Effect of aerobic exercise training on cardiometabolic risk factors among professional athletes in the heaviest-weight class
Guo et al. Diabetol Metab Syndr
Effect of aerobic exercise training on cardiometabolic risk factors among professional athletes in the heaviest-weight class
Jianjun Guo 2
Yanmei Lou 0 1
Xi Zhang 0
Yiqing Song 0
0 Department of Epidemiology, Richard M. Fairbanks School of Public Health, Indiana University , Indianapolis, IN , USA
1 Department of Health Management, Beijing Xiao Tang Shan Hospital , Beijing , China
2 Centre for the Youth Sport Research and Development, China Institute of Sport Science , Tiyuguan Road, Beijing , China
Background: High prevalence of metabolic diseases among young professional athletes with large body sizes has raised growing attention. However, few studies specifically examined whether additional aerobic exercise provides cardiometabolic beneficial effect among these young athletes under regularly intensive strength training. Objective: We conducted a pilot trial to evaluate the effects of aerobic exercise on overall metabolic syndrome (MetS), individual MetS components, and aerobic capacity among metabolically unhealthy athletes in the heaviest-weight class. Methods: Forty-nine professional athletes aged 15-30 years had large body weights (mean weight of 131 ± 15.5 kg and 108 ± 15.8 kg and mean BMI of 39.4 ± 4.7 kg/m2 and 36.4 ± 5.1 kg/m2 for 26 men and 23 women, respectively). They completed a supervised moderate intensity (maximal heart rate: 140-170 beats/min for 30-70 min/day) aerobic exercise training for 12 weeks. We collected and measured metabolic parameters and aerobic capacity for all participants before and after 12 weeks of aerobic exercise training. Results: At baseline, 42 (86 %) of all 49 metabolically abnormal athletes were diagnosed as MetS according to the NCEP ATP III criteria (≥3 MetS components). After aerobic exercise training, 30 % (13/42) of MetS individuals tended to become free of MetS (<3 MetS components), decreasing the prevalence of MetS by 30.4 % (from 17 to 10) in women and 23.1 % (from 25 to 19) in men (P = 0.001). All individual components of MetS, including fasting glucose levels, lipid profile, and blood pressure, were also significantly improved (all P-values <0.05). Overall and central obesity indexes, including BMI, waist circumference, Waist-hip ratio, and abdominal fat ratio, were significantly decreased in men whereas only overall adiposity indexes, such as BMI and body fat percentage, were significantly reduced in women. Also, participants' aerobic capacities were also significantly enhanced with longer running distances and decreased heart rates (all P-values <0.05). Conclusions: Our pilot trial showed that moderate intensity aerobic exercise effectively improved cardiometabolic parameters in metabolically unhealthy professional athletes with routinely intensive strength training. Its long-term cardiovascular effects will be evaluated by future randomized controlled trials with well-designed exercise modalities.
Aerobic exercise; Cardiometabolic risk factors; Athletes; Metabolic syndrome
Cardiometabolic risk factors for diabetes mellitus and
cardiovascular diseases (CVDs) have been associated
with cardiovascular morbidity and mortality in the
general population . More recently, several reports found
that young, active, and seemingly “healthy” professional
athletes were not free of cardiometabolic risk, especially
those with large body sizes [2, 3]. American football
players with large body sizes were found to have 52 % higher
risk of heart disease mortality than individuals from
general population . Consistently, our previous survey
found that 261 Chinese professional athletes of strength
sports in the heaviest-body- weight-class had much
higher prevalence of metabolic risk factors and metabolic
syndrome (MetS) as an entity than their counterparts at
all other weight groups . Thus, it becomes imperative
to develop and implement effective preventive strategies
targeting cardiovascular health among young athletes in
the heavy-weight class.
Exercise has been widely accepted as an efficient
preventive strategy for improving cardiometabolic health .
