Adiposity Markers as Predictors of 11-Year Decline in Maximal Walking Speed in Late Midlife.

Background: Obesity is linked to poorer physical functioning in older adults, but impact of excess adiposity on loss of functional capacity in late midlife is unclear. This study examined associations between adiposity markers and 11-year change in maximal walking speed, a sensitive indicator of physical functioning, among adults aged 55 to 69 years. Method: Maximal walking speed over 6.1 m was assessed in 2000 and 2011 among Finnish men (n = 409) and women (n = 498) from the prospective Health 2000 Survey. Body mass index (BMI) and waist circumference were assessed in 2000. Generalized estimating equation models estimated changes in maximal walking speed by BMI and waist circumference, stratified by sex. Results: BMI greater than 30 kg/m2 was associated with accelerated decline in maximal walking speed particularly in women. Associations with waist circumference were nonsignificant. Conclusion: Late midlife obesity may speed up the decline in functional capacity as measured by maximal walking speed, especially in women.

Effects of aerobic and strength training on aerobic capacity, muscle strength, and gene expression of lymphomonocytes in patients with stable CAD.

This study examined the effectiveness, suitability, and safety of a mixed interval-type aerobic and strength training program (MIAST) on physical fitness in patients with stable coronary artery disease (CAD) without history of myocardial infarction (MI). Twenty-three patients with stable CAD were randomly assigned to a MIAST (n = 12; mean age 58.6 years) or control (n = 11; 63.3 years) group. The MIAST group participated in the progressive training program twice a week for 21 weeks. Peak oxygen uptake (VO2peak), workload, and exercise time were measured as were maximal muscle strength, serum lipids, glucose concentration, and the cross-sectional area (CSA) of knee extensors. The safety and suitability of the program were assessed by wireless electrocardiogram (ECG) monitoring and exercise diaries. VO2peak (6.9%; P < 0.05) and exercise time (11.2%; P < 0.05) improved significantly after 12 weeks of training in the MIAST group compared to the control group. Muscle strength (19.9%; P < 0.05) and CSA (2.2%; P < 0.05) increased, and serum lipids and blood glucose tended to decrease after the training. The successful training program (increase in maximal oxygen uptake) increased the gene expression of oxygen metabolism and decreased the gene expression of inflammation pathways in lymphomonocytes. The MIAST program, including interval-type aerobic and strength training, was safe, did not cause any adverse effects, and led to significant improvements in physical fitness in patients with stable CAD.

Change and determinants of total and context specific sitting in adults: A 7-year longitudinal study.

OBJECTIVES: To assess the stability and determinants of total and context specific sitting in a follow-up of adults. DESIGN: Longitudinal study. METHODS: Participants in the DILGOM cohort (n=3735, men 45%), reported daily sitting in five contexts (work-related, in vehicle, at home by the TV, at home at the computer, and elsewhere) in 2007 and 2014. Sociodemographic background, lifestyle and health were assessed in 2007. Total sitting comprised the sum of context specific sitting. Changes in, and determinants of context specific sitting, stratified by baseline age into young middle-aged (<53 years); late middle-aged (53-68 years) and older-aged (>68 years) were estimated by generalized linear mixed models. RESULTS: In 2007, total daily sitting was 7h 26min, 6h 16min, and 6h 3min in young middle-aged, late middle-aged and older-aged groups, respectively. Over 7 years, total sitting decreased on average by 26min. Sitting at the computer increased by 7-17min. The late middle-aged group also increased sitting by the TV, and decreased total, work-related, vehicle and elsewhere sitting. Occupational status determined context specific sitting, but somewhat differently in young and late middle-aged groups. Poor self-rated health determined less work-related and more sitting by the TV in the young, whereas good health determined less work-related sitting in the late middle-aged group. CONCLUSIONS: Self-reported sitting is a fairly stable behavior, with the exception for the late middle-aged group, where all context specific and total sitting changed significantly. Occupational status and health determined changes in sitting; however, somewhat differently by age group.

