⫾6
Values are means ⫾SE. V
˙O
2
, oxygen consumption; V
˙O
2max
, maximal
oxygen consumption; CON, control. See Training for description of 10-20-30
protocol. *Different (P⬍0.05) from Pre. †Different (P⬍0.01) from Pre.
1910-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

Blood Lactate Response to Treadmill Running
Before and after the intervention period, blood lactate at rest,
after submaximal running, and after the exhaustive running
was the same for both 10-20-30 and CON (Table 4). Likewise,
no group differences within pre and post were observed.
DISCUSSION
The major findings of the present study were that after 7 wk
of 10-20-30 training, with a ⬃50% reduction in training
volume, V
˙O
2max
was elevated by 4% and performance in a
1,500-m and a 5-km run improved by 21 and 48 s, respectively.
Furthermore, the 10-20-30 training led to a marked reduction
in systolic BP as well as a lowering of total cholesterol and
LDL-cholesterol.
The 7-wk period with 10-20-30 training led to an improve-
ment in the 1,500-m and 5-km run of 6% and 4%, respectively,
despite a 54% reduction in training volume. The major differ-
ence between the 10-20-30 training and the normal training
was the speed during the 10-s intervals (⬎20 km/h), being
much higher than the pace before the intervention period
(10-14 km/h), which was similar to the speed during the 20-s
and higher than the 30-s exercise periods in the 10-20-30
Fig. 3. Total cholesterol (A), low-density lipoprotein (LDL; B), and high-density
lipoprotein (HDL; C) before (Pre) and after (Post) the 7-wk intervention period for
the 10-20-30 and control (CON) group. *Different (P⬍0.01) from Pre.
Table 2. Blood hemoglobin and plasma iron, glucose,
myoglobin, creatine kinase, cortisol, insulin, and
triglycerides after overnight fasting before (Pre) and after
(Post) the 7-wk intervention period for the 10-20-30 and the
control group
10-20-30 CON
Pre Post Pre Post
Hemoglobin, mmol/l 9.0 ⫾0.1 8.9 ⫾0.2 9.0 ⫾0.3 9.0 ⫾0.3
Iron, ␮mol/l 19.7 ⫾2.1 20.9 ⫾3.0 21.7 ⫾1.8 21.3 ⫾2.2
Glucose, mmol/l 5.1 ⫾0.3 5.1 ⫾0.2 4.9 ⫾0.2 4.7 ⫾0.1
Myoglobin, ␮g/l 51 ⫾4.6 54 ⫾3.2 52 ⫾543⫾4
CK, U/l 317 ⫾147 140 ⫾17 229 ⫾49 122 ⫾21
Cortisol, nmol/l 467 ⫾63 466 ⫾59 444 ⫾23 463 ⫾19
Insulin, pmol/l 35 ⫾733⫾4.3 31 ⫾341⫾4
Triglycerides, mmol/l 1.4 ⫾0.4 1.2 ⫾0.2 1.1 ⫾0.3 0.9 ⫾0.2
Values are means ⫾SE. CK, creatine kinase.
Fig. 4. Systolic blood pressure (mmHg) before (Pre) and after (Post) the 7-wk
intervention period for the 10-20-30 and the control (CON) group. *Different
(P⬍0.05) from Pre.
20 10-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

training. Iaia et al. (20) found an elevated short-term (0.5–2
min) performance, but no difference in the 10-km time when
endurance-trained subjects for 4 wk replaced their normal
training (⬃45 km/wk) with 30-s intervals at near-maximal
speed (8 –12 intervals per session) and reduced the amount of
training by ⬃64%. In agreement with the present study,
Bangsbo et al. (4) not only found improvement in short-term
performance, but also in performance at a 10-km (37 vs. 36
min) after 6 –9 wk with a reduced training volume of ⬃30%
and adding repeated 30-s near-maximal running intervals as
well as training sessions with four 4-min intervals at an
intensity of 90 –100% of HRmax. Other studies have shown
2– 6% improvements in endurance performance in endurance-
trained subjects when increasing the speed during training, but
the speed has been around the one corresponding to the V
˙O
2max
and the amount of training has not been reduced (25, 26, 45,
47, 48). Taken together it appears that not only the 30-s
near-maximal speed intervals are efficient in improving both
Fig. 5. Muscle Na
⫹
-K
⫹
pump subunits (␣1,
␣2, and ␤1), Na
⫹
/H
⫹
exchanger 1 (NHE1),
and monocarboxylate transporters 1 (MCT1)
and 4 (MCT4) expression before (open bars),
after 4 (hatched bars) and 7 (filled bars) wk of
the intervention period for the 10-20-30 (A)
and the control (B) group.
