The differential effect of metabolic alkalosis on maximum force and rate of force development during repeated, high-intensity cycling

The purpose of this investigation was to assess the influence of sodium bicarbonate supplementation on maximal force production, rate of force development (RFD), and muscle recruitment during repeated bouts of high-intensity cycling. Ten male and female ( n = 10) subjects completed two fixed-cadence, high-intensity cycling trials. Each trial consisted of a series of 30-s efforts at 120% peak power output (maximum graded test) that were interspersed with 30-s recovery periods until task failure. Prior to each trial, subjects consumed 0.3 g/kg sodium bicarbonate (ALK) or placebo (PLA). Maximal voluntary contractions were performed immediately after each 30-s effort. Maximal force (Fmax) was calculated as the greatest force recorded over a 25-ms period throughout the entire contraction duration while maximal RFD (RFDmax) was calculated as the greatest 10-ms average slope throughout that same contraction. Fmax declined similarly in both the ALK and PLA conditions, with baseline values (ALK: 1,226 ± 393 N; PLA: 1,222 ± 369 N) declining nearly 295 ± 54 N [95% confidence interval (CI) = 84–508 N; P < 0.006]. RFDmax also declined in both trials; however, a differential effect persisted between the ALK and PLA conditions. A main effect of condition was observed across the performance time period, with RFDmax on average higher during ALK (ALK: 8,729 ± 1,169 N/s; PLA: 7,691 ± 1,526 N/s; mean difference between conditions 1,038 ± 451 N/s, 95% CI = 17–2,059 N/s; P < 0.048). These results demonstrate a differential effect of alkalosis on maximum force vs. maximum rate of force development during a whole body fatiguing task.

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The effect of rate of force development on maximal force production: acute and training-related aspects

European Journal of Applied Physiology ◽

10.1007/s00421-006-0380-9 ◽

2007 ◽

Vol 99 (6) ◽

pp. 605-613 ◽

Cited By ~ 53

Author(s):

Andreas Holtermann ◽

Karin Roeleveld ◽

Beatrix Vereijken ◽

Gertjan Ettema

Keyword(s):

Force Production ◽

Rate Of Force Development ◽

Force Development ◽

Maximal Force ◽

And Training

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Lack of increased rate of force development after strength training is explained by specific neural, not muscular, motor unit adaptations

Journal of Applied Physiology ◽

10.1152/japplphysiol.00218.2021 ◽

2021 ◽

Author(s):

Alessandro Del Vecchio ◽

Andrea Casolo ◽

Jakob Lund Dideriksen ◽

Per Aagaard ◽

Francesco Felici ◽

...

Keyword(s):

Strength Training ◽

Motor Unit ◽

Discharge Rate ◽

Force Production ◽

Population Data ◽

Motor Units ◽

Rate Of Force Development ◽

Force Development ◽

Maximal Force ◽

Contraction Speed

While maximal force increases following short-term isometric strength training, the rate of force development (RFD) may remain relatively unaffected. The underlying neural and muscular mechanisms during rapid contractions after strength training are largely unknown. Since strength training increases the neural drive to muscles, it may be hypothesized that there are distinct neural or muscular adaptations determining the change in RFD independently of an increase in maximal force. Therefore, we examined motor unit population data acquired from surface electromyography during the rapid generation of force before and after four weeks of strength training. We observed that strength training did not change the RFD because it did not influence the number of motor units recruited per second or their initial discharge rate during rapid contractions. While strength training did not change motoneuron behaviour in the force increase phase of rapid contractions, it increased the discharge rate of motoneurons (by ~4 spikes/s) when reaching the plateau phase (~150 ms) of the rapid contractions, determining an increase in maximal force production. Computer simulations with a motor unit model that included neural and muscular properties, closely matched the experimental observations and demonstrated that the lack of change in RFD following training is primarily mediated by an unchanged maximal recruitment speed of motoneurons. These results demonstrate that maximal force and contraction speed are determined by different adaptations in motoneuron behaviour following strength training and indicate that increases in the recruitment speed of motoneurons are required to evoke training-induced increases in RFD.

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Effects of 4 Weeks Whole Body Vibration on Electromechanical Delay, Rate of Force Development, and Presynaptic Inhibition

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000402593.82240.7c ◽

2011 ◽

Vol 43 (Suppl 1) ◽

pp. 928 ◽

Cited By ~ 1

Author(s):

Junggi Hong ◽

Kristof Kipp ◽

Samuel T. Johnson ◽

Mark A. Hoffman

Keyword(s):

Presynaptic Inhibition ◽

Whole Body Vibration ◽

Rate Of Force Development ◽

Whole Body ◽

Electromechanical Delay ◽

Body Vibration ◽

Force Development

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The specificity of explosive force production capacity quantified with the isometric rate of force development during leg extension in several sports athletes

Taiikugaku kenkyu (Japan Journal of Physical Education Health and Sport Sciences) ◽

10.5432/jjpehss.21077 ◽

2022 ◽

Author(s):

Kodayu ZUSHI ◽

Yasushi KARIYAMA ◽

Takuya YOSHIDA ◽

Amane ZUSHI ◽

Keigo OHYAMA-BYUN ◽

...

Keyword(s):

Production Capacity ◽

Force Production ◽

Rate Of Force Development ◽

Leg Extension ◽

Force Development ◽

Explosive Force

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Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2015-0371 ◽

2016 ◽

Vol 41 (4) ◽

pp. 354-361 ◽

Cited By ~ 4

Author(s):

Matthew F. Higgins ◽

Susie Wilson ◽

Cameron Hill ◽

Mike J. Price ◽

Mike Duncan ◽

...

Keyword(s):

Sodium Chloride ◽

Sodium Bicarbonate ◽

Body Mass ◽

High Intensity ◽

Peak Oxygen Uptake ◽

Ion Concentration ◽

Peak Power Output ◽

Double Blind ◽

Blood Ph ◽

Experimental Trials

This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg−1·min−1) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg−1 body mass sodium bicarbonate (BIC), (ii) 5 mg·kg−1 body mass caffeine plus 0.1 g·kg−1 body mass sodium chloride (CAF), (iii) 0.3 g·kg−1 body mass sodium bicarbonate plus 5 mg·kg−1 body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg−1 body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3−]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350–415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333–402 s; P = 0.028; r = 0.6) compared with BIC (313: 284–448 s) although not compared with PLA (358; 290–433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted.

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