Although cardiometabolic benefits of exercise have been
well documented, the relative effects of different types of
exercise (aerobic or anaerobic exercise) remain uncertain
due to sparse data . A meta-analysis for 12 randomized
clinical trials of aerobic exercise in patients with type 2
diabetes found that aerobic exercise had greater effects
on reduction of the glycosylated hemoglobin, BMI,
maximum heart rate and rise of VO2peak than resistance
exercise . We thus hypothesized that aerobic exercise may
provide additional beneficial cardiovascular effects on
its individual components of MetS and aerobic
capacity among professional athletes who routinely undergo
intensive strength training, most of being anaerobic
We conducted a pilot trial of 12-week moderate
intensity aerobic exercise intervention among young active
professional athletes in the heaviest-weight class, who
were metabolically unhealthy (at least one of four MetS
components with exception of abdominal obesity).
Research design and participants
This 12-week, one-arm trial targeted metabolically
abnormal athletes in heaviest-weight class in China (from
Hebei, Liaoning, Jilin, and Shanxi provinces). In total, 82
athletes in the heaviest-weight class were at the Sports
Institute for training and routinely examined for
cardiometabolic risk factors. They were screened by the initial
survey for eligibility. Finally, a total of 49 athletes aged
from 15 to 30 years, 26 men and 23 women, consent to
participate in this trial from July 2006 to December 2008.
Of them, 36 were weightlifting athletes, 10 were judo
athletes, and 3 were track and field throwing athletes.
All 49 participants included in this study were currently
professional athletes and in their off-season periods for
physical preparation. Among them, 13 were elite athletes
(international level) and 36 athletes were national level.
Generally, they received 4–5 h professional training per
day, 6 days per week. On average, each participant had
received 7-year training. The participants were instructed
to remain their regular training and lifestyle during the
study. This trial protocol was reviewed and approved by
the Institutional Review Board of China Institute of Sport
Sciences, Beijing, China and written informed consents
were obtained from all athletes who participated in the
Anthropometric examination, physical examination,
measure of blood lipid profile, and aerobic capacity test
were conducted for each participant according to the
study protocol and the corresponding information were
collected before and after the 12-weeks exercise
training. Height, weight, waist circumference, hip
circumference, sitting blood pressure, and body composition
were measured by professional physicians as previously
described in details . Briefly, height, waist
circumference, hip circumference in centimeter, and weight in
kilogram were measured with light clothes. Waist
circumference was measured at the midpoint between the
inferior costal margin and the superior border of the
iliac crest on the midaxillary line and hip circumference
was measured at the maximum extension of the
buttocks. Waist-hip ratio (WHR) is anthropometric indices
of central adiposity which was calculated by dividing the
waist circumference by the hip circumference. BMI was
estimated through the equation of weight/height2 (kg/
m2). Abdominal fat ratio was calculated by dividing the
abdominal fat volume by total abdominal volume. Blood
pressure (BP) was measured at least twice using a
calibrated conventional mercury sphygmomanometer. For
each participant, an average value of 2 blood pressure
measurements at a 3-min interval was used as the final
BP measurement. After 10 min of rest, the right-arm SBP
and DBP were recorded in the supine position for every
participant seated in a quiet room. Body fat percentage
was measured by bioelectrical impedance analysis
(DSMBIA) using the In-Body (3.0) body composition analyzer,
which is widely used in large-scale population studies
because of its reasonable quality, simple technology, and
affordable price .
