Gender Differences in Energy Expenditure During Walking With Backpack and Double-Pack Loads

Cardiorespiratory responses: Pilates compared to different walking speeds in healthy adults

BACKGROUND

The impact of a single-session Pilates exercise on cardiorespiratory fitness and metabolic parameters is still uncertain.

AIMS

The aim of this study was to examine the cardiorespiratory changes during a single-session Pilates exercise and compare cardiorespiratory fitness-related parameters with walking at different speeds on a treadmill, at low (3.2 kph) and moderate intensities (4.8 kph).

METHODS

Cardiorespiratory responses were measured with a cardiopulmonary exercise test device in 31 healthy young adults at rest, during a single Pilates session, walking at 3.2 kph and walking at 4.8 kph. The study design employed a cross-over design. Participants were randomly assigned to two experimental groups: a Pilates training session following treadmill walking or treadmill walking following a Pilates training session.

RESULTS

Mean MET, oxygen and energy consumption during Pilates were similar to walking at 3.2 kph (p > 0.05), but significantly lower than walking at 4.8 kph (p < 0.05). The mean heart rate during Pilates was higher than walking at 3.2 kph (p < 0.05), but similar to walking at 4.8 kph (p > 0.05). Significantly higher carbohydrate metabolism was used during Pilates compared to walking (p < 0.05).

CONCLUSION

The cardiopulmonary responses to a single Pilates session are similar to walking at a speed of 3.2 kph but lower than walking at 4.8 kph. These results indicate that while Pilates may not generate sufficient cardiopulmonary changes to enhance cardiorespiratory fitness as a moderate-intensity exercise in healthy young adults, it may still offer other benefits such as improvements in flexibility, core strength, and posture.

A systematic review of the physiological and biomechanical differences between males and females in response to load carriage during walking activities

The purpose of this review was to systematically assess literature on differences between males and females in the physiological and biomechanical responses to load carriage during walking. PubMed, CINAHL, Scopus, Web of Science and the Cochrane library were searched. A total of 4637 records were identified and screened. Thirty-three papers were included in the review. Participant characteristics, load carriage conditions, study protocol, outcome measures and main findings were extracted and qualitatively synthesised. Absolute oxygen uptake and minute ventilation were consistently greater in males but there were limited sex-specific differences when these were expressed relative to physical characteristics. There is limited evidence of sex-specific differences in spatio-temporal variables, ground reaction forces (normalised to body mass) or sagittal plane joint angles with load. However, differences have been found in hip and pelvic motions in the frontal and horizontal planes, which might partly explain an economical advantage for females proposed by some authors.

Males Have a Higher Energy Expenditure than Females during Squat Training

The main objective of this study was to determine the differences in energy expenditure (EE) according to sex during and after two different squat training protocols in a group of healthy young adults. Twenty-nine Sports Sciences students volunteered to participate in this study. They attended the laboratory on four different days and completed four sessions: two sessions with 3 sets of 12 repetitions at 75% of their one-repetition maximum (RM) and two sessions with 3 sets of 30 repetitions at 50% of their 1RM. Energy expenditure was evaluated using an indirect calorimeter. Males consistently demonstrated higher EE in all sessions and intensities. The linear regression model identified a significant association between sex, BMI, and total EE across all sessions and intensities. In conclusion, males exhibited higher EE in both protocols (50% and 75% of 1RM) throughout all sessions. Furthermore, sex and BMI were found to influence EE in healthy young adults. Therefore, coaches should consider sex when assessing EE, as the metabolic response differs between males and females.

The effect of clinically elevated body mass index on physiological stress during manual lifting activities

