PURPOSE: The RBPE was designed to discover, via novel technologies & integrative science, the complexity of human performance, with the explicit goal of developing strategies that advance human athletic potential. This year’s project investigated the neurophysiological correlates (corticomotor excitability) of fatiguing exercise in world-class athletes, with contemporary methods of examining work and physiologic response. We aimed to identify if transcranial magnetic stimulation could identify a central reserve, how this changed with fatigue, and whether preceding interventional brain stimulation (tDCS) would alter this response. This paper focuses on cardio-respiratory responses and cycling performance during a 4k time-trial (4kTT) following repeated bouts of high-intensity exercise over a five day period.
METHODS: Four world-class athletes exhibiting four cycling phenotypes participated (BMX sprint cyclist, cyclo-cross bike racer, half-Ironman triathlete, and an extreme ultra-endurance mountain biker). Data collection included EEG, EMG, motion capture & velocity measures, maximal isometric force, cardio-respiratory function, cardiac impedance measurements, regional near-infrared measured oxygen saturation profiles, cycling performance during a 4k time-trial (4kTT), baseline hydration and segmental lean tissue, 24-hr sensor technologies for assessing blood glucose and stress-recovery heart rate variability measures, morning blood and urine samples, and blood samples before, during, and after key measurement points was also collected.
RESULTS: TMS had a positive effect on each athlete. Athletes with greater cycling endurance demands (triathlete and ultra- endurance cyclist) showed enhanced 4kTT performances with a corresponding increase in isometric max force development. Most interestingly these improvements took place despite each athlete exhibiting one or more of the following: blood markers of fatigue, extreme regional oxygen desaturation (≤ 20% oxygenate hemoglobin content during 90% of the 4kTT) with corresponding low blood oxygen content, and evidence of moderate/severe respiratory distress (respiration rates > 55 bpm). Additionally, with accumulated fatigue over the five days, cycling performance strategies changed in each cyclist’s cadence, gearing, and applied pedal force that either improved or did not improve their respective 4kTT results. CONCLUSIONS: These results indicate that TMS positively improved central brain silent periods. These results indicate 4kTT performance improvements were related to a cyclist’s performance phenotype & pedaling stroke force development strategies.