Laboratory and biochemical measurements
After 10–12 h fasting, and avoiding of smoking,
drinking alcoholic beverages and coffee prior to the scheduled
appointment, participants sat at ease and had a rest for
5 min to prepare for the measurements. All athletes had
their training for 6 days per week, from Monday to
Saturday, and were at rest on Sunday. All fasting blood samples
were collected on Monday mornings so that athletes had
no exercise training for at least 36 h prior to their blood
collections. Venous blood samples were drawn from an
antecubital vein into potassium oxalate/sodium
fluoride anticoagulant tubes by using standard venipuncture
Plasma glucose was determined by hexokinase method,
with intra- and inter-assay coefficients of variations (CVs)
of less than 2.5 and 3.5 %, respectively. Enzymatic
colorimetric assay (Hitachi 7170A, Japan) was used for the
measurements of triglyceride (TG), high density
lipoprotein cholesterol (HDL-C), and low-density lipoprotein
cholesterol (LDL-C). The intra- and inter-assay CVs were
less than 1.5 and 3.0 %, respectively. Blood lactate was
assayed according to an enzymatic method as described
previously . Blood samples for lactate measure were
collected from each athlete at 5 min after his/her 12-min
Definition of MetS
The MetS is diagnosed according to the National
Cholesterol Education Program Adult Treatment Panel III
(NCEP ATP III) criteria in 2003 , which was defined
by the presence of three or more of the five individual
components listed below: (1) waist circumference for
abdominal obesity: men ≥102 cm or women ≥88 cm;
(2) elevated triglycerides (≥1.7 mmol/L); (3) lower
HDL-C (men <1.04 mmol/L and women <1.03 mmol/L);
(4) elevated BP (systolic ≥130 mmHg and/or
diastolic ≥85 mmHg); and (5) elevated fasting glucose
[≥6.1 mmol/L and (or) diabetes]. Participants in this pilot
trial were all metabolically abnormal with at least one of
the four MetS components (with exception of abdominal
Assessment of aerobic capacity
We administered Cooper 12-min running test to
indirectly evaluate the capacity of aerobic exercise, which is
widely adopted by researchers because of its effectiveness
and simple availability [12, 13]. According to the standard
guideline of 12-min running test for China’s college
students , the pass levels are 1600–1900 m for women
and 2000–2300 m for men. Good and excellent levels are
2000–2300 m and ≥2400 m for women and 2400–2700 m
and ≥2800 m for men, respectively. During 12 min, the
athletes tried their best to run around the 400-m athletic
field under the supervision of a professional coach. The
total distance of 12 min’ running was recorded for each
athlete. The test for everyone was conducted twice in
every other day, if the difference was greater than 5 %, the
test would be redone on the next day, and then the mean
of the two measurements was calculated for analyses.
Heart rates during exercise and 5 min after exercise were
assessed by POLAR® sports heart meter.
A supervised moderate intensity aerobic exercise training
In their routine strength training, the intensity,
frequency, and time of training varied across the types of
strength sports. Routinely, they have taken a 2–3 h
vigorous strength training (rating perceived exertion RPE:
17–20) twice daily for 6 days per week (from Monday
to Saturday). After the regular morning and afternoon
strength training, an additional 30 to 70-min aerobic
training per day was conducted by every athlete in this
trial. A 12-week training of moderate aerobic exercise
was conducted among all participants.
The appropriate fat-reducing exercise intensity
proposed by American College of Sports Medicine (ACSM)
is 50–70 % VO2max . The participants’ heart rates
were controlled between 140 and 170 beats/min,
equivalent to a moderate intensity fat reduction exercises at the
intensity between 50 and 60 % VO2max according to the
conversion function between the heart rate and
maximal oxygen uptake proposed by Astrand in 1960 .
The time of aerobic exercise was determined according
to the actual intensity of aerobic exercise. Thirty minutes
aerobic training was required to keep participants’ heart
rates ≥160 beats/min; if their heart rates were between
140 and 150 beats/min, 70 min exercise was required to
ensure an isometric exercise. The exercise types included
running, jogging, bicycle pedaling, and swimming. The
whole process of the aerobic exercise training was
supervised by qualified physical professionals to ensure the
required intensity and duration.
The sample size was calculated based on measurements
of HDL-C given a power of 90 % and a type I error
probability of 0.05. A sample size of 10 athletes could achieve
a power to detect a clinically significant effect on HDL-C
by 0.15 ± 0.13 mmol/L . Given a relatively high rate
of physical injuries observed among our professional
athletes who received both strength training and aerobic
exercise training, we allow for a 20 % maximal withdrawal
rate and noncompliance. As a result, at least 40 athletes
were needed to ensure sufficient statistical power. Finally,
we included a total of 49 athletes in this trial.