Individuals with a body mass index (BMI) classified as obesity constitute 27.7% of U.S. workers. These individuals are more likely to experience work-related injuries. However, ergonomists still design work tasks based on the general population and normal body weight. This is particularly true for manual lifting tasks and the calculation of recommended weight limits (RWL) as per National Institute of Occupational Safety & Health (NIOSH) guidelines. This study investigates the effects of BMI on indicators of physiological stress. It was hypothesized that, for clinically elevated BMI individuals, repeated manual lifting at RWL would produce physiological stress above safety limits. A repetitive box lifting task was designed to measure metabolic parameters: volume of carbon dioxide (VCO2) and oxygen (VO2), respiratory exchange ratio (RER), heart rate (HR), and energy expenditure rate (EER). A two-way ANOVA compared metabolic variables with BMI classification and gender, and linear regressions investigated BMI correlations. Results showed that BMI classification represented a significant effect for four parameters: VCO2 (p < 0.001), VO2 (p < 0.001), HR (p = 0.012), and EER (p < 0.001). In contrast, gender only had a significant effect on VO2 (p = 0.014) and EER (p = 0.017). Furthermore, significant positive relationships were found between BMI and VCO2 (R2 = 59.65%, p < 0.001), VO2 (R2 = 45.01%, p < 0.001), HR (R2 = 21.86%, p = 0.009), and EER (R2 = 50.83%, p < 0.001). Importantly, 80% of obese subjects exceeded the EER safety limit of 4.7 kcal/min indicated by NIOSH. Indicators of physiological stress are increased in clinically elevated BMI groups and appear capable of putting these individuals at increased risk for workplace injury.

Epidemiological characteristics of different patterns of obesity among adults in rural communities of south-east Nigeria: a population-based cross-sectional study

Background

Obesity is a complex disease characterised by excess fat accumulation and health risks. There is paucity of data on epidemiology of obesity patterns among adults in rural Nigeria. This study aimed to provide current data on the prevalence and predictors of three patterns of obesity (abdominal obesity alone, general obesity alone and a combination of both) among adults in three rural communities of Enugu State, South-east Nigeria to enhance specific obesity prevention and control programmes/interventions.

Methods

This population-based cross-sectional study involved 500 adults selected through a six-stage random sampling technique. Questionnaire was used to obtain data on socio-economic, dietary and lifestyle characteristics of the respondents. Weight, height and waist circumference were measured by standard procedures. Body mass index was used to assess general obesity while abdominal obesity was assessed through waist circumference. Each respondent was classified under only one of the three patterns: general obesity alone, abdominal obesity alone and combined obesity. Binary and multivariate logistic regression analyses were used to assess the predictors. Significance was set P<0.05.

Results

Prevalence of abdominal obesity alone was 6.0%. General obesity alone was found among 31.4% and 45.6% were affected by combined obesity. Being a female (AOR:0.35, 95% C.I.: 0.14, 0.88) and not skipping meals (AOR:0.24, 95% C.I.: 0.10, 0.55) were associated with less likelihood of abdominal obesity but ≥3 times daily meal intake increased the risk by 2.52 (AOR:2.52, 95% C.I.:1.10, 5.75). Predictors of general obesity alone were age 41-60 years (AOR:1.84, 95% C.I.:1.14, 2.97), being a female (AOR:7.65, 95% C.I.:4.77, 12.26) and having any form of formal education (AOR:2.55, 95% C.I.:1.10, 5.91). Combined obesity was less likely among 41-60 year-olds (AOR:0.36, 95% C.I.:0.23, 0.56) and females (AOR:0.21, 95% C.I.:0.13, 0.32). Never married (AOR:1.94, 95% C.I.:1.03, 3.67) and vigorous physical activities (AOR:1.81, 95% C.I.:1.08, 3.02) increased the risk of combined obesity by almost 2.

Conclusions

Prevalence of abdominal obesity alone, general obesity alone and combined obesity were high. They were functions of age, sex, never married, having any form of formal education, skipping meals, ≥3 daily meal intake and self-reported vigorous physical activity. Focused nutrition and health education are recommended strategies for prevention and control of obesity.

Impact of Backpacks on Ergonomics: Biomechanical and Physiological Effects: A Narrative Review

(1) Background: the effects of load carriage packs on human gait biomechanics, physiology and metabolism depend on the weight carried, the design of the pack and its interaction with the user. (2) Methods: An extensive search in the PubMed database was performed to find all the relevant articles using the following keywords: backpack, rucksack, backpack ergonomy and sports backpack; 60 articles were included. (3) Results and significance: Double pack (DP) and T-pack (TP) designs are recommended solutions for school children, compared with backpacks (BP). For soldiers and hikers, a backpack remains the best compromise. A hip belt is recommended for BPs as well as for the back of DPs. Shorter and stiffer shoulder straps combined with a higher and tighter load placement on the back provide the best combination in terms of balance, muscle activation and energy expenditure. It is, therefore, possible to determine guidelines for designing the optimal load carriage system, depending on the application. (4) Conclusions: based on the available evidence, DP and TP are advantageous in terms of posture. DP is better than conventional BPs in terms of balance and muscle activation, but has the disadvantage of limited visibility, thermal sensation and obstructed ventilation. In general, it is desirable not to exceed 40% of body mass (BM).

