Physical training in the fire station and firefighters' cardiovascular health.

BACKGROUND: Few fire departments in Québec have a diversified health promotion programme. Yet, many allow firefighters to physically train during working hours. AIMS: To compare the weekly physical activity (PA) level and cardiovascular health indicators of firefighters who physically train on duty to those who do not. METHODS: Participants underwent a cardiovascular health assessment and completed an online questionnaire. RESULTS: One hundred and five full-time male firefighters participated in the study. Two groups were formed: firefighters who physically train while on duty (E, n = 64) and firefighters who do not (NoE, n = 41). Following statistical adjustments, off-duty weekly PA was not different between the two groups (E: 239 ± 224 versus NoE: 269 ± 249 min, P = 0.496); however, total weekly PA was higher (P = 0.035) in E (381 ± 288 min) than in NoE (274 ± 200 min). A difference was also observed in obesity prevalence measured with waist circumference (E: 9% versus NoE: 27%, P = 0.026) and in physical inactivity prevalence (E: 0% versus NoE: 27%, P < 0.001). After statistical adjustments, E firefighters have a significantly lower waist-to-height ratio than NoE firefighters (E: 0.51 ± 0.05 versus NoE: 0.54 ± 0.05, P = 0.017). CONCLUSIONS: Results show that firefighters who physically train while on duty have a higher total PA level on a weekly basis and have better cardiovascular health indicators. Our findings suggest that fire services should promote physical training while on duty to improve firefighters' cardiovascular health.

Cardiovascular disease risk in female firefighters.

BACKGROUND: Female firefighters are in the minority in the Québec firefighter population and worldwide. To our knowledge, no study has focused on cardiovascular risk factors in female firefighters, and further research in this area is needed to evaluate and reduce the risk of on-duty sudden cardiac death. AIMS: To evaluate the prevalence of cardiovascular disease (CVD) risk factors in female firefighters in Québec. METHODS: A cross-sectional study using an online questionnaire to evaluate lifestyle and CVD risk factors and symptoms. RESULTS: Forty-one female firefighters (age: 38.2 ± 9.9 years) participated in this study, representing ~7% of all female Québec firefighters. The prevalence of obesity (body mass index ≥ 30 kg/m2), hypertension, dyslipidaemia, type 2 diabetes mellitus, smoking and physical inactivity was 12% (95% confidence interval [CI] 4-26%), 5% (95% CI 0.6-19%), 5% (95% CI 0.6-19%), 3% (95% CI 0.1-14%), 14% (95% CI 5-29%) and 62% (95% CI 5-7%), respectively. Among survey participants, 76% (59-88%) had moderate to high CVD risk according to the 2013 American College of Sports Medicine guidelines. Eighty-two per cent of participants did not meet the National Fire Protection Association's required cardiorespiratory fitness standard of 12 metabolic equivalents. CONCLUSIONS: A high proportion of female firefighters in this study were at moderate to high risk of CVD. These findings suggest that they would benefit from healthy lifestyle initiatives.

Daily physical education in primary school and physical activity in midlife: the Trois-Rivières study.

AIM: Although a commonly stated purpose of physical education (PE) classes is to foster life-long participation in physicalactivity (PA), few longitudinal studies have assessed the impact of childhood PE interventions on PA as an adult. The Trois-Rivières Growth and Development Study provided a unique opportunity to address this question. METHODS: In 2008, 86 participants in the original 1970-1977 Trois-Rivières Study (44 women and 42 men aged 44.0 ± 1.2 years) completed a questionnaire examining their current PA level and different correlates of PA (i.e. individual's intention to engage in PA, perceived enjoyment, usefulness and ease in engaging in PA, perceived social support and social norms). Participants had initially been assigned to either an experimental program (5 h/week of specialist-taught PE) or a control group (40 min/week of home-room teacher-taught PE) from grades 1 to 6. RESULTS: There were no current differences between the experimental and control groups neither in the frequency, duration nor volume of PA undertaken at the current follow-up. Furthermore, no differences between groups were found for any of the PA correlates examined. CONCLUSION: Providing daily PE throughout primary school seems insufficient to ensure that individuals will remain active in midlife. The development of a life-course approach to PA promotion is thus warranted.