All continuous variables were presented as the
means ± standard deviations (SDs) for normal
distribution and median and quartiles for abnormal
distribution, respectively. Categorical variables were described
as count (frequency). The changes of demographic and
biochemical factors between pre- and
post-measurements were compared using matched t-tests or
relatedsamples Wilcoxon signed rank tests appropriately. The
prevalence of individual abnormal MetS components and
the MetS (≥3), metabolically abnormal (≥2), or
metabolically healthy (none with the exception of obesity) were
determined at baseline and after the trial. Chi square
tests were used to compare the transitions in the point
prevalence of MetS and individual MetS component
between baseline and end of the trial for men, women,
or both, respectively. The modifying effect by extreme
adiposity (BMI <40 kg/m2 and ≥40 kg/m2) was tested by
performing subgroup analysis. Level of significance was
two-tailed P < 0.05 for all statistical analyses. All data
analyses were performed using SPSS version 20 (SPSS
Inc., Chicago, IL, USA).
Basic characteristics of the study participants
As summarized in Table 1, all 49 young athletes (26
men and 23 women) in the heaviest-weight class with
a median age of 20 years (range 15–30) completed this
12-week aerobic exercise training (30–70 min/day)
without dropout or withdrawal. These athletes had a mean
weight of 131 kg for men and 108 kg for women (BMI
range 27.2–49.5 kg/m2) and a mean BMI of 39.4 kg/m2
for men and 36.4 kg/m2 for women. As expected, men
and women apparently differed in the demographic and
anthropometric measurements, such as age, BMI, and
waist circumference. All participants were
metabolically abnormal because they had at least one MetS
component with exception of abdominal obesity, including,
hypertension, hypertriglyceridemia, low HDL and fasting
Effects of aerobic exercises on body fatness
After this short-term moderate intensity aerobic
exercise intervention, body fatness of athletes was moderately
and significantly decreased. On average, body weights
were reduced by 3.7 kg (P < 0.0001) with a reduction of
6 % (95 % CI 0.2–1 %) in body fat percentage (P = 0.006)
in these young active athletes. There was a significant
sex difference in the effects of aerobic exercise on body
weight indexes. Overall and central obesity indexes,
including BMI, waist, WHR, and abdominal fat ratio,
were significantly decreased in men whereas global
obesity indexes, including BMI and body fat percentage,
were only significantly reduced in women.
Effects of aerobic exercises on levels of metabolic
biomarkers and aerobic capacity
All other individual MetS-related parameters, including
levels of BP, triglyceride, HDL, and fasting glucose, were
also significantly improved after a 12-week aerobic
exercise (all P-values <0.05). Levels of TC, TG, and LDL-C
were significantly decreased in both men and women
athletes (all P-values <0.05) while HDL-C levels were
significantly elevated by approximately 0.22 mmol/L in
women (P < 0.0001) and 0.15 mmol/L in men (P = 0.001).
Aerobic exercise had a significant effect on aerobic
capacity as a surrogate of combined physical and
cardiorespiratory fitness for both male and female athletes.
For women, there was significant 8 beats/min of heart
rate measured at 5 min after exercise slower than at
baseline (from 122 ± 11 beats/min to 114 ± 15 beats/min)
and a 284 m in the exhausted running distance in 12 min
(from 1711 ± 132 m to 1995 ± 226 m) higher at baseline
than after the trial. The improvement of aerobic
capacity were also found in men, from 1892 m (SD 260 m) at
baseline to 2259 m (SD 256 m) and from 124 beats/min
(SD 9 beats/min) to 118 beats/min (SD 12 beats/min)
for heart rate after running (all P-values <0.0001). Lower
levels of blood lactate after aerobic exercise indicated an
enhanced physical recovery, although the change was
marginally significant in men (P = 0.06).