Gender, age and socioeconomic variation in 24-hour physical activity by wrist-worn accelerometers: the FinHealth 2017 Survey.

Assessing movement over 24 hours increases our understanding of the total physical activity level and its patterns. In the FinHealth 2017 Survey, a population-based health examination study, 940 participants between 25 and 93 years were instructed to wear an accelerometer (Actigraph GT9X Link) on their non-dominant wrist for 24 hours on 7 consecutive days. Physical activity information was extracted from 100-Hz triaxial 60-second epoch data as average vector magnitude counts per minute (VM cpm). Results were analyzed by gender, 10-year age-groups, employment status, and education. Hourly means were plotted and compared. Analyses included 915 participants (44% men) who wore the device at least 10 hours on 4 or more days, with mean wear time being 149.5 hours (standard deviation of 615.2 minutes).Women had higher average VM cpm than men (p < 0.001), with significant gender differences in all age-groups until 65 years and older. Total physical activity was lower with age, unemployment, and retirement, where the hourly patterns mirrored the findings. Our findings agree with previous large-scale wrist-accelerometry data, but extend current knowledge by providing data on gender and socioeconomic variation in physical activity across 24 hours in a population-based adult sample representing a broad age range.

Frequent sit-to-stand transitions and several short standing periods measured by hip-worn accelerometer are associated with smaller waist circumference among adults.

This cross-sectional study analysed the association of sedentary behaviour (SB) and standing with waist circumference. Finnish adults aged 30-75 years from a sub-sample of population-based Health 2011 Study used a hip-worn tri-axial accelerometer (Hookie AM20, Traxmeet, Ltd, Espoo, Finland) for seven days. Those 1405 participants (57% women) who used accelerometer at least four days, minimum of 10 hours/day, were included. SB and standing were analysed in 6s epochs using validated algorithm. Daily total time, daily number and accumulated time from bouts (30s-5min,30s-10min,30s-15min,30s 30min,>5min,>10min,>15min, >30min) as well as daily number of sit-to-stand transitions were determined. Waist circumference (cm) was measured in standardized way. Participants' mean age was 52 years (SD 12.2). Mean waist circumference was 97cm (SD 12.3) in men and 87cm (SD 12.7) in women. According to multivariable stepwise linear regression analysis, sit-to-stand transitions [standardised regression coefficient (ß)= -0.14, 95%CI -0.20 to -0.09], standing bouts of 30s-5min (ß= -0.21, 95%CI -0.26 to -0.15) and number of 30s-30min SB bouts (ß=0.12, 95%CI 0.06 to 0.17) were most strongly associated with waist circumference. Besides assessing total SB time, future studies should assess also different bout lengths of SB and sit-to-stand transitions and standing times should be assessed separately.

Projecting long-term trends in mobility limitations: impact of excess weight, smoking and physical inactivity.

BACKGROUND: Policy makers need disability projections for planning adequate services and measures for health promotion. The aim of this study is to provide projections on severe mobility limitations up to year 2044 and illustrate how the projected prevalence and the number of persons with severe mobility limitations are affected by potential changes in the modifiable risk factors, namely excess weight, physical inactivity and smoking. METHODS: We analysed the nationally representative, repeated measures Health 2000 and 2011 Surveys (BRIF8901) with 8615 and 6740 participants, respectively, aged 18 years and older. Severe mobility limitations were defined as major difficulties or unable to walk about half a kilometre. We applied a multistate model on repeated measures to account for both individual risk factors and their changes over time. RESULTS: The number of people with severe mobility limitations was projected to double by the year 2044 in Finland, due to the rapid ageing of the population. Eliminating half of the excess weight would reduce their number by one-fifth, while reductions in the prevalence of smoking and physical inactivity would have a minor impact. Even if excess weight, smoking and physical inactivity were completely eliminated, the number of persons with severe mobility limitations is projected to increase. CONCLUSIONS: Designing and implementing strategies to promote healthy weight are important to slow down the rapid increase in mobility limitations due to population ageing. Providing adequate health and social services for the increasing population with disabilities will nevertheless be an increasing national challenge.