Greater physical fitness is associated with better air ventilation efficiency in firefighters.

Firefighting is a hazardous task associated with a heavy workload where task duration may be limited by air cylinder capacity. Increased fitness may lead to better air ventilation efficiency and task duration at a given heavy work intensity. This study compared performance, air ventilation and skeletal muscle oxygen extraction during a maximal graded walking test (GWT), a 10 METS (metabolic equivalent) treadmill test (T10) and a simulated work circuit (SWC). Participants (n = 13) who performed the SWC in a shorter time had significantly lower air cylinder ventilation values on the T10 (r = -0.495), better peak oxygen consumption (r = -0.924) during the GWT and significantly greater skeletal muscle oxygen extraction during the SWC (HbDiff, r = 0.768). These results demonstrate that the fastest participants on the SWC had better air ventilation efficiency that could prolong interventions in difficult situations requiring air cylinder use.

Daily quality physical education in childhood and adult bone density.

AIM: Previous studies, mainly of self-selected athletes, have suggested that childhood activities can have a prolonged influence on bone mineral density. This investigation explored whether experimentally assigned daily quality physical education (PE) during childhood influenced bone density at an age of 42.8±1.5 years. METHODS: Participants from the Trois-Rivières Longitudinal Study were divided into 4 groups: the first 2 groups (19 women and 21 men) had received 5 h/week of specialist-taught PE in primary school in 1970-1977, whereas the third and fourth groups (10 women and 10 men) had followed the standard PE programme of 40 min/week. RESULTS: Bone densities, measured by dual X-ray absorptiometry (lumbar vertebrae and femoral neck), did not differ significantly between experimental and control subjects. CONCLUSION: This result may reflect a normal or even a faster decrease of bone mineral density in experimental subjects over the 30 years since completion of the program, or an intervention that was designed to enhance cardiorespiratory and muscular fitness rather than bone health.

Changes in adiposity and body mass index from late childhood to adult life in the Trois-Rivières study.

This study explored tracking of the body mass index (BMI) in a representative subgroup of subjects (95 women and 96 men) who were involved in the Trois-Rivières Growth and Development Study by testing autocorrelations between data for 10, 11, and 12 years and corresponding values at 34 years of age. Tracking of skinfold measurements (subscapular, triceps, suprailiac, and abdominal, and their sum) over the same intervals (60 women and 52 men) was also evaluated. After the age of 12 years, subjects showed a similar development of absolute values, whether they were from the experimental or the control group. Gains of the BMI and skinfold thicknesses showed expected gender differences. In particular, men showed larger gains of the BMI and abdominal skinfolds, whereas women had larger gains in the triceps skinfold. Increases in the sum of four skinfolds did not differ significantly between men and women, suggesting that the larger BMI gains in men were caused by a larger relative increase of fat-free mass in the men. Tracking coefficients for the BMI were lower in men than in women between 10, 11, 12, and 34 years (r = 0.43-0.49 vs. r = 0.64-0.70, P < 0.001). The results indicate that the body composition of participants in the Trois-Rivières Growth and Development study developed in a similar fashion whether or not their primary school instruction included additional physical education instruction. The results also suggest that prediction of adult obesity based on childhood BMI measurements is more effective in girls than in boys.

Physiological responses to cycling for 60 minutes at maximal lactate steady state.