Effects of aerobic exercises on MetS transition
In all, the overall prevalence of MetS decreased from 96.2
to 73.1 % in men and from 73.9 to 43.5 % in women after
aerobic exercise training (P = 0.004) shown in Fig. 1.
After aerobic exercise training for 12-week, 7/17 women
and 6/25 men athletes with MetS (≥3 MetS components)
at baseline transitioned to metabolically healthy (<3
MetS components), decreasing the prevalence of MetS by
30.4 % (from 17 to 10) in women and 23.1 % (from 25 to
19) in men (P = 0.001) as shown in Table 1. The
prevalence of each of five individual MetS components,
including central obesity, hypertriglyceridemia, low HDL levels,
hypertension, and impaired fasting glucose, tended to be
reduced by aerobic exercises in both men and women.
However, there was only statistical significance for the
decreased prevalence of low HDL-C prevalence from
69.6 % at baseline to 43.5 % at the end of training among
women (P = 0.03).
Effect modifications by BMI
These young active athletes may respond differentially to
aerobic exercise in terms of metabolic parameters based
on their levels of extreme obesity. Our subgroup
analysis stratified by two groups (BMI <40 kg/m2 and BMI
≥40 kg/m2) as shown in the Table 2. Overall, the effects
of aerobic exercise training on BP were more pronounced
in the high BMI group than the low BMI group.
Specifically, the decrement of SBP in high BMI group was
fourfold higher (P = 0.007), and the DBP change was
twofold higher in high BMI group than those of low BMI
Women, N = 23
Men, N = 26
Table 1 Comparison of weight, body composition and blood lipid of 49 athletes of different genders at pre-intervention
All continuous variables were presented as the mean ± SD and compared by paired sample t-tests for normal distributed variables, and median (lower quartile, upper
quartile) and related-samples Wilcoxon signed rand tests for variables with abnormal distribution. Categorical variable was presented as n (%) and compared by
fisher’s exact test
a The measurements were conducted 5 min after the training of aerobic exercise
group (P = 0.09). Basal SBP and DBP between athletes
with BMI <40 kg/m2 vs. those with BMI ≥40 kg/m2 were
128.9 vs. 140.8 mmHg (P = 0.02) and 85.2 vs. 83.1 mmHg
(P = 0.06), respectively. Not all the SBP/DBP values in
the low BMI group were normal. We further performed
an ANCOVA test adjusted for baseline BP and found
that the SBP lowering effect by exercise was modified by
baseline SBP values. After aerobic exercise training, the
High Level of TG
Impaired Fasting Glucose
Low Level of HDL-C
response of post-exercise heart rate at 5 min was slowed
by 7 beats/min (P = 0.008) in the high BMI group
compare with the low BMI group. None of the differences
of other measures between athletes with BMI ≥40 kg/
m2 and those with BMI <40 kg/m2 reached statistically
Our pilot trial of 49 metabolically unhealthy athletes in
the highest weight class has shown that 30–70 min/day
moderate intensity aerobic exercise for 12 weeks
elicited a significantly meaningful improvement in levels of
conventional cardiometabolic risk factors and exercise
Table 2 Measurement changes (post-treatment minus
pre-treatment) by different baseline
BMI classes among All 49 athletes
a Continuous variables were presented as the means ± standard deviations; the
P values were calculated by using t-test or Mann–Whitney U test
capacity. Significantly, aerobic exercise training for
12 weeks resulted in a 20 % increment of blood HDL-C
levels and nearly 24 % reversion from MetS to MetS-free
status. Aerobic exercise training also improved exercise
capacity as well as physical or cardiorespiratory fitness
among these young athletes in heaviest-weight class.
Despite its short-term and relatively small sample sizes,
this pilot trial provided some encouraging empirical data
that support the tremendous potential to implement
aerobic exercise programming into professional athletes to
prevent MetS-associated cardiovascular outcomes,
primarily due to their large body size and fatness.
