Time to move beyond a brainless exercise physiology: the evidence for complex regulation of human exercise performance

2011 ◽  
Vol 36 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Timothy David Noakes
Keyword(s):  
Exercise Performance ◽  
Perceived Exertion ◽  
Exercise Physiology ◽  
Nobel Laureate ◽  
Exercise Duration ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
Hill Model ◽  
The Hill ◽  
The Brain

In 1923, Nobel Laureate A.V. Hill proposed that maximal exercise performance is limited by the development of anaerobiosis in the exercising skeletal muscles. Variants of this theory have dominated teaching in the exercise sciences ever since, but 90 years later there is little biological evidence to support Hill’s belief, and much that disproves it. The cardinal weakness of the Hill model is that it allows no role for the brain in the regulation of exercise performance. As a result, it is unable to explain at least 6 common phenomena, including (i) differential pacing strategies for different exercise durations; (ii) the end spurt; (iii) the presence of fatigue even though homeostasis is maintained; (iv) fewer than 100% of the muscle fibers have been recruited in the exercising limbs; (v) the evidence that a range of interventions that act exclusively on the brain can modify exercise performance; and (vi) the finding that the rating of perceived exertion is a function of the relative exercise duration rather than the exercise intensity. Here I argue that the central governor model (CGM) is better able to explain these phenomena. In the CGM, exercise is seen as a behaviour that is regulated by complex systems in the central nervous system specifically to ensure that exercise terminates before there is a catastrophic biological failure. The complexity of this regulation cannot be appreciated if the body is studied as a collection of disconnected components, as is the usual approach in the modern exercise sciences.

Breaking Away: Effects of Nonuniform Pacing on Power Output and Growth of Rating of Perceived Exertion

2013 ◽  
Vol 8 (4) ◽  
pp. 352-357 ◽  
Author(s):  
Jacob Cohen ◽  
Bridgette Reiner ◽  
Carl Foster ◽  
Jos J. de Koning ◽  
Glenn Wright ◽  
...  
Keyword(s):  
Power Output ◽  
Cycle Time ◽  
Growth Pattern ◽  
Perceived Exertion ◽  
Time Trial ◽  
Normal Growth ◽  
Reciprocal Relationship ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
The Brain

The rating of perceived exertion (RPE) normally grows as a scalar function of relative competitive distance, suggesting that it may translate between the brain and body relative to managing fatigue during time-trial exercise. In nonstandard pacing situations, a reciprocal relationship between RPE and power output (PO) would be predicted.Purpose:To determine whether PO would decrease when RPE was forced above the normal growth curve during a cycle time trial.Methods:Well-trained cyclists performed randomly ordered 10-km cycle time trials. In CONTROL they rode at their own best pace throughout. In BURST, they made a 1-km “burst” at the 4-km mark and then finished as rapidly as possible.Results:CONTROL was significantly (P < .05) faster than BURST (16:36 vs 17:00 min). During CONTROL, responses between 4 and 5 km were PO, 240 W; RPE, 5–6; and blood lactate [HLa], 8–9 mmol/L. During BURST PO increased to 282 W, then fell to 220 W after the burst and remained below CONTROL until the end spurt (9 km). RPE increased to 9 during the burst but returned to the normal RPE growth pattern by 6 km; [HLa] increased to ~13 mmol/L after the burst and remained elevated throughout the remainder of the trial.Conclusions:The reciprocal behavior of RPE and PO after BURST supports the hypothesis that RPE translates between the brain and the body during heavy exercise. However, the continuing reduction of PO after the burst, even after RPE returned to its normal growth pattern, suggests that PO is regulated in a more complex manner than reflected solely by RPE.

