Weight Loss

Weight Loss Surgery: Considerations for the Fitness Professional

Nicole Golden
Nicole Golden

Weight loss surgery is a common phenomenon, so it's important to be informed about what gastric bypass surgery - and other similar bariatiric procedures - entail for your personal training practice.

If you are a weight loss specialist, a personal trainer, or a nutrition coach, you will want to equip yourself with as much bariatric knowledge as you can to best serve your clients who have undergone weight loss surgery. 

Let's dive into the research!

how common is weight loss surgery?

Obesity is a condition that affects 42.7% of Americans with severe obesity (BMI greater than 40 kg/m2) affecting 9.2% of the population (Defining Adult Overweight and Obesity, 2019). The number of people worldwide continues to climb despite the plethora of diet and fitness programs available.

The American Society for Metabolic and Bariatric Surgery (2020) indicates that a patient is eligible for gastric bypass surgery if their BMI is over 40 kg/m2 (or they are 100 lbs or more overweight) and have been unsuccessful at attaining a healthy weight despite numerous attempts.

A patient will be considered for bariatric surgery if they have a BMI over 35 kg/m2 and have a co-morbidity such as hypertension and diabetes (ASMBS, 2019).

Personal trainers are often responsible for creating and implementing a safe and effective exercise program for bariatric patients. This type of client poses many challenges for their fitness professional which must be considered. Therefore, needs assessments and data tracking are vital for their success at attaining a healthy lifestyle and maintaining a healthy weight long-term.

Physiology of Weight Loss: after Gastric Bypass Surgery

Although there are several types of weight loss surgery, the focus of this discussion is the full Roux-en-Y procedure. A surgeon will excise a small portion of the stomach to create a pouch approximately the size of a walnut and attach it directly to the middle portion of the small intestine thereby bypassing a large portion of nutrient absorption.

The procedure should theoretically restrict the total number of calories that can be consumed and cause malabsorption as the primary mechanism of weight loss, however, there are other metabolic factors that aid in a

bariatric patients’ weight loss related to other factors (hormonal, psychological and physiologic) that have not been fully elucidated (Park & Torquati, 2011).

Needs Assessments for a Gastric Bypass Patient

Exercise is an important part of recovery from a Roux-en-Y procedure as it aids in metabolic improvements and in preserving lean body mass. Likewise, many of these individuals have lived a sedentary lifestyle which increases their likelihood or exacerbates their symptoms of hypertension, dyslipidemia, poor overall cardiac function, poor movement leading to orthopedic issues and diabetes.

A regular exercise program can help the patient continue to make improvements in these areas. However, maintaining a regular exercise routine post-surgery is difficult for many patients who have undergone a gastric bypass procedure (Coen & Goodpaster, 2016).

Surgical Considerations

A Roux-en-Y procedure is a major surgical procedure. It is important for the fitness professional to be aware of this, especially when designing core training programs due to the risk of hernia and diastasis recti (Stegen et al., 2009). Clearance for exercise from the patient’s surgeon is critical. Additionally, the client should fill out a Physical Activity Readiness Questionnaire PAR-Q assessment form to document any co-morbidities which may affect exercise programming such as hypertension, diabetes (skin breakdown, poor circulation) and poor cardiac function (Clark et al., 2014).

Movement Assessments

Movement dysfunction is quite common in this population for several reasons. First, many of these clients spend a large portion of their day in a seated position in addition to the

mechanical weight load due to the presence of pannus in most cases. Tendinopathy due to weight overload, degeneration of the tendons and movement dysfunctions is also a common finding (Fairley et al., 2013).

The Overhead Squat Assessment (OHSA) can be helpful in determining the specific faulty patterns the client displays and aid the fitness professional in creating an effective training program for the client. Common muscle imbalance patterns seen in these clients, in the lower body, involve significant underactivity of the gluteus medius/maximus, intrinsic core stabilizers and anterior tibialis and hamstring complex.

Likewise, overactivity is often seen in the adductors, calves and hip flexor complex. Common imbalances in the upper body include overactivity in the latissimus dorsi/teres major and pectoralis major/minor, upper trapezius and relatively underactivity in the external rotators (i.e., supraspinatus, teres minor and infraspinatus) as well as mid/lower trapezius, cervical flexors and rhomboids (Clark et al, 2014).

