A 45-Minute Vigorous Exercise Bout Increases Metabolic Rate for 14 Hours – Research Review

Knab AM et. al. A 45-Minute Vigorous Exercise Bout Increases Metabolic Rate for 14 Hours.  Med Sci Sports Exerc. 2011 Feb 8. [Epub ahead of print]

INTRODUCTION: The magnitude and duration of the elevation in resting energy expenditure following vigorous exercise have not been measured in a metabolic chamber. This study investigated the effects of inserting a 45-min vigorous cycling bout into the daily schedule versus a controlled resting day on 24-h energy expenditure in a metabolic chamber.
METHODS: Ten male subjects (ages 22 to 33 yrs) completed two separate 24-h chamber visits (one rest and one exercise day) and energy balance was maintained for each visit condition. On the exercise day, subjects completed 45-min of cycling at 57% Wattsmax (mean±SD, 72.8±5.8% VO2max) starting at 11:00 am. Activities of daily living were tightly controlled to ensure uniformity on both rest and exercise days. The area under the energy expenditure curve for exercise and rest days was calculated using the trapezoid rule in the EXPAND procedure in the Statistical Analysis Systems (SAS) and then contrasted.
RESULTS: The 45-min exercise bout resulted in a net energy expenditure of 519±60.9 kcal (P<0.001). For 14-h post-exercise, energy expenditure was increased 190±71.4 kcal compared to the rest day (P±0.001).
CONCLUSION: In young male subjects, vigorous exercise for 45-min resulted in a significant elevation in post-exercise energy expenditure that persisted for 14-h. The 190 kcals expended post-exercise above resting levels, represented an additional 37% to the net energy expended during the 45-min cycling bout. The magnitude and duration of increased energy expenditure following a 45-min bout of vigorous exercise may have implications for weight loss and management.

In recent years there has been a focus on the calorie burn that occurs after training, referred to in science terms as EPOC (Excess Post-exercise Oxygen Consumption).  A variety of different types of training (usually revolving around brief duration, high-intensity methods such as interval training or circuits) have been proposed with the major effect of such activity being in the EPOC that is created.


Normal Weight Men and Women Overestimate Energy Expenditure – Research Review

Willbond SM et. al. Normal weight men and women overestimate exercise energy expenditure.  J Sports Med Phys Fitness. (2010) 50(4):377-84.

AIM: The limited potential of exercise to induce weight loss could be partly due to the overestimation of the energy cost of exercise. The objectives of this study were twofold: 1) to investigate whether men and women are able to accurately estimate exercise energy expenditure (EE); and 2) to determine whether they have the ability to accurately compensate for the EE of exercise during a buffet-type meal.
METHODS: Sixteen (8 men, 8 women) moderately active (VO2 peak=45.4±7.7 mL.kg-1.min-1), normal weight (BMI=22.8±3.3 kg/m2) individuals, aged 20-35 years, were studied. They were blinded to two randomly assigned experimental conditions: a 200 and a 300 kcal (measured by indirect calorimetry) exercise sessions that were performed on a treadmill at the same intensity (50% of VO2 peak). At the end of each exercise session individuals were asked to estimate EE of the exercise sessions and to then eat the caloric equivalent of their estimated exercise EE from a buffet-type meal.
RESULTS: Estimated EE was higher than measured EE for both the 200 kcal (825.0±1061.8 vs. 200.1±0.7 kcal, P<0.05) and 300 kcal (896.9±952.4 vs. 300.2±0.7 kcal, P<0.05) sessions. Further, post-exercise energy intake was higher than measured EE for the 200 kcal (556.8±204.4 vs. 200.1±0.7 kcal, P<0.001) and the 300 kcal (607.2±166.5 vs. 300.2±0.7 kcal, P<0.001) sessions. Although post-exercise energy intake was lower than estimated EE, no significant differences were noted.
CONCLUSION: These results suggest that normal weight individuals overestimate EE during exercise by 3-4 folds. Further, when asked to precisely compensate for exercise EE with food intake, the resulting energy intake is still 2 to 3 folds greater than the measured EE of exercise.


Low Fat Loss Response After Medium-Term Supervised Exercise in Obese is Associated with Exercise-Induced Increase in Food Reward – Research Review

Finlayson G et. ao. Low fat loss response after medium-term supervised exercise in obese is associated with exercise-induced increase in food reward.  J Obes. (2011);2011. pii: 615624. Epub 2010 Sep 20.