Changes in physiological variables during a 60-min continuous test at maximal lactate steady state (MLSS) were studied using highly conditioned cyclists (1 female and 9 males, aged 28.3 +/- 8.1 years). To determine power at MLSS, we tested at 8-min increments and interpolated the power corresponding to a blood lactate value of 4 mmol/L. During the subsequent 60-min exercise at MLSS, we observed a sequential increase of physiological parameters, in contrast to stable blood lactate. Heart rate drifted upward from beginning to end of exercise. This became statistically significant after 30 min. From 10-60 min of exercise, a change of +12.6 +/- 3.2 bpm was noted. Significant drift was seen after 30 min for the respiratory exchange ratio, after 40 min for the rate of perceived exertion using the Borg scale, and after 50 min for % VO(2)max/kg and minute ventilation. This slow component of VO(2)max may be the result of higher recruitment of type II fibers.

Daily primary school physical education: effects on physical activity during adult life.

PURPOSE: The purpose of this investigation was to study the influence of a daily primary school physical education program on physical activity (PA) level, attitudes toward physical activity, and perceptions of barriers to physical activity during adulthood. METHODS: We compared two groups: 1) an experimental group of men and women (N = 147) who had received five physical education sessions per week throughout their 6 yr of primary school education in the early 1970s; and 2) a control group, drawn from the data bank of the Québec Health Survey, and matched for age, gender, and socioeconomic profile (N = 720). Experimental and control subjects filled out an identical questionnaire about their current physical activity level, their attitudes toward PA, and their perceptions of barriers to PA. The control group was stratified to obtain the same sociodemographic profile as the experimental group. RESULTS: Our principal results were: 1) a frequency distribution that showed a higher rate of physical activity in experimental women than in control women; 2) similar intentions to exercise and attitudes toward exercise in the experimental and control groups, with no differences in opportunities for exercising or in the support received from their family and friends; and 3) a lower prevalence of regular smokers in experimental men than in control men. There were also some differences in the types and frequency of physical activities selected between experimental and control subjects. CONCLUSION: Our results strongly suggest that daily physical education at the primary school level has had a significant long-term positive effect on the exercise habits on women, despite similar perceived barriers, attitudes, and intention to exercise in the two groups. The program has also had a significant health effect in men, substantially reducing the risk of becoming a regular smoker. Because the program was not specifically designed to promote health, we hypothesize that a health-oriented physical education program could have an even stronger effect.

Attitude and enduring involvement of older adults in structured programs of physical activity.

The purpose of this paper is to measure the influence of the affective attitudinal domain upon the intentions of a group of older adults participating in structured programs of physical activity offered in a community recreation setting. The subjects were 118 seniors participating in either a fitness, aqua-fitness, or golf program in metropolitan Ottawa. The group comprised of 65 women and 53 men were, in the most part, between 55 and 70 years of age. A questionnaire measuring attitude towards physical activity was developed. A stepwise regression analysis of intention to participate on attitudes showed that most of the variance in intention (69.0%) was explained by the variable "good/beneficial," i.e., seniors perceived the programs as being good and beneficial to them. It is recommended that further investigation of affective factors related to attitude be carried out to develop strategies to maintain seniors involvement in physical activity programs.

Lactate threshold determination: a Monte Carlo comparison of two interpolation methods.

A heuristic model of the relation between blood lactate (L) and VO2 during exercise was used to assess the comparative merits of two methods of reference threshold determination: the habitual linear interpolation method (LT), and a new method using inverse parabolic (second degree) interpolation (PT); the new method capitalizes on the demonstrated curvilinear relation between blood lactate and O2 uptake. Both types of interpolated thresholds were computed, and their error evaluated against the "true" 4-mmol lactate threshold. A combined parametric and Monte Carlo investigation showed that parabolic thresholds are generally superior, being less biased and more precise than their linear counterpart.

Physiological adjustments of facial cooling during exercise.

Physiological and metabolic output responses to facial cooling during a graded maximal exercise and a prolonged submaximal exercise lasting 30 min at 65% VO2 max were investigated in five male subjects. Pedalling on a cycle ergometer was performed both with and without facial cooling (10 degrees C, 4.6 M.S-1). Facial cooling at the end of greated maximal exercise apparently had no effect on plasma lactate (LA), maximal oxygen consumption (VO2 max), maximal heart rate (HR max), rectal temperature (Tre), work load, lactate threshold (LT), ventilatory threshold (VT) and onset of blood lactate accumulation (OBLA). However, the response to facial cooling after prolonged submaximal exercise is significantly different for heart rate and work load. The results suggest that facial wind stimulation during maximal exercise does not produce a stress high enough to alter the metabolic and physiological responses.