Increases in Circulating Cell-Free DNA During Aerobic Running Depend on Intensity and Duration

2017 ◽  
Vol 12 (4) ◽  
pp. 455-462 ◽  
Author(s):  
Nils Haller ◽  
Suzan Tug ◽  
Sarah Breitbach ◽  
Arne Jörgensen ◽  
Perikles Simon
Keyword(s):  
Perceived Exertion ◽  
Exercise Physiology ◽  
Intraclass Correlation ◽  
Exercise Duration ◽  
Rating Of Perceived Exertion ◽  
Full Potential ◽  
Vigorous Exercise ◽  
Cell Free Dna ◽  
Free Dna ◽  
Circulating Cell Free Dna

Purpose:Increases in concentrations of circulating cell-free DNA (cfDNA) have recently been demonstrated to occur in a variety of exhausting and vigorous exercise settings. Here, the authors assessed the association of cfDNA with exercise duration and intensity in a controlled test–retest setting of a regenerative up-to-moderate-level aerobic run.Methods:In a pretest, the lactate threshold (LT) was determined in 13 participants (range 10.8–13.4 km/h) by using a step-wise incremental running test. The speed of the 2 endurance runs was set to 9.6 km/h for 40 min; for the participants with an LT below the median (12.8 km/h; G1), this was a moderate aerobic run, and for those with an LT above the median, this was a regenerative run (G2). Capillary cfDNA, lactate, and rating of perceived exertion (RPE) were assessed before, every 10 min during, and after the runs.Results:During the last 30 min of the 2 runs, lactate did not increase, whereas cfDNA increased steadily (3.46-fold for G1 and 2.05-fold for G2). Intraclass correlation for cfDNA was high (r = .81, P < .0001) for all runners but higher for male participants (r = .92, P < .0001). The correlations of cfDNA and lactate with RPEs were r = .58 (P < .0001) and r = .32 (P < .05), respectively.Conclusions:Both duration and level of intensity were significantly associated with accumulation of cfDNA. The correlation with RPE and the high test–retest reliability suggest that cfDNA might be applicable as a marker to monitor individual training load for aerobic and intermittent exercises. Future randomized, controlled, longitudinal training studies will have to reveal the full potential of cfDNA as an exercise-physiology marker.

scholarly journals External and Internal Loads in Sports Science: Time to Rethink?

2021 ◽  
Author(s):  
Bernardo Ide ◽  
Amanda Silvatti ◽  
Craig Staunton ◽  
Moacir Marocolo ◽  
Dustin Oranchuk ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Biological Tissues ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
Measuring System ◽  
Internal Load ◽  
Sports Science ◽  
System Of Units ◽  
Time Distance ◽  
Displacement Speed

The International System of Units (SI) was adopted in 1960 as a universal measuring system to be used for all areas of science. Sports Science papers have shown lots of inaccurate and inappropriate terms for quantification of athletes&rsquo; performance and the psychobiological responses to exercise (e.g., internal load). In biomechanics, external and internal loads are forces acting externally and internally, inducing stress and strain in the biological tissues. Therefore, the current review present simple proposals to correct the inappropriate terms: 1) do not use the term external load when referring to the assessment of exercise time, distance, displacement, speed, velocity, acceleration, torque, work, power, impulse, etc.; 2) do not use the term internal load when referring to the assessment of psychobiological stress markers (i.e., session rating of perceived exertion, heart rate, blood lactate, oxygen consumption, etc.); 3) do not use the term impulse when expressing other calculus than integrating force with respect to time, and neither strain, when expressing other phenomena than the body deformation. Instead, the term exercise intensity is universal and can be used to describe all forms of exercise. Finally, duration should precisely be described according to physical quantities (e.g., time, distance, displacement, speed, velocity, acceleration, force, torque, work, power, impulse, etc.) and the units accomplish by use of the SI. These simple quantifications can be performed for the exercises, sessions, microcycles, mesocycles and macrocycles of the athletes. Such standardization will provide a consistent and clear communication among sports scientists and all areas of science.

