Grubic, Tyler Joseph (2018-11). Effects of Consuming a Food Bar Containing Whey Protein and Isomalto-Oliosaccharides on Glucose Homeostasis, Exercise Performance and Recovery. Doctoral Dissertation.
Thesis
The pharmacokinetic study examined the glucose and insulinemic responses of ingesting a novel protein bar using plant fiber (isomalto-oligosaccharides, IMO). The purpose of the study was to determine the glycemic index (GI) and glycemic load (GL) during a 2 hour oral glucose tolerance test (OGTT). The study was performed in two parts. First, participants ingested a 25 g food bar (FB) or matched 25 g dextrose (PLA). Later, ten fasted individuals participated the same experiment while ingesting 2 FB's or 50 g of PLA. OGTT results revealed the FB had a GI of 34 [CI 23, 46] and a GL of 8.5 [CI 5.6, 11.6]. Interestingly, the FB elicited a lower glycemic response with a similar insulin response compared to the PLA. In response, the Exercise Study examined whether consuming this FB or 25 g PLA prior to, during, and following intense exercise would affect exercise performance and/or recovery in twelve resistance-trained males. Participants performed 11 resistance-exercises followed by sprint conditioning drills for time. Participants donated blood samples, performed isokinetic strength tests, and rated perceptions of muscle soreness and hypoglycemia prior to, following exercise and after 48 hours of recovery. Data were analyzed by general linear model repeated measures and are reported as mean change from baseline with 95% confidence intervals. Results revealed blood glucose was significantly higher 30-min post-ingestion with PLA (PLA 3.1 [2.0, 4.3], FB 0.8 [0.2, 1.5] mmol/L, p=0.001) while post-exercise ratio of insulin to glucose was greater with FB (PLA 0.04 [0.00, 0.08], FB 0.11 [0.07, 0.15], p=0.013, ?^2=0.25). Total lifting volume was maintained to a greater degree from Set 1 to Set 3 with FB than PLA (PLA -198.26 [-320.1, -76.4], FB -81.7 [-203.6, 40.1] kg, p=0.175, ?^2=0.08). Perceived muscle soreness was lower with FB (PLA 1.88 [0.60, 3.17]; FB 0.29[-0.99, 1.57] cm, p=0.083, ?^2=0.13). No significant differences were observed between treatments in sprint performance, isokinetic strength, markers of catabolism, stress and sex hormones, or inflammatory markers. Results indicate that ingestion of this FB can positively affect glucose homeostasis, sustain exercise performance, and lessen perceptions of muscle soreness after intense training.