Six-minute walk test: a tool for predicting maximal aerobic power (VO2 max) in healthy adults.

BACKGROUND: The 6-min walk test (6MWT) is cost-effective and well-documented field test for assessing functional exercise capacity and response to medical interventions in diverse patient groups, and predicting cardiorespiratory fitness among healthy people. OBJECTIVE: Assessments of cardiorespiratory fitness in terms of maximal aerobic power (VO2 max) have great potential in public health monitoring to predict future health, early retirement and ability to independent living. This study aimed to develop a prediction model for VO2 max based on 6MWT results among healthy adults. DESIGN: The study comprised of pilot and validation studies. In validation study, seventy-five 19- to 75-year-old adults (39 men, 36 women) were equipped with portable gas analyser and heart rate monitor. Participants performed 6MWT on a 15-m indoor track and maximal graded exercise test (GXT) on a treadmill. We evaluated performance of the developed prediction model among 1583 Finnish adults. RESULTS: Participant's mean walking distance was 652 m (SD ± 74). Their mean VO2 max in GXT and O2 uptake at the end of the 6MWT were 34·4 ml kg-1 min-1 (SD ± 7·6) and 27·2  ml kg-1 min-1 (SD ± 6·5), respectively. For men, the best predictors for VO2 max were walking distance, age, BMI, heart rate at the end of 6MWT and height, and for women, walking distance, age and weight. The predictors explained 82% and 79% of men's and women's measured VO2 max with the standard error of estimate of 3·6 ml kg-1 min-1 and 3·5 ml kg-1 min-1 , respectively. CONCLUSION: The 6MWT performed along a 15-m track is a valid field test for predicting VO2 max of healthy adults with accuracy of about 1MET.

Aerobic physical activity assessed with accelerometer, diary, questionnaire, and interview in a Finnish population sample.

This study evaluates the agreement between different methods to assess moderate to vigorous physical activity (MVPA) in a large sample of Finnish adults. Methods were classified and examined pairwise (accelerometer vs diary; questionnaire vs interview). Proportion of participants meeting the aerobic health-enhancing physical activity (HEPA) recommendation was compared pairwise between all four methods. The present study of 1916 adults aged 18-75 years (mean age 50 years, 57% women) is a sub-sample of population-based Health 2011 Study conducted by the National Institute of Health and Welfare in Finland. Participants used accelerometer for 7 days and completed physical activity (PA) diary during the same period. PA questionnaire and interview were completed retrospectively to assess typical weekly PA over the past year. Agreement between the methods was analyzed with paired samples t-test and Bland-Altman plot. Kappa-test was used to compare the prevalence of meeting the HEPA recommendation. The accelerometer resulted in 13 minutes (P < 0.001) higher weekly total amount of MVPA compared to diary. According to Bland-Altman plot, the 95% limit of agreement was from +273 to -247 in weekly minutes. The comparison between questionnaire and interview showed non-significant mean difference of 3 minutes (P = 0.60) in weekly MVPA, but the Bland-Altman plot showing the 95% limit of agreement from +432 to -427 in weekly minutes. Agreement of meeting HEPA recommendation was moderate between questionnaire and interview (κ = 0.43) but poor (κ = 0.20-0.38) between other comparisons. The inter-method differences were large especially at the individual level. Thus the assessment of PA is strongly method-dependent and not interchangeable.

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study.

