Yerba Maté (YM), the plant of (Illex Paraguariensis) is widely ingested for its potential health benefits including anti-atherogenic and weight loss properties( Reference Heck and de Mejia 1 ). We have previously shown an exercise intensity-dependent effect of acute YM ingestion on fatty acid oxidation (FAO), particularly at low and moderate exercise intensity domains, determined using an incremental exercise protocol( Reference Alkhatib 2 ). While, the augmented fat metabolism during those intensities implies improved exercise-metabolic weight-loss outcomes, the effects during prolonged exercise at this intensity range are unknown. This study aims to investigate the YM ingestion affects fat oxidation at prolonged moderate aerobic exercise intensities. We hypothesize that YM increase FAO during aerobic moderate intensity steady-state exercise.
Following the institutional approval, eleven healthy females (Mean ± SD, age = 30·8 ± 7·3 years, stature: 167·2 ± 3·9, body mass: 61·5 ± 2·8) followed an initial incremental cardiopulmonary assessment (25 W increased every 3 min until exhaustion) to determine their peak oxygen uptake (V˙O 2 peak) and the range of exercise intensities corresponding to the cross-over point (COP), defined as the intensity or power output at which energy expenditure from carbohydrate predominates over that from fat sources( Reference Brooks and Mercier 3 ). This intensity range is known to be effective for exercise-dependent weight-loss( Reference Brooks and Mercier 3 , Reference Venables and Jeukendrup 4 ). Participants were randomised to ingest either 2 g of YM or placebo capsules (PLC), in a double-blinded, placebo controlled, repeated measures design. Following the ingestion participants rested for 120 min rest before ergometry cycling constantly for 30 min at an intensity corresponding to their COP. FAO and energy expenditure from FAO (EEFAO) were calculated as previously shown in similar studies( Reference Alkhatib 2 ), and analysed using a Repeated measures ANOVA design.
The average COP intensity corresponded to (Mean ± SD, 37·3 ± 8·3 %, relative to V˙O 2 peak at a power output of (50·6 ± 23·4 W). At this power or intensity, it was found that YM significantly increased FAO across all time points compared with PLC (Table 1).
Table 1. Fatty Acid Oxidation rate (FAO) during 30 min of constant load exercise in the YM vs. PLC (p < 0·05, main ANOVA effect), all data presented as (Mean ± SD).
Acute ingestion of yerba mate can increase fat oxidation during moderate steady state intensity exercise, especially when the exercise is prescribed according to the individual's “fat-burning” intensities.