Carbohydrate mouth rinsing improves resistance training session performance

2018 ◽  
Vol 13 (5) ◽  
pp. 804-809 ◽  
Author(s):  
Luciana S Decimoni ◽  
Victor M Curty ◽  
Livia Almeida ◽  
Alexander J Koch ◽  
Jeffrey M Willardson ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Exercise Performance ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Bench Press ◽  
Statistical Significance ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Double Blind ◽  
Mouth Rinsing

We investigated the effect of carbohydrate mouth rinsing on resistance exercise performance. Fifteen recreationally trained women (age 26 ± 4 y; height 1.61.9 ± 5.1 m; weight 59.5 ± 8.2 kg) completed two resistance exercise bouts consisting of three sets of five exercises (half-squat, leg press, bench press, military press, and seated row) to volitional fatigue with a 10 repetition-maximum load. Immediately prior to and during the middle of each exercise bout, subjects mouth rinsed for 10 s with 100 mL of either a 6% maltodextrin solution (CHO) or an artificially flavored solution (PLA) in a randomized, double-blind, counterbalanced fashion. Heart rate and perceived exertion were compared between conditions using a 2 (conditions) × 15 (time points) repeated measures ANOVA. Significant main effects were further analyzed using pairwise comparisons with Bonferroni post hoc tests. Total volume (exercises * sets * repetitions * load) between sessions was compared with a Student’s t-test. Statistical significance was set at p ≤ 0.05 level of confidence. The CHO resulted in more repetitions performed during half-squat, bench press, military press, and seated row, for a significantly greater (∼12%) total volume load lifted versus PLA ( p = 0.039, ES: 0.49). Rating of perceived exertion was also significantly lower in the CHO versus PLA ( p = 0.020, ES: 0.28). These data indicate that CHO mouth rinsing can enhance high-volume resistance exercise performance and lower ratings of perceived exertion.

Time Spent Near V˙O2max During Different Cycling Self-Paced Interval Training Protocols

2020 ◽  
pp. 1-7
Author(s):  
Cristiano Dall’ Agnol ◽  
Tiago Turnes ◽  
Ricardo Dantas De Lucas
Keyword(s):  
Power Output ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Interval Training ◽  
Exercise Duration ◽  
Rating Of Perceived Exertion ◽  
Recovery Ratio ◽  
Active Recovery ◽  
Mean Power ◽  
Work Recovery

Purpose: Cyclists may increase exercise intensity by prolonging exercise duration and/or shortening the recovery period during self-paced interval training, which could impact the time spent near . Thus, the main objective of this study was to compare the time spent near during 4 different self-paced interval training sessions. Methods: After an incremental test, 11 cyclists (mean [SD]: age = 34.4 [6.2] y; ) performed in a randomized order 4 self-paced interval training sessions characterized by a work–recovery ratio of 4:1 or 2:1. Sessions comprised 4 repetitions of 4 minutes of cycling with 1 minute (4/1) or 2 minutes (4/2) of active recovery or 8 minutes of cycling with 2 minutes (8/2) or 4 minutes (8/4) of active recovery. Time spent at 90% to 94% (), ≥95% (), and 90% to 100% () was analyzed in absolute terms and relative to the total work duration. Power output, heart rate, blood lactate, and rating of perceived exertion were compared. Results: The 8/4 session provided higher absolute and than 8/2 (P = .015 and .029) and 4/1 (P = .002 and .047). The 4/2 protocol elicited higher relative (47.7% [26.9%]) and (23.5% [22.7%]) than 4/1 (P = .015 and .028) and 8/2 (P < .01). Session 4/2 (275 [23] W) elicited greater mean power output (P < .01) than 4/1 (261 [27] W), 8/4 (250 [25] W), and 8/2 (234 [23] W). Conclusions: Self-paced interval training composed of 4-minute and 8-minute work periods efficiently elicit , but protocols with a work–recovery ratio of 2:1 (ie, 4/2 and 8/4) could be prioritized to maximize .

Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

2020 ◽  
Vol 15 (3) ◽  
pp. 298-308 ◽  
Author(s):  
Pedro L. Valenzuela ◽  
Javier S. Morales ◽  
Adrián Castillo-García ◽  
Alejandro Lucia
Keyword(s):  
Randomized Controlled Trials ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Meta Analysis ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Controlled Trials ◽  
Glucose Levels ◽  
Randomized Controlled ◽  
Control Intervention

Purpose: To determine the acute effects of ketone supplementation on exercise performance (primary outcome) and physiological and perceptual responses to exercise (secondary outcomes). Methods: A systematic search was conducted in PubMed, Web of Science, and SPORTDiscus (since inception to July 21, 2019) to find randomized controlled trials assessing the effects of acute ketone supplementation compared with a drink containing no ketones (ie, control intervention). The standardized mean difference (Hedges g) between interventions and 95% confidence interval (CI) were computed using a random-effects model. Results: Thirteen studies met all inclusion criteria. No significant differences were observed between interventions for overall exercise performance (Hedges g = −0.05; 95% CI, −0.30 to 0.20; P = .68). Subanalyses revealed no differences between interventions when analyzing endurance time-trial performance (g = −0.04; 95% CI, −0.35 to 0.28; P = .82) or when assessing the separate effects of supplements containing ketone esters (g = −0.07; 95% CI, −0.38 to 0.24; P = .66) or salts (g = −0.02; 95% CI, −0.45 to 0.41; P = .93). All studies reported increases in plasma ketone concentration after acute ketone supplementation, but no consistent effects were reported on the metabolic (plasma lactate and glucose levels), respiratory (respiratory exchange ratio, oxygen uptake, and ventilatory rate), cardiovascular (heart rate), or perceptual responses to exercise (rating of perceived exertion). Conclusions: The present findings suggest that ketone supplementation exerts no clear influence on exercise performance (from sprints to events lasting up to ∼50 min) or metabolic, respiratory, cardiovascular, or perceptual responses to exercise. More research is needed to elucidate if this strategy could provide ergogenic effects on other exercise types (eg, ultraendurance exercise).

scholarly journals Ecological Validity of the Session Rating of Perceived Exertion for Quantifying Internal Training Load in Fencing

2017 ◽  
Vol 12 (1) ◽  
pp. 124-128 ◽  
Author(s):  
Anthony N. Turner ◽  
Conor Buttigieg ◽  
Geoff Marshall ◽  
Angelo Noto ◽  
James Phillips ◽  
...  
Keyword(s):  
Heart Rate ◽  
Correlation Analysis ◽  
Individual Variation ◽  
Coefficient Of Variation ◽  
Perceived Exertion ◽  
Ecological Validity ◽  
Exercise Duration ◽  
Training Load ◽  
Rating Of Perceived Exertion ◽  
Competitive Season

Session rating of perceived exertion (sRPE) is known to significantly relate to heart-rate (HR) -based methods of quantifying internal training load (TL) in a variety of sports. However, to date this has not been investigated in fencing and was therefore the aim of this study. TL was calculated by multiplying the sRPE with exercise duration and through HR-based methods calculated using Banister and Edwards TRIMP. Seven male elite foil fencers (mean ± SD age 22.3 ± 1.6 y, height 181.3 ± 6.5 cm, body mass 77.7 ± 7.6 kg) were monitored over the period of 1 competitive season. The sRPE and HR of 67 training sessions and 3 competitions (87 poule bouts and 12 knockout rounds) were recorded and analyzed. Correlation analysis was used to determine any relationships between sRPE- and HR-based methods, accounting for individual variation, mode of training (footwork drills vs sparring sessions), and stage of competition (poules vs knockouts). Across 2 footwork sessions, sRPE and Banister and Edwards TRIMP were found to be reliable, with coefficient of variation values of 6.0%, 5.2%, and 4.5%, respectively. Significant correlations with sRPE for individual fencers (r = .84–.98) and across mode of exercise (r = .73–.85) and competition stages (r = .82–.92) were found with HR-based measures. sRPE is a simple and valuable tool coaches can use to quantify TL in fencing.