BACKGROUND: Regular physical activity (PA) confers many positive effects on health and well-being. Sedentary behavior (SB), in turn, is a risk factor for health, regardless of the level of moderate to vigorous PA. The present study describes the levels of objectively measured SB, breaks in SB, standing still and PA among Finnish adults. METHODS: This cross-sectional analysis is based on the sub-sample of the population-based Health 2011 Study of Finnish adults. The study population consisted of 18-to-85-year old men and women who wore a waist-worn triaxial accelerometer (Hookie AM 20) for at least 4 days, for at least 10 h per day (n = 1587) during a week. PA and SB were objectively assessed from the raw accelerometric data using novel processing and analysis algorithms with mean amplitude deviation as the processing method. The data was statistically analyzed using cross-tabulations, analysis of variance and analysis of covariance. RESULTS: The participants were on average 52 years old, 57 % being women. Participants were sedentary 59 % of their waking wear time, mainly sitting. They spent 17 % of the time standing still, 15 % in light intensity PA, 9 % in moderate PA and less than 1 % in vigorous PA. Participants aged 30-39 years had the highest number of breaks in SB per day. Younger participants (<30 years of age) had more moderate and vigorous PA than older ones (≥60 years of age), and 30-60-year-olds had the greatest amount of light PA. CONCLUSIONS: Participants spent nearly 60 % of their waking time sedentary, and the majority of their daily PA was light. From a public health perspective it is important to find effective ways to decrease SB as well as to increase the level of PA. Our analysis method of raw accelerometer data may allow more precise assessment of dose-response relationships between objectively measured PA and SB and various indicators of health and well-being.

The contribution of travel-related urban zones, cycling and pedestrian networks and green space to commuting physical activity among adults - a cross-sectional population-based study using geographical information systems.

BACKGROUND: The current political agenda aims to promote active environments and physical activity while commuting to work, but research on it has provided mixed results. This study examines whether the proximity of green space and people's residence in different travel-related urban zones contributes to commuting physical activity. METHODS: Population-based cross-sectional health examination survey, Health 2011 study, and geographical information system (GIS) data were utilized. The GIS data on green space and travel-related urban zones were linked to the individuals of the Health 2011 study, based on their home geocoordinates. Commuting physical activity was self-reported. Logistic regression models were applied, and age, gender, education, leisure-time and occupational physical activity were adjusted. Analyses were limited to those of working age, living in the core-urban areas of Finland and having completed information on commuting physical activity (n = 2 098). RESULTS: Home location in a pedestrian zone of a main centre (odds ratio = 1.63; 95 % confidence interval = 1.06-2.51) or a pedestrian zone of a sub-centre (2.03; 1.09-3.80) and higher proportion of cycling and pedestrian networks (3.28; 1.71-6.31) contributed to higher levels of commuting physical activity. The contribution remained after adjusting for all the environmental attributes and individuals. Based on interaction analyses, women living in a public transport zone were almost two times more likely to be physically active while commuting compared to men. A high proportion of recreational green space contributed negatively to the levels of commuting physical activity (0.73; 0.57-0.94) after adjusting for several background factors. Based on interaction analyses, individuals aged from 44 to 54 years and living in sub-centres, men living in pedestrian zones of sub-centres, and those individuals who are physically inactive during leisure-time were less likely to be physically active while commuting. CONCLUSIONS: Good pedestrian and cycling infrastructure may play an important role in promoting commuting physical activity among the employed population, regardless of educational background, leisure-time and occupational physical activity. Close proximity to green space and a high proportion of green space near the home may not be sufficient to initiate commuting physical activity in Finland, where homes surrounded by green areas are often situated in car-oriented zones far from work places.

Heterogeneity in resistance training-induced muscle strength and mass responses in men and women of different ages.