Table 3. Citrate synthase,
␤
-hydroxyacyl CoA dehydrogenase, and phosphofructokinase activity before (Pre) and after 4 wk
(Mid), and 7 wk (Post) of the 7-wk intervention period for the 10-20-30 and the control group
10-20-30 CON
Pre Mid Post Pre Mid Post
CS, ␮mol 䡠g dry wt
⫺1
䡠min
⫺1
34 ⫾336⫾432⫾232⫾431⫾227⫾2
HAD, ␮mol 䡠g dry wt
⫺1
䡠min
⫺1
18 ⫾119⫾117⫾115⫾216⫾114⫾1
PFK, ␮mol 䡠g dry wt
⫺1
䡠min
⫺1
193 ⫾18 168 ⫾17 182 ⫾22 241 ⫾32 201 ⫾6 183 ⫾49
Values are means ⫾SE. CS, citrate synthase; HAD, ␤-hydroxyacyl CoA dehydrogenase; PFK, phosphofructokinase.
2110-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

short- and long-term performance, but also, as demonstrated in
the present study, that training with 10-s speed intervals have
a major impact on performance.
In the present study V
˙O
2max
increased by 4% although the
total volume was reduced by 54%. It may be explained by the
HR being higher during the training than before the interven-
tion despite the short intense intervals (⬃40 vs. ⬃0% of
training time spent above 90% of HRmax; Fig. 1), suggesting
that a high cardiac stress in combination with a reduction
in training volume can elevate V
˙O
2max
. A number of other
studies have observed increase in V
˙O
2max
in trained subjects
when performing intensified training but without a reduction in
training volume (11, 18). In contrast, studies using 30-s near-
maximal speed intervals separated by 3 min of recovery does
not seem to lead to an increase in V
˙O
2max
(4, 20), suggesting
that continuing the running after the high speed in the 10-20-30
training concept highly stimulates the cardiovascular system.
On the other hand, the muscle oxidative system appears not to
have been affected, since the activity of muscle CS and HAD
was unchanged, which is in accordance with the findings in the
study by Bangsbo et al. (4). This is in contrast to observed
increases in oxidative enzymes with repeated short-term max-
imal exercise when performed with untrained individuals
where most types of metabolic stress may lead to oxidative
adaptations (8, 16, 28). The higher V
˙O
2max
may explain the
better 5-km performance after the 10-20-30 intervention pe-
riod. It was not due to a better running economy as it was
unchanged at a speed close to the pace during the 5-km run
(13.3 ⫾0.4 km/h). Other studies have found a lower oxygen
uptake during submaximal running after a period with 30-s
near-maximal intervals (4, 20). Apparently, the longer duration
of the intervals is important for the adaptations leading to a
better running economy. Likewise, there was no change in the
lactate response to submaximal exercise, suggesting that this is
not of critical importance for the 5-km performance.
We observed no changes in muscle Na
⫹
-K
⫹
pump subunits,
NHE1, MCT1, and MCT4. In contrast, the studies using 30-s
intervals for trained subjects have found increases in Na
⫹
-K
⫹
pump subunits ␣1, ␣2, and ␤1, NHE1, and MCT1 (4, 20). It
may be explained by the lower volume of high-speed running,
since the weekly time in the 10-20-30 training with high-speed
running was 150 –200 s which is approximately two-thirds of
that reported (⬎300 s/wk) in the other studies (4, 20). Another
possibility is that greater metabolic stress and changes in ion
homeostasis may be needed during training to obtain adapta-
tions in the ion transport proteins. During the near-maximal
repeated 30-s exercise intervals, muscle lactate rose to levels
⬃50 mmol/kg dry wt, muscle pH was lowered to ⬃6.98, and
accumulation of potassium in the blood was ⬃6.2 mmol/l,
likely reflecting concentrations above 10 mmol/l in the muscle
interstitium (33). Such changes were probably significant less
during the 10-s speed intervals used in the present study.