Hematological variations at rest and during maximal and submaximal exercise in a cold (0 degree C) environment.

The affect of negative thermal stress on hematological variables at rest, and during submaximal (sub ex) and maximal exercise (max ex) were observed for young males who volunteered in two experimental sessions, performed in cold (0 degree C) and in normal room temperature (20 degrees C). At rest, hematological variables such as RBC and derivates Hb and Hct were significantly increased (P less than 0.05) during cold stress exposure, while plasma volume decreased. The findings of this study suggest that the major factor inducing hypovolemia during low thermal stress can be imputed to local plasma water-shift mechanisms and especially to a transient shift of plasma water from intra- to extravascular compartments. Rest values for WBC and platelets (Pla) were also slightly increased during cold stress exposure. However this increase can partly be related to hemoconcentration but also to the cold induced hyperventilation activating the lung circulation. Maximal exhaustive exercise induced, in both experimental temperatures, significant (P less than 0.05) increments of RBC, Hb, Hct, and WBC while plasma volume decreased. However, Pla increase was less marked. On the other hand, cold stress raised slightly the observed variations of the different hematological variables. Submaximal exercise induced a similar, though non-significant, pattern for the different hematological variables in both experimental conditions. Observed plasma volume (delta PV%) reduction appears during exercise. However cold stress induced resting plasma volume variations that are transferred at every exercise level. Neither exercise nor cold inducement significantly modified the hematological indices (MCH, MCV, MCHC). In conclusion hematological variables are affected by cold stress exposure, even when subjects perform a physical activity.

Metabolic and hormonal responses during exercise at 20 degrees, 0 degrees and -20 degrees C.

This study was designed to clarify the effects of cold air exposure on metabolic and hormonal responses during progressive incremental exercise. Eight healthy males volunteered for the study. Informed consent was obtained from every participant. The following protocol was administered to each subject on three occasions in a climatic chamber in which the temperature was 20 degrees, 0 degree or -20 degrees C with relative humidity at 60% +/- 1%. Exercise tests were conducted on an electrically braked ergocycle, and consisted of a progressive incremental maximal exercise. Respiratory parameters were continuously monitored by an automated open-circuit sampling system. Exercise blood lactate (LA), free fatty acids (FFA), glucose levels, bicarbonate concentration (HCO-3), acid-base balance, plasma epinephrine (E) and norepinephrine (NE) were determined from venous blood samples obtained through an indwelling brachial catheter. Maximal oxygen uptake was significantly different between conditions: 72.0 +/- 5.4 ml kg-1 min-1 at 20 degrees C; 68.9 +/- 5.1 ml kg-1 min-1 at 0 degree C and 68.5 +/- 4.6 ml kg-1 min-1 at -20 degrees C. Workload, time to exhaustion, glucose levels and rectal temperature decreased significantly at -20 degrees C. Catecholamines and lactate values were not significantly altered by thermal conditions after maximal exercise but the catecholamines were decreased during rest. Bicarbonate, respiratory quotient, lactate and ventilatory thresholds increased significantly at -20 degrees C. The data support the contention that metabolic and hormonal responses following progressive incremental exercise are altered by cold exposure and they indicate a marked decrease in maximal oxygen uptake, time to exhaustion and workload.

Effects of selective cooling of the facial area on physiological and metabolic output during graded maximal or prolonged submaximal exercise.

