Background: Bariatric surgery has a considerable effect on weight loss. A positive relation of exercise and weight loss has been described before. However, the mode of exercise and its timing pre- or postoperatively or a combination remains unclear. Methods: A multi-database search was conducted. Identified articles were reviewed on description of exercise, timing around a bariatric intervention, and outcome. Methodological quality of the included studies was rated using the Physiotherapy Evidence Database scale. A Cohen's kappa score assessed the level of agreement. Outcome measurements were improvement of anthropometric and physical fitness variables, operation related complications, weight regain, and quality of life. Results: A total of 8 prospective studies were included. Four focused on training before and 4 on training after a bariatric procedure. Details of exercises varied from 45 min treadmill up to full descriptive programs. Supervision was frequently included. Significant improvement was encountered for biometric results physical fitness variables. Conclusion: In the majority of reports on exercising in a (future) bariatric population, positive effects on anthropometrics, cardiovascular risk factors and physical fitness were described. However, the results were not unanimous, with a wide range of exercise programs and perioperative timing, therefore hampering adequate practical guidance.

Measurements of arterial blood gases are important in studies of ventilatory control during exercise and can give valuable information about the effi ciency of ventilation and gas exchange. To avoid the invasive procedure of placing arterial catheters for sampling arterial blood, partial pressure of end-tidal CO 2 (P etco 2 ) has been used as a noninvasive method to estimate Pa co 2 in young, healthy adults at rest and during exercise. [1][2][3][4] These studies have concluded that, although P etco 2 may slightly underestimate Pa co 2 at rest, P etco 2 is a good index of Pa co 2 during resting conditions. During exercise, the instantaneous P aco 2 fl uctuates cyclically with breathing, 5 and the P etco 2 is higher than the average P aco 2 over the complete breathing cycle. 6 Therefore, P etco 2 may overestimate Pa co 2 during exercise, when CO 2 production, ventilation, and tidal volume (V t ) are all increased. 7 To circumvent this problem, Jones et al 3 developed a regression equation to predict Pa co 2 from P etco 2 (P jco 2 ) and V t that corrects for the overestimation of Pa co 2 by P etco 2 :J 2 E T 2 T P CO 5.5 0.9 P CO 2.1 V (Equation 1) where V t is in liters.Background: Obesity affects lung function and gas exchange and imposes mechanical ventilatory limitations during exercise that could disrupt the predictability of Pa CO 2 from end-tidal P CO 2 (P ETCO 2 ), an important clinical tool for assessing gas exchange effi ciency during exercise testing. Pa CO 2 has been estimated during exercise with good accuracy in normal-weight individuals by using a correction equation developed by Jones and colleagues (P JCO 2 5 5.5 1 0.9 3 P ETCO 2 -2.1 3 tidal volume). The purpose of this project was to determine the accuracy of Pa CO 2 estimations from P ETCO 2 and P JCO 2 values at rest and at submaximal and peak exercise in morbidly obese adults. Methods: Pa CO 2 and P ETCO 2 values from 37 obese adults (22 women, 15 men; age, 39 Ϯ 9 y; BMI, 49 Ϯ 7; [mean Ϯ SD]) were evaluated. Subjects underwent ramped cardiopulmonary exercise testing to volitional exhaustion. P ETCO 2 was determined from expired gases simultaneously with temperature-corrected arterial blood gases (radial arterial catheter) at rest, every minute during exercise, and at peak exercise. Data were analyzed using paired t tests. Results: P ETCO 2 was not signifi cantly different from Pa CO 2 at rest (P ETCO 2 5 37 Ϯ 3 mm Hg vs Pa CO 2 5 38 Ϯ 3 mm Hg, P 5 .14). However, during exercise, P ETCO 2 was signifi cantly higher than Pa CO 2 (submaximal: 42 Ϯ 4 vs 40 Ϯ 3, P , .001; peak: 40 Ϯ 4 vs 37 Ϯ 4, P , .001, respectively). Jones' equation successfully corrected P ETCO 2 , such that P JCO 2 was not signifi cantly different from Pa CO 2 (submax: P JCO 2 5 40 Ϯ 3, P 5 .650; peak: 37 Ϯ 4, P 5 .065). Conclusion: P JCO 2 provides a better estimate of Pa CO 2 than P ETCO 2 during submaximal exercise and at peak exercise, whereas at rest both yield reasonable estimates in morbidly obese individuals. Clinicians and physiologists can obtain accurate estimations ...