Bridging the Chasm
Over the past dozen years, perhaps the most interesting paradigm shift in exercise physiology is its open integration with the world of sport psychology. No longer two distinct and disconnected fields, more and more scientists on both sides of the great divide between the mind and the body are realizing that the chasm was actually “in the mind” rather than in reality.
Specifically, one of the hottest topics in exercise science is understanding the role of how physiological afferents (physical sensations like temperature, breathing rate, muscle strain, etc.) are integrated into an overall sensation of effort in the brain, and how this then becomes used by the body to determine how hard it can, or is willing, to work.
In my own field of thermophysiology, my studies have explored how much voluntary muscle recruitment we are capable of as we heat up, demonstrating that a rising core temperature decreases our voluntary muscle capacity. Others have shown that marathon performances worsen across all ability levels as it gets warmer, even though our actual physiological capacity to sprint in the latter stages of a run show that we’re nowhere near our physical capacity.
Stuck in a Groove
In the latest proposals for how the body fatigues and what factors go into it, another important mechanism or driving force is the “template” that the brain works from. While we may integrate physical sensations in real time, we all start with a pre-conceived plan for how we’ll tackle a race (let’s say a time trial to keep pack dynamics out of it).
This template includes many factors. The first and probably most important is simply prior experience. If you know and are convinced that your best ever 10 km TT is 15 min (40 km/h), subconsciously that’s the rough effort that you will default towards at the start. You won’t go at a 50 km/h average because you quickly receive physical sensations (e.g. high lactate levels, ventilation rate, and heart rate) that’s too hard to sustain. And you won’t put up with a 30 km/h average because you’ll just feel that is too slow.
From that initial 40 km/h template, you might “choose” to pace yourself a bit slower because you feel that it’s really hot out. Or you might be wearing the maglia rosa and have tons of motivation and confidence, and might therefore be much more willing to put up with the pain of a harder effort.
Wilson et al. 2012
So motivation and physically sensing the environment can adjust your default performance template. But what about the simple psychological trick of lying to yourself? Last week, Dr. Jim Taylor wrote about the powers of positive and negative self-talk. What if you were being told that you’re going better than you actually are? Or conversely, what if you were being told that you’re riding much slower than you actually are? Does external feedback of any kind even help?
This basic idea was the focus of a study from Wilson et al. in the European Journal of Applied Physiology in 2012 (Wilson et al. 2012). Seven “well-trained” cyclists (>8h cycling per week, experienced in time trials) performed 4×10 mile TTs on SRM stationary bikes. The four conditions involved:
1. Accurate feedback: participants were told a slate of information, including times, power output, speed, distance completed, etc. The paper did not state the frequency of such feedback. As the participants breathed through a mouthpiece for oxygen consumption, I would guess the feedback was at set times rather than ad lib or requested by the participants.
2. No feedback: as implied, no feedback of any kind.
3. False Positive feedback: at 1-mile intervals, participants were told their false split times, namely 5% faster than their actual performance.
4. False Negative feedback: at the same 1-mile intervals, split times of 5% slower than actual were provided.
Overall, 5% was chosen as a compromise, as a too large of a difference (e.g. 10%) would likely have made the participants realize that something fishy was up. The authors claimed that participants were deceived to the true purpose of the study, with them originally being told that the study was to test the reliability of a 10-mile TT protocol. However, I’m not sure how this could really be properly implemented, as one trial provided lots of different feedback, while another provided none at all and two others provided only one parameter.
The Truth, and Nothing but the Truth
The most important finding from the data? The presence or quality of the feedback didn’t seem to make any significant difference in performance results:
• Accurate feedback: 1547 +/- 73 s; 252 +/- 22 W
• No feedback: 1542 +/- 56 s; 243 +/- 24 W
• False Positive feedback: 1535 +/- 61 s; 244 +/- 23 W
• False Negative feedback: 1533 +/- 62 s; 243 +/- 27 W
Again, there were no statistical significance across the four trials in performance time, first and second half split times, or any physiological measures. However, I’m a bit confused by the data, in that the “slowest” condition (Accurate feedback) also had a 10 W higher average power output. Honestly, I’m a bit stumped at how to reconcile this, and the authors made no attempt to address this in the Discussion portion of the paper.
So scientifically, this was definitely not the best paper I’ve come across (the authors also made other extrapolations from their data that I’m not that confident in, but I’ll ignore that for the purpose of this article). But it is an interesting example of the integration of physiology and psychology in sport science.
If I was a coach or directeur sportif, what would I take from this study in terms of how to manage my riders? Objectively, it would appear to absolve them of any role, in that “boys will be boys” and an athlete will just do what they feel like doing regardless of external involvement.
I think it’s a bit more nuanced than that though. Every leader knows that different people respond to different buttons. Some in general may thrive on one style and be completely turned off by another. And that same person may also need different styles at different times. Given the limitations I found in this article, I wouldn’t stray from this principle yet.
Ride fast and have fun!
Wilson MG, Lane AM, Beedie CJ, Farooq A (2012) Influence of accurate and inaccurate ‘split-time’ feedback upon 10-mile time trial cycling performance. Eur J Appl Physiol 112:231-236
Stephen Cheung is a Canada Research Chair at Brock University, and has published over 70 scientific articles and book chapters dealing with the effects of thermal and hypoxic stress on human physiology and performance. Stephen’s Cutting-Edge Cycling, a book on the science of cycling, came out April 2012, and he can be reached for comments at firstname.lastname@example.org .