Methods to Assess Energy Expenditure of Resistance Exercise: A Systematic Scoping Review

Background Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance. However, the significant contribution of anaerobic metabolism makes quantifying energy expenditure of resistance exercise challenging. Objective The aim of this scoping review was to investigate the methods used to assess resistance exercise energy expenditure. Methods A literature search of Medline, SPORTDiscus, CINAHL and Web of Science identified studies that included an assessment of resistance exercise energy expenditure. Quality appraisal of included studies was performed using the Rosendal Scale. Results A total of 19,867 studies were identified, with 166 included after screening. Methods to assess energy expenditure included indirect calorimetry ( n = 136), blood lactate analysis ( n = 25), wearable monitors ( n = 31) and metabolic equivalents ( n = 4). Post-exercise energy expenditure was measured in 76 studies. The reported energy expenditure values varied widely between studies. Conclusions Indirect calorimetry is widely used to estimate energy expenditure. However, given its limitations in quantifying glycolytic contribution, indirect calorimetry during and immediately following exercise combined with measures of blood lactate are likely required to better quantify total energy expenditure. Due to the cumbersome equipment and technical expertise required, though, along with the physical restrictions the equipment places on participants performing particular resistance exercises, indirect calorimetry is likely impractical for use outside of the laboratory setting, where metabolic equivalents may be a more appropriate method.