MetS is defined by a constellation of risk factors of
cardiovascular disease, which might contribute to about
twofold increase in the risk of developing CVDs and
fivefold increase in the risk of type 2 diabetes mellitus in
future among general population . Previously, elite
athletes were always identified as the symbol of physical
health because of their young ages, heavy training loads,
large cardiorespiratory capacity, and regular participation
of competitions during their sports careers [19, 20].
However, in 1994, a study of retired National Football League
players found a 52 % greater risk of cardiovascular death
in linemen with large body weights than the general
population and 3 times higher risk of dying from
cardiovascular diseases than non-linemen . Recently, high
incidences of obesity, metabolic syndrome, and other
cardiovascular risk factors were also found in young
collegiate football linemen [22–24]. Similarly, our previous
study reported a MetS prevalence of 89 and 47 % among
male and female Chinese active strength athletes in the
highest weight class compared with a prevalence of 18
and 0 % in their respective counterparts at other weight
MetS is increasingly present in young professional
athletes with large body weights and it could greatly increase
risk of MetS-associated chronic diseases. Exercise is an
effective approach recommended by current guidelines for
both primary and secondary prevention of MetS and CVDs
. Previous evidence suggested that exercise improves
lipid profiles, reduces body fatness accumulation, lower BP
and blood glucose levels through its underlying pleiotropic
mechanisms [25, 26]. A meta-analysis has shown that
aerobic exercise led to a reduction of approximately 2 % in total
cholesterol, 3 % in LDL-C, and 5 % in TG, and an increase
of 3 % in HDL-C . In our study, most of the
cardiometabolic biomarkers were improved and HDL-C was
increased pronouncedly by the 12-week moderate intensity
aerobic exercise training. Similarly, Dalleck et al. found that
moderate aerobic exercise (60 % of heart rate) increased
HDL-C levels in healthy obese adults . Additionally,
we also found that athletes with higher BMI tend to have
more significant changes of cardiometabolic risk factors
in response to aerobic exercise intervention. We
classified all athletes into two subgroups by using a BMI cutoff
point of 40 kg/m2. This BMI cutoff point is only used for
classifying their body sizes among obese athletes but not
for assessing adiposity. The main purpose of such a
subgroup analysis was to assess metabolic parameters among
these heavy-weight class athletes with different body sizes.
After we adjusted the baseline BP, the effects of exercise on
SBP were still more pronounced in the high BMI group, but
the difference of changes in DBP was marginally significant
between these two BMI groups. It remains controversial
regarding which type and intensity of exercise is optimal
for cardiometabolic health. The appropriate fat-reducing
exercise intensity proposed by American College of Sports
Medicine (ACSM) is 40/50 to 70 % VO2max , with a
140–170 beats/min heart rate. Aerobic exercise is a type of
lower to moderate intensity physical activity (60–85 % of
the maximum heart rate), which promotes increased use
of oxygen in order to improve the overall body condition.
Aerobic exercise promotes the activation of various
antiinflammatory functions, which, in turn, may reduce the
risk of developing inflammation related chronic diseases,
such as hypertension, type 2 diabetes, and cardiovascular
disease . Collectively, several meta-analyses of 15–54
randomized controlled trials among patients or healthy
populations have suggested that ≥30 min/session aerobic
exercise for 4–104 weeks provided a moderate decreasing
effects on lipid levels (decrement: 2 % for TC, 3 % for
LDLC, and 5 % in women and 9 % in men for TG), weight loss
(decreasing weight: 1.7 kg, circumference: 2.12 cm), and BP
(−3.84 mmHg for SBP, −2.58 mmHg for DBP) [26, 27, 30–
33]. Taking together, these data recommend aerobic
exercise of 2–5 session/week for 20–60 continuous minutes at
a moderate intensity of 40–90 % of maximum heart rate for
cardiovascular health in the general population .