An interesting finding in the present study was that the
10-20-30 training period reduced the resting systolic BP in
these already trained subjects. It is well established that a
period of endurance and other types of training, such as soccer
training, lowers systolic BP of untrained subjects (2, 24, 35, 40,
41), but to our knowledge this is the first study to show that
intense training has this effect on systolic BP in trained
subjects. In a recent study by Gosselin et al. (17), no difference
in systolic and diastolic BP was found when comparing 20 min
of normal endurance training (⬃70% of V
˙O
2max
) with four
different high-intensity training protocols. However, the inten-
sities were significantly lower (⬍90% of V
˙O
2max
) than in the
present study (90 –100% of maximal intensity). The underlying
mechanism for the lowered BP is not clear but is likely
multifactorial and involves modulation in the activity of the
autonomic nervous system, neurohumoral and structural adap-
tations, as well as a reduction in systemic vascular resistance
(9, 37). The lack of change in resting HR rate may suggest that
the sympathetic outflow was not changed after the training
period. Further studies are needed to elucidate the mechanism
of the reduction in systolic BP. Nevertheless, the observed
5-mmHg decrease in systolic BP is of clinical relevance as a
decrease of that magnitude is likely to reduce the risk of
cardiovascular death by 10-15% (37).
A significant decrease in total cholesterol and LDL-choles-
terol was also observed after the 10-20-30 intervention period.
This finding suggests that the subjects obtained a better health
profile, since high levels of total and LDL-cholesterol are
associated with a higher risk of death and major adverse
cardiovascular events. Thus a reduction in LDL of 1 mmol/l
results in a 25% reduced cardiovascular risk, independent of
baseline LDL levels (12). In accordance with the present study
Randers et al. (41) also found a lowering of blood cholesterol
when using soccer training as an intervention. On the other
hand, in a number of studies the cholesterol levels were not
changed, although the subjects were untrained (2, 24, 35). The
diverging results may be related to differences in the training
intensity. In the study by Krustrup et al. (24) the subjects
performed moderate-speed running as the subjects in CON in
the present study (⬃80% of HRmax). The subjects in the study
by Nybo et al. (35) carried out repeated high-intensity running
(2-min intervals), but at an intensity below the speed eliciting
V
˙O
2max
(V
˙O
2max
⬃95% of HRmax), and significantly lower
than used in the 10-20-30 training (10 s at ⬃95% of maximal
Table 4. Blood lactate at rest and after submaximal and exhaustive treadmill running before (Pre) and after (Post) the 7-wk
intervention period for the 10-20-30 and the control group
Rest
Running Speed
Exhaustion
Recovery
9.9 km/h 12.4 km/h 1 min 3 min 5 min
10-20-30
Pre 1.3 ⫾0.2 1.8 ⫾0.3 3.2 ⫾0.7 10.3 ⫾1.1 10.1 ⫾1.1 10.2 ⫾1.4 9.8 ⫾1.2
Post 1.2 ⫾0.1 2.0 ⫾0.2 3.4 ⫾0.5 10.7 ⫾0.9 10.1 ⫾0.7 10.5 ⫾0.6 10.2 ⫾0.6
CON
Pre 1.0 ⫾0.1 1.6 ⫾0.2 3.1 ⫾0.4 9.4 ⫾0.9 8.9 ⫾0.4 10.1 ⫾0.7 9.9 ⫾0.8
Post 1.4 ⫾0.2 2.1 ⫾0.3 3.3 ⫾0.3 9.3 ⫾0.5 9.5 ⫾0.5 9.8 ⫾0.6 10.0 ⫾0.4
Values are means ⫾SE.
22 10-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

speed). This could indicate that the improvement of the plasma
lipid profile requires training at speeds above V
˙O
2max
. How-
ever, further studies are needed to examine the cause of these
changes in blood cholesterol.
In summary, the present study shows that the 10-20-30
training concept is efficient in increasing performance. Despite
a⬃50% reduction in training volume, V
˙O
2max
and performance
were significantly elevated in moderately trained subjects with-
out changes in running economy, muscle oxidative enzymes,
and ion transport proteins. In addition, the 10-20-30 training
led to reduced resting systolic BP and blood cholesterol,
suggesting a better health profile for already trained subjects.
Perspectives
The 10-20-30 training concept is easy adapted in a busy
daily schedule as it reduces time needed for training (⬃30 min
including warm-up) and positively affects short- and long-term
performance capacity. Furthermore, the present study is the
first to show an improved cardiovascular health profile in
trained subjects, which is in line with a prospective study by
Albert et al. (1) suggesting that habitual vigorous exercise, as
in the present study, diminishes the risk of death. The 10-20-30
concept is easy applicable for a variety of individuals ranging
from the sedentary to the elite runner where the 10-20-30
concept may be used prior to a competition as the marked
reduction in training volume in the present study (⬃50%) led
to significant improvements in performance. Since the 10-
20-30 concept deals with relative speeds and includes both
low-speed running and 2-min rest periods, individuals with
different fitness levels can train 10-20-30 together.