Push up assessments and some other assessments of muscle endurance are often inappropriate in these clients due to the presence of co-morbidities (i.e., diabetes, cardiac dysfunction). Targeted flexibility assessments may also be a challenge due to the client’s fat mass. Similarly, one rep maximum assessment may also cause cardiac strain and are oftentimes contraindicated in gastric bypass patients (Stegen et al., 2009).

Many gastric bypass patients will present with a history of inactivity and hence poor muscle endurance. The client’s improvements can be tracked through the process of how they are able to complete their training programs. Training appropriate movement patterns is more critical at this stage than improving strength or endurance (Clark et al., 2014). The OHSA can be repeated at monthly intervals to screen for improvements in faulty movement patterns and to assess the client’s readiness to move onto more advanced stability and/or strength training.

Body Composition Assessments

Bioimpedance testing (BIA) via Inbody technology can be an accurate way to measure both fat and lean body mass losses post gastric-bypass surgery. BIA is important as malnutrition is a piece of the sequelae post Roux-en-Y which can lead to loss of muscle as well as fat. Strength training and adequate protein intake can offset some of the losses of muscle tissue. A baseline BIA reading with monthly readings to follow is recommended to track weight loss progress as well as to monitor levels of muscle tissue (de Freitas Junior et al., 2014).

Cardio-respiratory Assessment

Cardio-respiratory testing is an important measure for tracking the progress of a client who has undergone gastric bypass. The YMCA 3-minute step test and 6-minute walk test are both validated measures for approximating VO2 max individuals with severe obesity. However, the YMCA 3-minute step test requires less equipment and less time to perform and may be favored over the alternative in fitness center settings. The test should be repeated every 6-8 weeks to track the client’s progress towards healthier functioning of the circulatory system (Hong et al., 2019).

Nutritional/Hydration Considerations

Surgery such as the Roux-en-Y procedure that lead to malabsorption have many nutritional consequences that can affect exercise performance. Protein deficiency as well as deficiency in iron, folate, vitamin D, calcium, thiamin and vitamin B12 are commonly seen in these patients.

Additionally, dumping syndrome can occur if the patient consumes carbohydrate in normal volumes causing severe gastrointestinal distress, vomiting and diarrhea. Hydration is also a complication of the procedure as the stomach is unable to hold enough liquids to prevent dehydration in the first year following surgery until the stomach remnant (pouch) stretches and increases in volume (Sherf Dagan et al., 2017).

These deficiencies can pose a challenge for the fitness professional designing exercise programs for this type of client. Low iron levels can impair oxygen carrying capacity and gas exchange leading to poor cardio-respiratory endurance. Likewise, protein malabsorption and vitamin B12 deficiency can decrease muscle synthesis after strength training. Insufficient calcium can cause problems with muscle contractions.

Dehydration can impair the body’s cooling systems, decrease blood plasma volume and make endurance activities very difficult as can glycogen depletion from the lack of carbohydrates in the diet (Lukaski, 2004).

The trainer must progress the client slowly through different phases of training. The fitness professional must work closely with the patient’s physician and nutritionist (who should be closely following the patient) to ensure that nutritional and hydration considerations are mitigated, and appropriate screenings are completed.

Strategies such as vitamin supplementation, frequent drinking of water during exercise and throughout the day (many hydration solutions can lead to dumping syndrome and should be avoided), timing carbohydrate intake around exercise and timing protein intake after exercise are strategies that can help a bariatric patient succeed with an exercise program despite nutritional challenges (Petering & Webb, 2009).

Psychological Considerations

Exercise is often a novel lifestyle change for many gastric bypass patients though it is highly recommended. Exercise compliance can prove difficult for this type of client under many circumstances.

A readiness for change screening is recommended as an assessment for these clients to determine their motivation to engage in exercise and change their behaviors. Thisassessment can be done in conjunction with the client’s psychologist (as part of their bariatric surgery team) or in the fitness center setting. Follow-up screenings are recommended every 1-2 months to continue to assess the client’s overall motivation (Stegen et al., 2009).

For more information on how you should approach training for post-surgery clients, check out this highly informational talk on the subject. 


The post-gastric bypass patient poses special challenges for the fitness professional responsible for their exercise programming. However, with appropriate assessments, regular re-assessment and close follow-up with the client’s medical team, they can be highly successful with long-term lifestyle changes.