Objective. To examine exercise-induced changes in the reward value of food during medium-term supervised exercise in obese individuals. Subjects/Methods. The study was a 12-week supervised exercise intervention prescribed to expend 500 kcal/day, 5 d/week. 34 sedentary obese males and females were identified as responders (R) or non-responders (NR) to the intervention according to changes in body composition relative to measured energy expended during exercise. Food reward (ratings of liking and wanting, and relative preference by forced choice pairs) for an array of food images was assessed before and after an acute exercise bout. Results. 20 responders and 14 non-responders were identified. R lost 5.2 kg ± 2.4 of total fat mass and NR lost 1.7 kg ± 1.4. After acute exercise, liking for all foods increased in NR compared to no change in R. Furthermore, NR showed an increase in wanting and relative preference for high-fat sweet foods. These differences were independent of 12-weeks regular exercise and weight loss. Conclusion. Individuals who showed an immediate post-exercise increase in liking and increased wanting and preference for high-fat sweet foods displayed a smaller reduction in fat mass with exercise. For some individuals, exercise increases the reward value of food and diminishes the impact of exercise on fat loss.


It seems like I haven’t done a research review in forever, probably because I haven’t done a research review in forever.  But since I’m holding off on my little surprise until next week, this seemed as good a time as any.  Today’s paper is also something that is rather important in the overall scheme for folks seeking weight/fat loss.


Role of Nonexercise Activity Thermogenesis in Resistance to Fat Gain in Humans – Research Review

Levine JA et. al. Role of nonexercise activity thermogenesis in resistance to fat gain in humans.  Science. (1999) Jan 8;283(5399):212-4.

Humans show considerable interindividual variation in susceptibility to weight gain in response to overeating. The physiological basis of this variation was investigated by measuring changes in energy storage and expenditure in 16 nonobese volunteers who were fed 1000 kilocalories per day in excess of weight-maintenance requirements for 8 weeks. Two-thirds of the increases in total daily energy expenditure was due to increased nonexercise activity thermogenesis (NEAT), which is associated with fidgeting, maintenance of posture, and other physical activities of daily life. Changes in NEAT accounted for the 10-fold differences in fat storage that occurred and directly predicted resistance to fat gain with overfeeding (correlation coefficient = 0.77, probability < 0.001). These results suggest that as humans overeat, activation of NEAT dissipates excess energy to preserve leanness and that failure to activate NEAT may result in ready fat gain.


There has long been a question of why some people seem to be able to ‘eat anything they want’ and remain thin while others can do no such thing; in fact this is often used as an argument that The Energy Balance Equation is wrong.

More in fact, the paper I’m going to talk about today was once trotted out by several individuals as ‘proof’ that The Energy Balance Equation was incorrect.  Unfortunately all their discussion really ended up proving was that, as I suggest in The Energy Balance Equation, the issue was not the equation, but that they had no clue what they were talking about.  But I’m getting ahead of myself.

Certainly we all have seen, known (or in lucky situations been) that person who seems to ‘eat anything they want’ without gaining appreciable weight.  This is in contrast to those people who seem to be able to simply look at food and get fat. What’s going on?


Obesity and Physical Inactivity: The Relevance of Reconsidering the Notion of Sedentariness

So, having already made one change to the structure of the research review and looking at more than paper at a time, I’ve decided that that approach is confusing, it also makes the titles and permalinks screwy which, as any good Internet marketer knows, is bad for SEO.  So moving forwards, I’m going to go back to only looking at a single study at a time (but still in less detail) but do them more often.


Chaput JP, Tremblay A. Obesity and Physical Inactivity: The Relevance of Reconsidering the Notion of Sedentariness. Obes Facts. (2009)2(4):249-254.

The population statistics of most countries of the world are indicating that industrialization and computerization have been associated with an increase in sedentariness and more recently with a significant shift from healthy weight to overweight. In general, this change in the overweight/obesity prevalence is attributed by health professionals to suboptimal diet and physical activity practices. However, recent data raised the possibility that excess weight gain might also be the outcome of changes imposed by our ’24-hour’, hectic lifestyle. Parallel to an increase in body weight, one has observed a reduction in sleep time and an increase in knowledge-based work (KBW) that appear as a growing necessity in a context of economic competitiveness and globalization. Sleep and cognitive work both exert a trivial effect on energy expenditure and may thus be considered as sedentary activities. However, their respective effect on energy intake is opposite. Indeed, an increase in the practice of the most sedentary activity, i.e. sleep, is associated with a hormonal profile facilitating appetite control whereas KBW appears as a stimulus favoring a significant enhancing effect on food intake. Television viewing is another example of sedentary activity that has been shown to increase the intake of high-density foods. These observations demonstrate that the modern way of living has favored a change in human activities whose impact goes well beyond what has traditionally been attributed to a lack of physical exercise. Therefore, we will need to reconsider the notion of ‘sedentariness’ which includes several activities having opposing effects on energy balance.