Effects Of Caffeine On Resistance Exercise Performance, Mood, Heart Rate, And Rating Of Perceived Exertion

2010 ◽  
Vol 42 ◽  
pp. 443-444
Author(s):  
Edward Jo ◽  
Michael Martinez ◽  
Brown E. Lee ◽  
Jared W. Coburn ◽  
Biagini Matthew ◽  
...  
Keyword(s):  
Heart Rate ◽  
Resistance Exercise ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion

scholarly journals Effects of almond, dried grape and dried cranberry consumption on endurance exercise performance, recovery and psychomotor speed: protocol of a randomised controlled trial

2019 ◽  
Vol 5 (1) ◽  
pp. e000560 ◽  
Author(s):  
Noah Marc Adrian d'Unienville ◽  
Alison Hill ◽  
Alison Coates ◽  
Catherine Yandell ◽  
Max Nelson ◽  
...  
Keyword(s):  
Heart Rate ◽  
Endurance Training ◽  
Endurance Exercise ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Well Being ◽  
Rating Of Perceived Exertion ◽  
Snack Food ◽  
Psychomotor Speed ◽  
Performance Recovery

BackgroundFoods rich in nutrients, such as nitrate, nitrite, L-arginine and polyphenols, can promote the synthesis of nitric oxide (NO), which may induce ergogenic effects on endurance exercise performance. Thus, consuming foods rich in these components, such as almonds, dried grapes and dried cranberries (AGC), may improve athletic performance. Additionally, the antioxidant properties of these foods may reduce oxidative damage induced by intense exercise, thus improving recovery and reducing fatigue from strenuous physical training. Improvements in NO synthesis may also promote cerebral blood flow, which may improve cognitive function.Methods and analysisNinety-six trained male cyclists or triathletes will be randomised to consume ~2550 kJ of either a mixture of AGC or a comparator snack food (oat bar) for 4 weeks during an overreaching endurance training protocol comprised of a 2-week heavy training phase, followed by a 2-week taper. The primary outcome is endurance exercise performance (5 min time-trial performance) and secondary outcomes include markers of NO synthesis (plasma and urinary nitrites and nitrates), muscle damage (serum creatine kinase and lactate dehydrogenase), oxidative stress (F2-isoprostanes), endurance exercise function (exercise efficiency, submaximal oxygen consumption and substrate utilisation), markers of internal training load (subjective well-being, rating of perceived exertion, maximal rate of heart rate increase and peak heart rate) and psychomotor speed (choice reaction time).ConclusionThis study will evaluate whether consuming AGC improves endurance exercise performance, recovery and psychomotor speed across an endurance training programme, and evaluate the mechanisms responsible for any improvement.Trial registration numberACTRN12618000360213.

Effects of Preferred and Nonpreferred Warm-Up Music on Exercise Performance

2020 ◽  
Vol 127 (5) ◽  
pp. 912-924 ◽  
Author(s):  
Morgan C. Karow ◽  
Rebecca R. Rogers ◽  
Joseph A. Pederson ◽  
Tyler D. Williams ◽  
Mallory R. Marshall ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Performance ◽  
Power Output ◽  
Perceived Exertion ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Relative Power ◽  
Warm Up ◽  
Trial Time ◽  
Condition Versus

This study investigated the effects of preferred and non-preferred warm-up music listening conditions on subsequent exercise performance. A total of 12 physically active male and female participants engaged in a crossover, counterbalanced research design in which they completed exercise trials after 3 different warm-up experiences of (a) no music (NM), (b) preferred music (PREF), and (c) nonpreferred music (NON-PREF). Participants began warming up by rowing at 50% of of age-predicted heart rate maximum (HRmax) for 5 minutes while exposed to the three music conditions. Immediately following the warm-up and cessation of any music, participants completed a 2000-m rowing time trial as fast as possible. Relative power output, trial time, heart rate, rating of perceived exertion, and motivation were analyzed. Results indicated that, compared with NM, relative power output was significantly higher ( p  =   .018), trial time was significantly lower ( p  =   .044), and heart rate was significantly higher ( p  =   .032) during the PREF but not the NON-PREF condition. Rating of perceived exertion was not altered, regardless of music condition ( p > .05). Motivation to exercise was higher during the PREF condition versus the NM ( p  =   .001) and NON-PREF ( p <  .001) conditions. Listening to preferred warm-up music improved subsequent exercise performance compared with no music, while nonpreferred music did not impart ergogenic benefit.

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