Spontaneous activity responses to exercise in males and females

Abstract

Objective: This study examines the impact of a short-term exercise programme, prescribed on the basis of current exercise recommendations, on energy balance in males and females to assess whether this type of exercise induces compensatory changes in spontaneous activity energy expenditure (SAEE) and energy intake (EI). Design: Individuals were monitored for 16 days, 8 days of habitual physical activity (C) and 8 days when exercise was imposed (E). Total energy expenditure (TEE) was calculated from individual relationships of V O 2 and V CO 2 to heart rate (HR) records of HR and physical activity obtained during waking hours of the C and E periods and basal metabolic rate (BMR) measurements (Deltatrac System, Datex Instrumentation). Changes in nude body mass (BM) were estimated by using a digital scale (Sartorius AG, Gottigen, Germany). Setting: Laboratory and free-living. Subjects: Eight lean females (body fat: 17.574.5%) and eight males of similar percentage body fat participated in this study. All subjects were Caucasian and aged between 20 and 25 years. Intervention: During the E period, a supervised exercise session was conducted every second day, each consisting of a total net energy expenditure of 2092 kJ þ BMR at 90% lactate threshold. Results: During the E period, TEE was higher than C in males and females (exercise: 95.2713.9, 78.3715.9 MJ; control: 82.4710.4, 68.8716.7 MJ, respectively; Po0.00; P ¼ 0.02). SAEE, calculated as TEE minus the energy expended during exercise, was not significantly different between C (males: 82.474.8 MJ; females: 68.877.6 MJ) and E (males: 86.876.3 MJ; females: 70.077.2 MJ) periods in either gender. Males showed no change in BM over the C (pre-intervention: 83.477.2 kg; post-intervention: 83.176.8 kg) or E (pre-intervention: 83.476.8 kg; post-intervention: 83.476.8 kg) periods. Females' BM over the C period did not alter (pre-intervention: 63.372.8 kg; post-intervention 63.773.1 kg); however, there was a significant decrease (Po0.00) in BM over the E period (pre-intervention: 63.072.7 kg; post-intervention: 62.472.7 kg). Conclusion: The exercise programme was achieved in males and females without any impact on SAEE. Therefore, differences between genders in relation to BM reduction can be explained by differences in the EI response to exercise.

Behavioral Compensatory Adjustments to Exercise Training in Overweight Women

“…Such increases in TEE should aid body fat and body weight loss, provided all other variables affecting energy balance are kept constant. However, exerciseinduced perturbations to energy balance may initiate behavioural compensatory adjustments and either alter food intake (24,27,33,34,36) or cause a reduction in normal daily activities (11,16,21,36). This compensation for the exercise-induced energy deficit may explain why exercise alone often does not result in successful weight loss in obese and overweight individuals (12).…”

Body Composition And Physical Activity Maintenance One Year After A 12-week Exercise Intervention In Women

“…The authors stated that the fact that women lost weight during the exercise phase suggests that women also did not increase EI in response to increased EE whereas males who had no weight loss may have increased EI to offset the negative energy balance imposed by increased EE. However, the authors did note that the negative energy balance experienced by the women may not have persisted long enough in the eight day experimental period to induce adaptive compensatory mechanisms increasing EI, as a number of other studies have found that lean women do increase EI in response to long term negative energy balance (McLaughlin et al, 2006).…”

“…Multiple studies have examined the relationship between behavioral and physiological mechanisms and compensation (Church et. Al, 2009;Hollowell et al, 2009;King et al, 2007b;Manthou, Gill, Wright, & Malkova, 2010;McLaughlin, Malkova, &Nimmo, 2006;R. Stubbs et al, 2002;Westerterp, Meijer, Janssen, Saris, & Ten Hoor 1992;Woo, Garrow, and Pi-Sunyer, 1982;Woo and Pi-Sunyer, 1985), and doses of exercise which may cause induce a greater magnitude and prevalence of compensation (Church et al 2009;Hollowell et al, 2009;R.…”

“…They were between 20 and 25 years old and were considered lean, having body fat percentages of 17 ±4.5%. Subjects were not informed that EI was an outcome measure of the study in order to prevent bias in their eating patterns (McLaughlin et al, 2006).…”

“…The length of exercise sessions was adjusted to burn 2092kJ plus BMR per session. During the control phase and the non-exercising portions of the exercise phase total EE was calculated from entries in the PA journal and EE values which were determined for each individual for a variety of activities prior to the start of the intervention (McLaughlin et al, 2006).…”