ACKNOWLEDGMENTS
We thank J. J. Nielsen and M. Thomassen for excellent technical assistance.
GRANTS
This work was supported by the Nordea Foundation (Nordea-fonden,
Copenhagen, Denmark).
DISCLOSURES
No conflicts of interest, financial or otherwise, are declared by the author(s).
AUTHOR CONTRIBUTIONS
Author contributions: T.P.G. and J.B. conception and design of research;
T.P.G. and J.B. performed experiments; T.P.G. and J.B. analyzed data; T.P.G.
and J.B. interpreted results of experiments; T.P.G. prepared figures; T.P.G. and
J.B. drafted manuscript; T.P.G. and J.B. approved final version of manuscript.
REFERENCES
1. Albert CM, Mittleman MA, Chae CU, Lee IM, Hennekens CH,
Manson JE. Triggering of sudden death from cardiac causes by vigorous
exertion. N Engl J Med 343: 1355–1361, 2000.
2. Andersen LJ, Randers MB, Westh K, Martone D, Hansen PR, Junge
A, Dvorak J, Bangsbo J, Krustrup P. Football as a treatment for
hypertension in untrained 30 –55-year-old men: a prospective randomized
study. Scand J Med Sci Sports 20, Suppl 1: 98 –102, 2010.
3. Aughey RJ, Murphy KT, Clark SA, Garnham AP, Snow RJ, Cameron-
Smith D, Hawley JA, McKenna MJ. Muscle Na
⫹
-K
⫹
-ATPase activity
and isoform adaptations to intense interval exercise and training in
well-trained athletes. J Appl Physiol 103: 39 –47, 2007.
4. Bangsbo J, Gunnarsson TP, Wendell J, Nybo L, Thomassen M.
Reduced volume and increased training intensity elevate muscle Na
⫹
-K
⫹
pump alpha2-subunit expression as well as short- and long-term work
capacity in humans. J Appl Physiol 107: 1771–1780, 2009.
5. Bickham DC, Bentley DJ, Le Rossignol PF, Cameron-Smith D. The
effects of short-term sprint training on MCT expression in moderately
endurance-trained runners. Eur J Appl Physiol 96: 636 –643, 2006.
6. Billat VL, Flechet B, Petit B, Muriaux G, Koralsztein JP. Interval
training at V
˙O
2max
: effects on aerobic performance and overtraining
markers. Med Sci Sports Exerc 31: 156 –163, 1999.
7. Burgomaster KA, Cermak NM, Phillips SM, Benton CR, Bonen A,
Gibala MJ. Divergent response of metabolite transport proteins in human
skeletal muscle after sprint interval training and detraining. Am J Physiol
Regul Integr Comp Physiol 292: R1970 –R1976, 2007.
8. Burgomaster KA, Heigenhauser GJ, Gibala MJ. Effect of short-term
sprint interval training on human skeletal muscle carbohydrate metabolism
during exercise and time-trial performance. J Appl Physiol 100: 2041–
2047, 2006.
9. Cornelissen VA, Fagard RH. Effects of endurance training on blood
pressure, blood pressure-regulating mechanisms, and cardiovascular risk
factors. Hypertension 46: 667–675, 2005.
10. Dubouchaud H, Butterfield GE, Wolfel EE, Bergman BC, Brooks GA.
Endurance training, expression, and physiology of LDH, MCT1, and
MCT4 in human skeletal muscle. Am J Physiol Endocrinol Metab 278:
E571–E579, 2000.
11. Esfarjani F, Laursen PB. Manipulating high-intensity interval training:
effects on V
˙O
2max
, the lactate threshold and 3000 m running performance
in moderately trained males. J Sci Med Sport 10: 27–35, 2007.
12. Evans M, Roberts A, Davies S, Rees A. Medical lipid-regulating therapy:
current evidence, ongoing trials and future developments. Drugs 64:
1181–1196, 2004.
13. Evertsen F, Medbo JI, Jebens E, Nicolaysen K. Hard training for 5 mo
increases Na
⫹
-K
⫹
pump concentration in skeletal muscle of cross-country
skiers. Am J Physiol Regul Integr Comp Physiol 272: R1417–R1424,
1997.
14. Franch J, Madsen K, Djurhuus MS, Pedersen PK. Improved running
economy following intensified training correlates with reduced ventilatory
demands. Med Sci Sports Exerc 30: 1250 –1256, 1998.