Physical activity recommendations for public health include typically muscle-strengthening activities for a minimum of 2 days a week. The range of inter-individual variation in responses to resistance training (RT) aiming to improve health and well-being requires to be investigated. The purpose of this study was to quantify high and low responders for RT-induced changes in muscle size and strength and to examine possible effects of age and sex on these responses. Previously collected data of untrained healthy men and women (age 19 to 78 years, n = 287 with 72 controls) were pooled for the present study. Muscle size and strength changed during RT are 4.8 ± 6.1 % (range from -11 to 30 %) and 21.1 ± 11.5 % (range from -8 to 60 %) compared to pre-RT, respectively. Age and sex did not affect to the RT responses. Fourteen percent and 12 % of the subjects were defined as high responders (>1 standard deviation (SD) from the group mean) for the RT-induced changes in muscle size and strength, respectively. When taking into account the results of non-training controls (upper 95 % CI), 29 and 7 % of the subjects were defined as low responders for the RT-induced changes in muscle size and strength, respectively. The muscle size and strength responses varied extensively between the subjects regardless of subject's age and sex. Whether these changes are associated with, e.g., functional capacity and metabolic health improvements due to RT requires further studies.

Association of Physical Activity History With Physical Function and Mortality in Old Age.

BACKGROUND: We examined whether physical activity in early adulthood, late midlife, and old age as well as cumulative physical activity history are associated with changes in physical functioning and mortality in old age. METHODS: Data are from participants aged 65 years or older enrolled in the InCHIANTI study who were followed up from 1998-2000 to 2007-2008 (n = 1,149). At baseline, participants recalled their physical activity levels at ages 20-40, 40-60, and in the previous year, and they were categorized as physically inactive, moderately active, and physically active. Physical performance was assessed with the Short Physical Performance Battery and self-reported mobility disability was evaluated at the 3-, 6- and 9-year follow-up. Mortality follow-up was assessed until the end of 2010. RESULTS: Physical inactivity at baseline was associated with greater decline in Short Physical Performance Battery score (mean 9-year change: -2.72, 95% CI: -3.08, -2.35 vs -0.98, 95% -1.57, -0.39) and greater rate of incident mobility disability (hazard ratio 4.66, 95% CI 1.14-19.07) and mortality (hazard ratio 2.18, 95% CI 1.01-4.70) compared to physically active participants at baseline. Being physically active throughout adulthood was associated with smaller decline in physical performance as well as with lower risk of incident mobility disability and premature death compared with those who had been less active during their adult life. CONCLUSIONS: Higher cumulative physical activity over the life course was associated with less decline in physical performance and reduced rate of incident mobility disability and mortality in older ages.

Educational differences in estimated and measured physical fitness.

BACKGROUND: Available information about the association between education and physical fitness (PF) is scarce. The purpose of this study was to examine educational differences in PF in the working age population using different methods to assess PF. METHODS: The Health 2000 Survey was carried out for adults aged ≥ 30 years (n = 8028) in Finland. For this study, 30-54-year-old men and women with data on PF and physical activity (PA) were selected (n = 3724). PF was assessed by self-estimated overall physical fitness and running ability, a physician's estimation of a participant's working capacity, the trunk extensors' endurance and hand grip strength tests. The highest educational qualification taken by the participant was used as a measure of education. The analyses were adjusted for age, PA, BMI, smoking and chronic diseases. RESULTS: PF was best in the high-educated men and women. The educational differences were minor in self-estimated overall PF. Adjusting for the covariates, the differences in self-estimated running ability and working capacity decreased. The educational differences in the trunk extensors' endurance test were independent of covariates. PA and other health behaviours contributed most to the differences. CONCLUSION: People with high education had better PF irrespective of the method used to assess PF. A large amount of the educational differences could be explained by PA and other health behaviours. More research is needed to understand the determinants of educational differences in PF.

Educational differences in self-rated physical fitness among Finns.