Effects of gradient and age on energy expenditure and fat metabolism during aerobic exercise at equal intensity in women

[Purpose]

This study aimed to investigate the effects of gradient and age on energy expenditure and fat metabolism during aerobic exercise at equal intensity in women.

[Methods]

Thirty women in their twenties (n=15) and fifties (n=15) were enrolled. All subjects performed aerobic exercise on a treadmill for 10 min at 0% and 6% gradient repeatedly to elicit 50%, 60%, and 70% VO₂max.

[Results]

Energy expenditure and fat oxidation were higher during aerobic exercise at 6% of the gradient than at 0%, and there was no significant difference in carbohydrate oxidation in any age group.

[Conclusion]

Aerobic exercise at a 6% gradient was more favorable for fat oxidation than a 0% gradient in all age groups. In particular, in the case of women in their fifties, walking on a gradient of 6%, which is favorable for increasing fat oxidation, was more effective than walking on flat ground for preventing and reducing obesity. However, to examine the difference in fat oxidation among exercise intensities more accurately, exercise performed for longer than 30 min is required. Follow-up studies are required to investigate the effect of various gradients on physiological and metabolic characteristics when carrying out aerobic exercises for more than 30 min.

Graded exercise test with or without load carriage similarly measures maximal oxygen uptake in young males and females

The aim of this was to compare the effects of the graded exercise test (GXT) with or without load carriage on maximal oxygen uptake ([Formula: see text]) heart rate (HR), and expired ventilation ([Formula: see text]) and blood lactate in young healthy males and females. The study included ten females (age:20.2±0.7 yrs) and ten males (age:19.5±0.7 yrs) who performed the modified Bruce protocol at five load conditions; unloaded, 5, 10, 15, and 20% of body weight (BW) (kg). All the tests were performed in random order, at least 48 hours apart. During the GXTs, HR, [Formula: see text], [Formula: see text], workload and test duration were recorded and blood lactate concentration was measured before and immediately after the GXTs. [Formula: see text] remained unchanged during the GXTs in load and unloaded conditions for both sexes (p>0.05). Test duration was significantly less in females during the GXT with 15% BW (15.9±0.51 min vs. 18.1±1.14 min; p = 0.014) and 20% BW load carriage (15.2±0.75 min vs. 18.1±1.14 min; p = 0.020), compared to the unloaded GXT. Males showed significant decrease in the test duration during the GXT with load 15% BW (20.5±0.53 min vs. 22.8±0.61 min; p = 0.047) and with 20% BW (19.6±0.42 min vs. 22.8±0.71 min; p = 0.004), compared to the GXT with 5% BW. [Formula: see text] statistically decreased in female subjects only at 15% BW compared to 20% BW (15% BW = 77.9 ± 10.5 L/min vs. 15% BW = 72.0 ± 10.9 L/min; p = 0.045). There was no difference observed in maximal HR and blood lactate concentration between the GXTs in load and unloaded conditions. This study indicates that no matter the load % used during the GXT, [Formula: see text], but not total exercise time, remains the same in young males and females.

The effects of a loaded rucksack and weighted vest on metabolic cost and stride frequency in female adults

This study evaluated the metabolic cost and stride frequency during exercise while wearing an evenly distributed weight vest in recreationally fit women. Nine healthy women performed a modified Balke treadmill test until volitional fatigue in one of three conditions; (1) unloaded (2) rucksack and (3) weighted vest. Wearing a weighted vest did not show improvement of V̇_O2peak, HR_peak, peak stride frequency or average stride frequency (all p ≥ 0.05). However, total time of exercise was significantly longer in the evenly distributed weight vest condition compared to the rucksack condition (p = 0.024) despite similar V̇_O2peak and HR_peak. These results may provide practical information when females in tactical populations are preparing for missions in which heavy loads must be carried. Practitioner summary: This study compared the effects of load carriage mode on metabolic cost and stride frequency during graded exercise in females. The weighted vest showed significantly longer exercise time despite similar V̇_O2peak and HR_peak. Development of standardised weight distribution mode may serve as an advantageous strategy for females in tactical settings. Abbreviations: HR: heart rate; V̇O2: oxygen uptake; RPE: rating of perceived exertion; V̇O2peak: peak oxygen uptake; HRpeak: peak heart rate.