Athletes in the highest weight class usually undertake
intensive strength training, the necessary amount and
intensity of aerobic exercise to improve their
cardiometabolic health has not been described. Some evidence
suggested that aerobic exercise was more beneficial than
resistance exercise on improving glycemic control in
patients with type 2 diabetes; glycosylated hemoglobin
levels of patients with aerobic exercise were reduced by
1.97 mmol/mol as compared to resistance exercise .
Nevertheless, lack of sufficient evidence to confirm the
clinical importance of these statistical improvements
[8, 34, 35]. The findings from our pilot trial provided
suggestive evidence that aerobic exercise might
provide additional cardiovascular beneficial effects among
professional athletes who already received of intensive
strength training. Since all participants were professional
strength-trained athletes, our results may not be
generalizable to other athletes or the general population. Due
to our pilot trial design without randomly assigned
comparison groups, our study cannot assess the
cardiometabolic effects by aerobic exercise versus strength exercise.
Future long-term comprehensive studies focusing on the
appropriate types and intensity of exercise are warranted.
Several limitations in the present study should be
considered. First, this trial was not a randomized controlled
trial and lacked randomization and blind design, which
can allow for minimizing bias and confounding over the
trial duration. Second, the 12-week duration is relatively
short. The results cannot be drawn on the long-term
effect of aerobic exercise, although we observed a trend
towards an improvement in MetS risk factors. Third, the
sample size of 49 athletes was small to provide sufficient
power for detecting a clinically significant transition of
MetS and exploring potential effect modifiers. Fourth,
there may exist residual confounders such as lifestyle
and dietary status, although lifestyle and dietary
patterns were similar because the professional Chinese
athletes enrolled in this study lived in closed and standard
training facilities with a strict ban on cigarette smoking
and alcohol drinking. Fifth, there was lack of more
accurate measures to evaluate body composition (body fat
and lean body mass) and some metabolic biomarkers,
such as those of adipokines and systemic inflammation.
Sixth, we used Cooper 12-min running test to indirectly
evaluate the capacity of aerobic exercise although this
test is not an optimal measurements for capacity of
exercise. Seventh, we only tested absolute HR value 5 min
after exercise and did not test 1 min heart rate
recovery. Finally, we assumed that baseline levels of exercise
training of athletes were equivalent, although there may
have some differences of regular training in intensity and
amounts among these athletes in the highest weight class.
In summary, our pilot trial showed that a 12-week
supervised moderate intensity aerobic exercise training
provided additional beneficial effects on cardiometabolic
risk factors and exercise capacity among 49
metabolically abnormal athletes in the heaviest weight class who
received intensive strength training. Our findings
indicate that aerobic exercise training could be considered as
an effective model for improving cardiometabolic health
in professional athletes, especially those at high risk,
although future long-term and large-scale randomized
controlled trials with well-designed exercise
modalities are warranted to evaluate long-term cardiovascular
effects of exercise.
MetS: metabolic syndrome; BMI: body mass index; WHR: waist-to-hip ratio;
CVDs: cardiovascular diseases; HDL-C: high-density lipoprotein cholesterol;
LDL-C: low-density lipoprotein cholesterol; BP: blood pressure; SBP: systolic
blood pressure; DBP: diastolic blood pressure; VO2peak: peak oxygen uptake;
NCEP ATP III: National Cholesterol Education Program Adult Treatment Panel
III; CVs: coefficients of variations; TG: triglyceride; ACSM: American College of
Sports Medicine; VO2max: maximal oxygen uptake; SD: standard deviations.
JG designed and drafted the manuscript. YL wrote and edited the
manuscript. XZ and YL performed the statistical analysis. YL, YS and XZ contributed
to review and edit the manuscript. All authors read and approved the final
We acknowledge all the committed participants in this study. Drs. Zhang and
Song were supported by the Indiana University Health–Indiana University
School of Medicine Strategic Research Initiative Grant.
Compliance with ethical guidelines
The authors declare that they have no competing interests.
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