Physiological and metabolic output responses to facial cooling during a graded maximal exercise and a prolonged submaximal exercise lasting 30 min at 65% VO2 max were investigated in five male subjects. Pedalling on a cycle ergometer was performed both with and without facial cooling (10 degrees C, 4.6 m s-1). Facial cooling at the end of graded maximal exercise apparently had no effect on plasma lactate (LA), maximal oxygen consumption (VO2 max), maximal heart rate (HR max), rectal temperature (Tre), work-load, lactate threshold (LT), ventilatory threshold (VT) and onset of blood lactate accumulation (OBLA). However, the response to facial cooling after prolonged submaximal exercise is significantly different for heart rate and work-load. The results suggest that facial wind stimulation during maximal exercise does not produce a stress high enough to alter the metabolic and physiological responses.

Decision making in sport: the effect of stimulus-response probability on the performance of a coincidence-anticipation task.

The purpose of the present study was to evaluate the quality of a motor response for different levels of expectancy and time constraint, in a two-choice coincidence-anticipation task. The probability of each of the two events likely to be presented were varied across different levels as well as the speed of the stimulus to be intercepted. The results indicated that neither the choice reaction time (CRT) and movement time, nor the performance of coincidence-anticipation were affected by the probability of the stimulus for the low and moderate stimulus speeds. However, when the stimulus traveled at a high speed a trade-off took place. The CRT decreased as the probability of the event increased, whilst the proportion of response initiation errors increased for the low probability events. This trade-off resulted in a better coincidence-anticipation as the probability of the event increased. The results obtained in the present experiment are clearly different from those obtained in a classic CRT-deadline paradigm, in that the trade-off observed between CRT and response initiation errors was far less pronounced in the coincidence-anticipation task. This difference was attributed to the higher negative consequences associated with a response initiation error in a coincidence-anticipation task. It is thus concluded that the tasks used to study the nature of the decision processes taking place in sports and sports-like situations must have some ecological validity to be of some help for the practitioner.

Extent and limits of cerebral adjustment to early section or congenital absence of the corpus callosum.

The ability to effect inter- and intrahemispheric comparisons of visual and tactile stimuli was studied in 4 callosotomized patients and 6 callosal agenesis subjects using response accuracy and response times to determine the extent of cerebral adjustment to functional or congenital absence of the corpus callosum. The visual tasks involved within- and between-fields presentation of pairs of colours and shapes. The tactile tasks required uni- and bimanual comparisons of 3 categories of stimuli (size, shape and texture) of increasing difficulty. Older callosotomized children showed disconnection deficits similar to those reported in adult split-brain patients, whereas both acallosal subjects and our youngest patient with complete callosal transection demonstrated a high level of accuracy in the interhemispheric tasks. However, all patients required considerably more time to accomplish the cross-integration of relatively complex visual and tactile information which seems to be one of the major limitations of the compensatory mechanisms. The results also indicate that the quality of transfer differs between the acallosal and early-callosotomized patients in relation to the sensory modality studied. Thus, visual cross-matching was found to be superior to bimanual matching for the callosotomized group, whereas intermanual comparisons proved to be more efficient than visual integration in the acallosals. These divergent findings suggest not only that different compensatory mechanisms may be operating in visual and tactile transfer, but also that the same mechanisms may be utilized differently by the two populations deprived of the use of callosal connections.

[Protection of the eyes in racket sports]. / La protection des yeux dans les sports de raquette.

A survey was conducted on 1032 racket sport players from 10 randomly selected racket sport centers in Quebec during the month of October 1985. The use of protective eye glasses was found to be higher in racketball (70.2%) and squash (45.8%) than in badminton (8.8%) or tennis (3.5%). While a little less than 60% of protective eye glasses were equipped with unbreakable lenses, 40% of protective glasses were simple eye guards, containing no lens at all. Hence a large number of players assumed that they had adequate protection while wearing simple eye guards or their everyday normal glasses. Gender differences did not seem to affect the use of protective eye glasses. A general observation was that the older the player the better the eye protection, whereas novice players tended to be less prepared to use the protective glasses. The use of protective eye glasses was found to be compulsory in close to 46% of racketball centers and in 25% of squash clubs.