BACKGROUND: The high educated live longer and healthier lives when compared to the low educated. Physical fitness as a health indicator reflects the level of physical activity along with other health-influencing factors such as obesity, smoking, chronic diseases and individual training effects. Studies support that self-rated physical fitness correlates with objectively measured physical fitness well. However, the educational differences in self-rated physical fitness are not known. METHODS: Our aim was to study educational differences in self-rated physical fitness in Finnish population. The data were collected in 2007 for a cross-sectional population based National FINRISK Study. The analyzed data included 2722 men and 3108 women aged 25 to 74 years. Statistical method was ordinal logistic regression. RESULTS: Longer educational career was associated with better self-rated physical fitness. The educational differences in self-rated physical fitness were largely explained by health behavior. Leisure-time physical activity explained fully and body mass index partly the educational differences in self-rated physical fitness among men. The combination of body mass index, history of chronic diseases and smoking explained the differences fully among men and partly among women. Leisure-time, occupational and commuting physical activities, body mass index, history of chronic diseases and smoking together explained all educational differences in self-rated physical fitness among both genders. CONCLUSIONS: Although educational differences in self-rated physical fitness were found, they were explained by health behavior related factors. Leisure-time physical activity offered the strongest single explanation for the educational differences in self-rated physical fitness. Thus, possibilities for leisure-time physical activity should be increased especially among the low educated.

Effects of concurrent strength and endurance training on physical fitness and symptoms in postmenopausal women with fibromyalgia: a randomized controlled trial.

OBJECTIVE: To examine the effectiveness of concurrent strength and endurance training on muscle strength, aerobic and functional performance, and symptoms in postmenopausal women with fibromyalgia (FM). DESIGN: Randomized controlled trial. SETTING: Local gym and university research laboratory. PARTICIPANTS: Twenty-six women with FM. INTERVENTION: Progressive and supervised 21-week concurrent strength and endurance training. MAIN OUTCOME MEASURES: Muscle strength of leg extensors, upper extremities, and trunk; peak oxygen uptake (Vo(2)peak), maximal workload (Wmax), and work time; 10-m walking and 10-step stair-climbing time and self-reported functional capacity (Health Assessment Questionnaire); and symptoms of FM. RESULTS: After concurrent strength and endurance training, the groups differed significantly in Wmax (P=.001), work time (P=.001), concentric leg extension force (P=.043), walking (P=.001) and stair-climbing (P<.001) time, and fatigue (P=.038). The training led to an increase of 10% (P=.004) in Wmax and 13% (P=.004) in work time on the bicycle but no change in Vo(2)peak. CONCLUSIONS: Concurrent strength and endurance training in low to moderate volume improves the muscle strength of leg extensors, Wmax, work time, and functional performance as well as perceived symptoms, fatigue in particular. Concurrent strength and endurance training is beneficial to postmenopausal women with FM without adversities, but more extensive studies are needed to confirm the results.

Acute heavy-resistance exercise-induced pain and neuromuscular fatigue in elderly women with fibromyalgia and in healthy controls: effects of strength training.

OBJECTIVE: To examine heavy-resistance exercise-induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training. METHODS: Thirteen elderly women with FM (mean+/-SD age 60+/-2 years) and 10 healthy women (mean+/-SD age 64+/-3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale. RESULTS: The strength training led to large increases in maximal force and EMG activity of the muscles and contributed to the improvement in loading performance (average load/set) at week 21. The fatiguing loading sessions typically applied in strength training before and after the experimental period caused remarkable and comparable acute decreases in maximal force and increases in blood lactate concentration in both groups. Acute exercise-induced muscle pain increased similarly in both groups, and the pain level in women with FM was lowered after the 21-week training period. CONCLUSION: The increased strength in women with FM improved high-load performance and also seemed to attenuate perceived pain. Acute exercise-induced neuromuscular changes and the time course of muscle pain in women with FM were comparable with findings in healthy controls, which suggests a typical fatiguing process and a similar trainability of the muscles in elderly women with FM.

Maximal force, force/time and activation/coactivation characteristics of the neck muscles in extension and flexion in healthy men and women at different ages.

