Software for the rapid and automatic calculation of physiological parameters corresponding to the maximum consumption of lipids during exercise

Introduction Numerous studies have described the relationship between exercise intensity and fat oxidation, but few have assessed this relation at different exercise intensities. Most exercise programs for obese patients and resistance training for athletes, have been evaluated for their respiratory and cardiovascular benefits and increased oxidative capacity in skeletal muscle. The study of fat metabolism, induced by training during exercise, has received less attention, although its importance has been recognized both in performance sports and for its impact on health [1-4]. It is therefore imperative to precisely define rigorous standardization procedures (feeding, pre-test activities, test protocol, etc.) that allow a reliable determination of the maximum consumption of lipids (FatMax). In addition, for routine use such procedures should be integrated with an appropriate software to automatically determine parameters of physiological interest, related to the FatMax, in a robust and operator-independent manner. Methods Our group has developed an automatic procedure for determining FatMax, both in terms of load applied and in terms of parameters such as heart rate and RER. The program uses a robust curve fitting procedure for reliable results. The initial application for this procedure is the determination of exercise prescription for overweight subjects, with the aim of maximizing fat loss for a given exercise duration. In the study currently underway, we have recruited 16 subjects (14 female, age 40-54 years, BMI 23-34), who have undergone an initial incremental test to determine their individual FatMax, followed by twice weekly sessions lasting 1 hour, during which the subjects exercise on bike, steps and treadmill for 20 minutes each. During the session a heart rate monitor is used to hit the target heart rate prescribed, and a respirometer to check that the target RER is achieved. At the end of the study period a final incremental test will be performed to ascertain whether relevant physiological parameters have been altered by the training. Results The study is currently underway. The latest results will be presented, emphasizing the design and use of the software that we have developed, and aim to make freely available. References 1. Van Aggel-Leijessen DP, et al. Metabolism 2002; 51:1003-10 2. Turcotte LP, et al. Am J Physiol 1992; 262:E791-E799 3. Romijn JA, et al. Am J Physiol 1993;265:E380–91 4. Jeukendrup AE. CurrOpinClinNutr 1999; 62:999-1005