15. Gettman LR, Pollock ML, Durstine JL, Ward A, Ayres J, Linnerud
AC. Physiological responses of men to 1, 3, and 5 day per week training
programs. Res Q Exerc Sport 47: 638 –646, 1976.
16. Gibala MJ, Little JP, van EM, Wilkin GP, Burgomaster KA, Safdar
A, Raha S, Tarnopolsky MA. Short-term sprint interval versus traditional
endurance training: similar initial adaptations in human skeletal muscle
and exercise performance. J Physiol 575: 901–911, 2006.
17. Gosselin LE, Kozlowski KF, Devinney-Boymel L, Hambridge C.
Metabolic response of different high intensity aerobic interval exercise
protocols. J Strength Cond Res 2011 Nov 23. [EPub ahead of print]
18. Helgerud J, Hoydal K, Wang E, Karlsen T, Berg P, Bjerkaas M,
Simonsen T, Helgesen C, Hjorth N, Bach R, Hoff J. Aerobic high-
intensity intervals improve V
˙O
2max
more than moderate training. Med Sci
Sports Exerc 39: 665–671, 2007.
19. Iaia FM, Bangsbo J. Speed endurance training is a powerful stimulus for
physiological adaptations and performance improvements of athletes.
Scand J Med Sci Sports 20, Suppl 2: 11–23, 2010.
20. Iaia FM, Thomassen M, Kolding H, Gunnarsson T, Wendell J,
Rostgaard T, Nordsborg N, Krustrup P, Nybo L, Hellsten Y, Bangsbo
J. Reduced volume but increased training intensity elevates muscle
Na⫹-K⫹pump alpha1-subunit and NHE1 expression as well as short-
term work capacity in humans. Am J Physiol Regul Integr Comp Physiol
294: R966 –R974, 2008.
21. Juel C. Lactate-proton cotransport in skeletal muscle. Physiol Rev 77:
321–358, 1997.
22. Juel C. Training-induced changes in membrane transport proteins of
human skeletal muscle. Eur J Appl Physiol 96: 627–635, 2006.
23. Kraus WE, Houmard JA, Duscha BD, Knetzger KJ, Wharton MB,
McCartney JS, Bales CW, Henes S, Samsa GP, Otvos JD, Kulkarni
KR, Slentz CA. Effects of the amount and intensity of exercise on plasma
lipoproteins. N Engl J Med 347: 1483–1492, 2002.
24. Krustrup P, Nielsen JJ, Krustrup BR, Christensen JF, Pedersen H,
Randers MB, Aagaard P, Petersen AM, Nybo L, Bangsbo J. Recre-
ational soccer is an effective health-promoting activity for untrained men.
Br J Sports Med 43: 825–831, 2009.
25. Laursen PB, Shing CM, Peake JM, Coombes JS, Jenkins DG. Interval
training program optimization in highly trained endurance cyclists. Med
Sci Sports Exerc 34: 1801–1807, 2002.
2310-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org

26. Lindsay FH, Hawley JA, Myburgh KH, Schomer HH, Noakes TD,
Dennis SC. Improved athletic performance in highly trained cyclists after
interval training. Med Sci Sports Exerc 28: 1427–1434, 1996.
27. Lowry OH, Passonneau JV. A Flexible System of Enzymatic Analysis.
New York: Academic, 1972, p. 237–249.
28. MacDougall JD, Hicks AL, MacDonald JR, McKelvie RS, Green HJ,
Smith KM. Muscle performance and enzymatic adaptations to sprint
interval training. J Appl Physiol 84: 2138 –2142, 1998.
29. Madsen K, Franch J, Clausen T. Effects of intensified endurance
training on the concentration of Na,K-ATPase and Ca-ATPase in human
skeletal muscle. Acta Physiol Scand 150: 251–258, 1994.
30. Medbo JI, Jebens E, Vikne H, Refsnes PE, Gramvik P. Effect of
strenuous strength training on the Na-K pump concentration in skeletal
muscle of well-trained men. Eur J Appl Physiol 84: 148 –154, 2001.
31. Milesis CA, Pollock ML, Bah MD, Ayres JJ, Ward A, Linnerud AC.
Effects of different durations of physical training on cardiorespiratory
function, body composition, and serum lipids. Res Q Exerc Sport 47:
716 –725, 1976.
32. Millet GP, Jaouen B, Borrani F, Candau R. Effects of concurrent
endurance and strength training on running economy and V
˙O
2
kinetics.
Med Sci Sports Exerc 34: 1351–1359, 2002.