This study examined the force production characteristics, activation/coactivation and endurance capacity of the neck extension and flexion muscles in healthy men (n=29) and women (n=28) divided into three age groups (18-26 years, 30-37 years and 45-55 years). Force and electromyography (EMG) measurements were performed during the maximal voluntary isometric extension and flexion actions. This was followed by an endurance test (ET; 60% force level of maximal voluntary contraction sustained until exhaustion), after which the force and EMG recordings were repeated. Men were both stronger and had higher values (P<0.001) for explosive force (rate of force development, RFD) than women in both actions. Younger subjects of both genders exhibited larger (P<0.05 in women) RFD values than older subjects in extension. The coactivation of the antagonist muscles during the maximal extension or flexion did not differ significantly between men and women, but the coactivation of the antagonists was larger (P<0.05) in the older age groups than in the youngest group. Women maintained the 60% force level longer than men in both actions (extension, P<0.001; flexion, not significant). The fatiguing loading led to significant decreases in maximal isometric force (P<0.001) and RFD (P<0.01-0.001), but these relative decreases did not differ between the groups. In conclusion, large gender differences in the voluntary extension and flexion force production characteristics of the neck muscles did exist, as reported earlier for other muscles of the body. No age-related differences were observed in maximal force of the extension and flexion actions within the age ranges of the subject groups studied here, but the older subjects exhibited greater coactivation and produced lower force values in the early portions of the force/time curve of the extension than the youngest group. The data indicate that explosive force production may be sensitive to aging earlier than maximal strength in the case of the neck extensor muscles.

Effects of strength training on muscle strength, cross-sectional area, maximal electromyographic activity, and serum hormones in premenopausal women with fibromyalgia.

OBJECTIVE: To examine the effects of strength training on basal concentrations and acute responses of serum hormones, and their possible interrelationships with training induced muscle hypertrophy and strength gains of the knee extensor muscles in women with fibromyalgia (FM) and healthy controls. METHODS: Twenty-one premenopausal women with FM were randomized to 21 week strength training (FMT; n = 11) or control (FMC; n = 10) groups. Twelve premenopausal sedentary healthy women served as controls (HC). Surface electromyographic (EMG) activity, maximal unilateral isometric force of the right knee extensors, and muscle cross-sectional area (CSA) of the quadriceps femoris throughout the lengths of 3/12 to 12/15 of the femur (Lf) were measured. Serum concentrations of total and free testosterone and growth hormone (GH) were analyzed at rest and in pre- and post-exercise conditions, while levels of insulin-like growth factor and dehydroepiandrosterone sulfate were measured at rest only. RESULTS: Mean (SD) maximal force increased by 18% (10%) (p < 0.001) in the FMT group, and by 22% (12%) (p < 0.001) in the HC, while in the FMC it remained unchanged. Maximum integrated EMG of the agonists (VL + VM/2) increased in HC by 22% (p < 0.05) and in the FMT by 19% (p < 0.05). Significant increases in the CSA of the QF were observed at 5 to 12/15 Lf in FMT (p < 0.05-0.01) and at 3 to 12/15 Lf in HC (p < 0.05-0.001), while in FMC the CSA remained unchanged. No training induced changes occurred in the basal concentrations of serum hormones examined. A significant acute increase took place in the mean concentration of GH at pre-training in HC (p < 0.01) and in the FMT (p < 0.05), while at post-training the elevations after the loading (p < 0.001 and 0.05) remained elevated up to 15 min (p < 0.05) in HC and up to 30 min (p < 0.01) post-loading in the FMT. CONCLUSION: Both the magnitude and time course of adaptations of the neuromuscular system to resistance training in women with FM were completely comparable to those taking place in healthy women. Basal levels of the anabolic hormones seem to be similar in women with FM compared to age matched healthy women. Observations recorded during the acute loading conditions might be considered an indication of the training induced adaptation of the endocrine system, showing that the acute GH response may become systematic after strength training in both women with FM and controls.