EFFECT OF POTENTIATION AND STRETCHING ON MAXIMAL FORCE,RATE OF FORCE DEVELOPMENT, AND RANGE OF MOTION

Background: Exercise and vitamin C-enriched collagen supplementation increase collagen synthesis, potentially increasing matrix density, stiffness, and force transfer. Purpose: To determine whether vitamin C-enriched collagen (hydrolyzed collagen [HC] + C) supplementation improves rate of force development (RFD) alongside a strength training program. Methods: Using a double-blinded parallel design, over 3 weeks, healthy male athletes (n = 50, 18–25 years) were randomly assigned to the intervention (HC + C; 20 g HC + 50 mg vitamin C) or placebo (20 g maltodextrin). Supplements were ingested daily 60 min prior to training. Athletes completed the same targeted maximal muscle power training program. Maximal isometric squats, countermovement jumps, and squat jumps were performed on a force plate at the same time each testing day (baseline, Tests 1, 2, and 3) to measure RFD and maximal force development. Mixed-model analysis of variance compared performance variables across the study timeline, whereas t tests were used to compare the change between baseline and Test 3. Results: Over 3 weeks, maximal RFD in the HC + C group returned to baseline, whereas the placebo group remained depressed (p = .18). While both groups showed a decrease in RFD through Test 2, only the treatment group recovered RFD to baseline by Test 3 (p = .036). In the HC + C group, change in countermovement jumps eccentric deceleration impulse (p = .008) and eccentric deceleration RFD (p = .04) was improved. A strong trend was observed for lower limb stiffness assessed in the countermovement jumps (p = .08). No difference was observed in maximal force or squat jump parameters. Conclusion: The HC + C supplementation improved RFD in the squat and countermovement jump alongside training.

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

Journal of Applied Physiology ◽

10.1152/japplphysiol.00688.2013 ◽

2013 ◽

Vol 115 (11) ◽

pp. 1634-1640 ◽

Cited By ~ 10

Author(s):

Jason C. Siegler ◽

Paul W. M. Marshall ◽

Sean Raftry ◽

Cristy Brooks ◽

Ben Dowswell ◽

...

Keyword(s):

Sodium Bicarbonate ◽

High Intensity ◽

Differential Effect ◽

Force Production ◽

Rate Of Force Development ◽

Maximum Force ◽

Whole Body ◽

Peak Power Output ◽

Force Development ◽

Maximal Force

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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Rate of force development and maximal force: reliability and difference between non-climbers, skilled and international climbers

Sports Biomechanics ◽

10.1080/14763141.2019.1584236 ◽

2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Guillaume Levernier ◽

Guillaume Laffaye

Keyword(s):

Rate Of Force Development ◽

Force Development ◽

Maximal Force

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Four Weeks of Finger Grip Training Increases the Rate of Force Development and the Maximal Force in Elite and Top World-Ranking Climbers

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0000000000002230 ◽

2019 ◽

Vol 33 (9) ◽

pp. 2471-2480 ◽

Cited By ~ 4

Author(s):

Guillaume Levernier ◽

Guillaume Laffaye

Keyword(s):

Rate Of Force Development ◽

Force Development ◽

Maximal Force ◽

World Ranking

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Upper body rate of force development and maximal strength discriminates performance levels in sport climbing

PLoS ONE ◽

10.1371/journal.pone.0249353 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0249353

Author(s):

Nicolay Stien ◽

Vegard Albert Vereide ◽

Atle Hole Saeterbakken ◽

Espen Hermans ◽

Matthew Peter Shaw ◽

...

Keyword(s):

Rate Of Force Development ◽

The Other ◽

Upper Body ◽

Relative Time ◽

Force Development ◽

Absolute Time ◽

Time To Peak ◽

Maximal Force ◽

Sport Climbing ◽

Time Periods

The aim of this study was to assess and compare the maximal force and rate of force development (RFD) between intermediate, advanced and elite climbers using several different methods for calculating RFD. Fifty-seven male climbers (17 intermediate, 25 advanced, and 15 elite) performed isometric pull-ups on a climbing-specific hold while the RFD was calculated using several absolute (50, 100, 150, 200, and 250 ms from onset of force) and relative time periods (25, 50, 75, 95, and 100% of time to peak force). The maximal force was higher among elite climbers compared to advanced (ES = 1.78, p < 0.001) and intermediate climbers (ES = 1.77, p < 0.001), while no difference was observed between intermediate and advanced climbers (P = 0.898). The elite group also showed higher RFD than the other two groups at all relative time periods (ES = 1.02–1.58, p < 0.001–0.002), whereas the absolute time periods only revealed differences between the elite vs. the other groups at 50, 100 and 150 ms from the onset of force (ES = 0.72–0.84, p = 0.032–0.040). No differences in RFD were observed between the intermediate and advanced groups at any time period (p = 0.942–1.000). Maximal force and RFD, especially calculated using the longer periods of the force curve, may be used to distinguish elite climbers from advanced and intermediate climbers. The authors suggest using relative rather than absolute time periods when analyzing the RFD of climbers.

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The Effects of Prioritizing Lead or Boulder Climbing Among Intermediate Climbers

Frontiers in Sports and Active Living ◽

10.3389/fspor.2021.661167 ◽

2021 ◽

Vol 3 ◽

Author(s):

Nicolay Stien ◽

Tor Frithjof Frøysaker ◽

Espen Hermans ◽

Vegard Albert Vereide ◽

Vidar Andersen ◽

...

Keyword(s):

Body Mass ◽

Training Group ◽

Strength Test ◽

Rate Of Force Development ◽

Training Period ◽

Endurance Test ◽

Force Development ◽

Specific Strength ◽

Maximal Force

This study compared the effects of prioritizing lead climbing or boulder climbing on climbing-specific strength and endurance, as well as climbing performance. Fourteen active climbers were randomized to a boulder climbing training group (BCT: age = 27.2 ± 4.4 years, body mass = 65.8 ± 5.5 kg, height = 173.3 ± 3.8 cm) or a lead-climbing training group (LCT: age = 27.7 ± 6.1 years, body mass = 70.2 ± 4.4 kg, height = 177.7 ± 4.4 cm). The groups participated in a 5-week training period consisting of 15 sessions, performing either two weekly bouldering sessions and one maintenance-session of lead-climbing (BCT) or two weekly lead-climbing sessions and one maintenance-session of bouldering (LCT). Pre- and post-training, maximal force and rate of force development (RFD) were measured during isometric pull-ups performed on a jug hold and a shallow rung, and during an isolated finger-strength test. Lead-climbing and bouldering performance were also measured, along with an intermittent forearm endurance test. The pre-to-post changes were not significantly different between the groups for any of the parameters (P = 0.062–0.710). However, both the BCT (ES = 0.30, P = 0.049) and LCT (ES = 0.41, P = 0.046) groups improved strength in the isometric pull-up performed using the jug, whereas neither group improved force in the rung condition (P = 0.054 and P = 0.084) or RFD (P = 0.060 and P = 0.070). Furthermore, climbing and bouldering performance remained unchanged in both groups (P = 0.210–0.895). The LCT group improved forearm endurance (ES = 0.55, P = 0.007), while the BCT group improved isolated finger strength (ES = 0.35, P = 0.015). In addition to isometric pull-up strength, bouldering can increase isolated finger strength while lead-climbing may improve forearm endurance. A 5-week period prioritizing one discipline can be safely implemented for advanced to intermediate climbers without risking declined performance in the non-prioritized discipline.

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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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