ASMBS. (2019). Who is a Candidate for Bariatric Surgery? | Patients | ASMBS. American Society for Metabolic and Bariatric Surgery. https://asmbs.org/patients/who-is-a-candidate-for-bariatric-surgery

Clark, M. A., Lucett, S. C., Mcgill, E., Montel, I., Sutton, B., & Sports, O. (2014). NASM essentials of corrective exercise training. Burlington Jones & Bartlett Learning.

Coen, P. M., & Goodpaster, B. H. (2016). A role for exercise after bariatric surgery? Diabetes, Obesity & Metabolism, 18(1), 16–23. https://doi.org/10.1111/dom.12545

de Freitas Junior, W. R., Ilias, E. J., Kassab, P., Cordts, R., Porto, P. G., Martins Rodrigues, F. C., Ali Taha, M. I., Carrara, P., de Carvalho Aguiar, I., de Oliveira, L. V. F., Castro, O., & Malheiros, C. A. (2014). Assessment of the body composition and the loss of fat-free mass through bioelectric impedance analysis in patients who underwent open gastric bypass. The Scientific World Journal, 2014. https://doi.org/10.1155/2014/843253

Defining adult overweight and obesity. (2019). Centers for Disease Control and Prevention. https://www.cdc.gov/obesity/adult/defining.html

Fairley, J., Toppi, J., Cicuttini, F. M., Wluka, A. E., Giles, G. G., Cook, J., O’Sullivan, R., & Wang, Y. (2013). Obesity is a risk factor for patellar tendinopathy in middle-aged adults without clinical knee osteoarthritis. Obesity Research & Clinical Practice, 7, e108. https://doi.org/10.1016/j.orcp.2013.12.694

Gill, D. L., Fasczewski, K. S., Reifsteck, E. J., Rothberger, S. M., & Davis, P. G. (2018). Evaluation of an exercise program for post-bariatric surgery patients: views of participants. Obesity Science & Practice, 4(3), 259–267. https://doi.org/10.1002/osp4.165

Hong, S. H., Yang, H. I., Kim, D.-I., Gonzales, T. I., Brage, S., & Jeon, J. Y. (2019). Validation of Submaximal Step Tests and the 6-Min Walk Test for Predicting Maximal Oxygen Consumption in Young and Healthy Participants. International Journal of Environmental Research and Public Health, 16(23). https://doi.org/10.3390/ijerph16234858

Lukaski, H. C. (2004). Vitamin and mineral status: Effects on physical performance. Nutrition, 20(7–8), 632–644. https://doi.org/10.1016/j.nut.2004.04.001

Park, C. W., & Torquati, A. (2011). Physiology of weight loss surgery. The Surgical Clinics of North America, 91(6), 1149–vii. https://doi.org/10.1016/j.suc.2011.08.009

Petering, R., & Webb, C. W. (2009). Exercise, fluid, and nutrition recommendations for the postgastric bypass exerciser. Current Sports Medicine Reports, 8(2), 92–97. https://doi.org/10.1249/jsr.0b013e31819e2cd6

Sherf Dagan, S., Goldenshluger, A., Globus, I., Schweiger, C., Kessler, Y., Kowen Sandbank, G., Ben-Porat, T., & Sinai, T. (2017). Nutritional recommendations for adult bariatric surgery patients: Clinical practice. Advances in Nutrition: An International Review Journal, 8(2), 382–394. https://doi.org/10.3945/an.116.014258

Stegen, S., Derave, W., Calders, P., Van Laethem, C., & Pattyn, P. (2009). Physical fitness in morbidly obese patients: Effect of gastric bypass surgery and exercise training. Obesity Surgery, 21(1), 61–70. https://doi.org/10.1007/s11695-009-0045-y


Tags: Weight Loss

The Author

Nicole Golden

Nicole Golden

Nicole Golden is a NASM Master Trainer, CES, BCS, FNS and AFAA-Primary Group Exercise Instructor and graduate student at Concordia University Chicago. She has been a health/fitness professional since 2014 when she left the field of education to pursue a full-time career in fitness. Nicole is the owner of FWF Wellness where she specializes in corrective exercise and weight loss coaching. She has a great deal of experience working with Bariatric patients and cancer patients/cancer survivors. She also has a special interest in coaching clients within the drug and alcohol recovery community. Nicole enjoys spending time with her husband and five children when she is not training clients or teaching fitness classes.