Effects of Wild Blueberries on Fat Oxidation Rates in Aerobically Trained Males.

Wild blueberries (WBs) have been documented to decrease oxidative stress in active and sedentary populations as well as influence lipolytic enzymes and increase the rate of fat oxidation (FAT-ox) during rest. To examine the effect of WBs on the rate of FAT-ox and lipid peroxidation during submaximal exercise, 11 healthy, aerobically trained males (26 ± 7.5 years, 74.9 ± 7.54 kg, 10.5 ± 3.2% BF) completed a 2-week washout avoiding foods high in anthocyanins, then completed a control exercise protocol cycling at 65% of VO2peak for 40 min. Participants then consumed 375 g/d of anthocyanins for two weeks before repeating the exercise protocol. WBs increased FAT-ox when cycling at 65% of VO2peak by 19.7% at 20, 43.2% at 30, and 31.1% at 40 min, and carbohydrate oxidation (CHO-ox) decreased by 10.1% at 20, 19.2% at 30, and 14.8% at 40 min of cycling at 65% of VO2peak. Lactate was lower with WBs at 20 (WB: 2.6 ± 1.0, C: 3.0 ± 1.1), 30 (WB: 2.2 ± 0.9, C: 2.9 ± 1.0), and 40 min (WB: 1.9 ± 0.8, C: 2.5 ± 0.9). Results indicate that WBs may increase the rate of FAT-ox during moderate-intensity activity in healthy, active males.

Cycling with Short Crank Lengths Improved Economy in Novices.

Novice endurance athletes utilize slower movements and smaller ranges of motion compared to trained endurance athletes. Novice cyclists have been shown to follow this paradigm via the use of slower cadences but may further benefit by utilizing shorter crank lengths to affect speed of movement and range of motion. The purpose of the study was to determine the impact of shorter than traditional crank lengths on the physiological response and performance of novice cyclists exercising at 60% of VO2peak. A total of 14 male novice cyclists (25.9 ± 6.9 yrs.) participated in the study. Participants completed an incremental cycle test to determine VO2peak. Experimental trials consisted of 30 min cycling bouts at 60% of VO2peak; one session using a traditional crank length (175 mm), the other used a short crank length (145 mm). Experimental trials were randomized. Repeated Measures ANOVAs were used to compare power output, cycling economy, RER, VE, HR, RPE, pedal speed and cadence between crank length conditions. Power output (p = 0.002) and cycling economy (p = 0.002) were significantly higher at all time points during the short crank length condition. Pedal speed (p = 0.001) was significantly lower at all time points during the short crank length condition. Novice cyclists were able to ride with improved economy and higher power output while using short crank lengths. These improvements may be related to the slower pedal speeds, slower muscle contraction velocities and more extended hip and knee joints that a short crank length affords.