33. Mohr M, Krustrup P, Nielsen JJ, Nybo L, Rasmussen MK, Juel C,
Bangsbo J. Effect of two different intense training regimens on skeletal
muscle ion transport proteins and fatigue development. Am J Physiol
Regul Integr Comp Physiol 292: R1594 –R1602, 2007.
34. Nielsen JJ, Mohr M, Klarskov C, Kristensen M, Krustrup P, Juel C,
Bangsbo J. Effects of high-intensity intermittent training on potassium
kinetics and performance in human skeletal muscle. J Physiol 554:
857–870, 2004.
35. Nybo L, Sundstrup E, Jakobsen MD, Mohr M, Hornstrup T, Simon-
sen L, Bulow J, Randers MB, Nielsen JJ, Aagaard P, Krustrup P.
High-intensity training versus traditional exercise interventions for pro-
moting health. Med Sci Sports Exerc 42: 1951–1958, 2010.
36. Paavolainen L, Hakkinen K, Hamalainen I, Nummela A, Rusko H.
Explosive-strength training improves 5-km running time by improving
running economy and muscle power. J Appl Physiol 86: 1527–1533, 1999.
37. Pedersen BK, Saltin B. Evidence for prescribing exercise as therapy in
chronic disease. Scand J Med Sci Sports 16, Suppl 1: 3–63, 2006.
38. Pollock ML, Broida J, Kendrick Z, Miller HS Jr, Janeway R, Linne-
rud AC. Effects of training two days per week at different intensities on
middle-aged men. Med Sci Sports 4: 192–197, 1972.
39. Pollock ML, Miller HS, Linnerud AC, Cooper KH. Frequency of
training as a determinant for improvement in cardiovascular function and
body composition of middle-aged men. Arch Phys Med Rehabil 56:
141–145, 1975.
40. Randers MB, Nielsen JJ, Krustrup BR, Sundstrup E, Jakobsen MD,
Nybo L, Dvorak J, Bangsbo J, Krustrup P. Positive performance and
health effects of a football training program over 12 weeks can be
maintained over a 1-year period with reduced training frequency. Scand J
Med Sci Sports 20, Suppl 1: 80 –89, 2010.
41. Randers MB, Petersen J, Andersen LJ, Krustrup BR, Hornstrup T,
Nielsen JJ, Nordentoft M, Krustrup P. Short-term street soccer im-
proves fitness and cardiovascular health status of homeless men. Eur J
Appl Physiol 112: 2097–2106, 2012.
42. Saunders PU, Telford RD, Pyne DB, Peltola EM, Cunningham RB,
Gore CJ, Hawley JA. Short-term plyometric training improves running
economy in highly trained middle and long distance runners. J Strength
Cond Res 20: 947–954, 2006.
43. Slawinski J, Demarle A, Koralsztein JP, Billat V. Effect of supra-lactate
threshold training on the relationship between mechanical stride descrip-
tors and aerobic energy cost in trained runners. Arch Physiol Biochem 109:
110 –116, 2001.
44. Spurrs RW, Murphy AJ, Watsford ML. The effect of plyometric
training on distance running performance. Eur J Appl Physiol 89: 1–7,
2003.
45. Stepto NK, Hawley JA, Dennis SC, Hopkins WG. Effects of different
interval-training programs on cycling time-trial performance. Med Sci
Sports Exerc 31: 736 –741, 1999.
46. Turner AM, Owings M, Schwane JA. Improvement in running economy
after 6 weeks of plyometric training. J Strength Cond Res 17: 60 –67,
2003.
47. Westgarth-Taylor C, Hawley JA, Rickard S, Myburgh KH, Noakes
TD, Dennis SC. Metabolic and performance adaptations to interval
training in endurance-trained cyclists. Eur J Appl Physiol Occup Physiol
75: 298 –304, 1997.
48. Weston AR, Myburgh KH, Lindsay FH, Dennis SC, Noakes TD,
Hawley JA. Skeletal muscle buffering capacity and endurance perfor-
mance after high-intensity interval training by well-trained cyclists. Eur J
Appl Physiol Occup Physiol 75: 7–13, 1997.
49. Williams PT. Relationship of running intensity to hypertension, hyper-
cholesterolemia, and diabetes. Med Sci Sports Exerc 40: 1740 –1748,
2008.
24 10-20-30 Training Improves Performance and Health Profile •Gunnarsson TP et al.
J Appl Physiol •doi:10.1152/japplphysiol.00334.2012 •www.jappl.org