TY - JOUR
T1 - Reduced rate of force development under fatigued conditions is associated to the decline in force complexity in adult males
AU - D’Emanuele, Samuel
AU - Boccia, Gennaro
AU - Angius, Luca
AU - Hayman, Oliver
AU - Goodall, Stuart
AU - Schena, Federico
AU - Tarperi, Cantor
PY - 2024/7/24
Y1 - 2024/7/24
N2 - PurposeThis study aimed to verify whether the slowing of muscle contraction quickness, typically observed in states of fatigue, may worsen force control by decreasing the rate with which force fluctuations are modulated. Therefore, we investigated the relationship between rate of force development (RFD), and force fluctuations' magnitude (Coefficient of variation, CoV) and complexity (Approximate Entropy, ApEn; Detrended fluctuation analysis, DFAα).MethodsFourteen participants performed intermittent ballistic isometric contractions of the plantar dorsiflexors at 70% of maximal voluntary force until task failure (under 60% twice).ResultsIndices of RFD (RFDpeak, RFD50, RFD100, and RFD150) decreased over time by approximately 46, 32, 44, and 39%, respectively (p all ≤ 0.007). DFAα increased by 10% (p < 0.001), and CoV increased by 15% (p < 0.001), indicating decreased force complexity along with increased force fluctuations, respectively. ApEn decreased by just over a quarter (28%, p < 0.001). The linear hierarchical models showed negative associations between RFDpeak and DFAα (β = − 3.6 10–4, p < 0.001), CoV (β = − 1.8 10–3, p < 0.001), while ApEn showed a positive association (β = 8.2 × 10–5, p < 0.001).ConclusionThe results suggest that exercise-induced reductions in contraction speed, lead to smoother force complexity and diminished force control due to slower adjustments around the target force. The fatigued state resulted in worsened force producing capacity and overall force control.
AB - PurposeThis study aimed to verify whether the slowing of muscle contraction quickness, typically observed in states of fatigue, may worsen force control by decreasing the rate with which force fluctuations are modulated. Therefore, we investigated the relationship between rate of force development (RFD), and force fluctuations' magnitude (Coefficient of variation, CoV) and complexity (Approximate Entropy, ApEn; Detrended fluctuation analysis, DFAα).MethodsFourteen participants performed intermittent ballistic isometric contractions of the plantar dorsiflexors at 70% of maximal voluntary force until task failure (under 60% twice).ResultsIndices of RFD (RFDpeak, RFD50, RFD100, and RFD150) decreased over time by approximately 46, 32, 44, and 39%, respectively (p all ≤ 0.007). DFAα increased by 10% (p < 0.001), and CoV increased by 15% (p < 0.001), indicating decreased force complexity along with increased force fluctuations, respectively. ApEn decreased by just over a quarter (28%, p < 0.001). The linear hierarchical models showed negative associations between RFDpeak and DFAα (β = − 3.6 10–4, p < 0.001), CoV (β = − 1.8 10–3, p < 0.001), while ApEn showed a positive association (β = 8.2 × 10–5, p < 0.001).ConclusionThe results suggest that exercise-induced reductions in contraction speed, lead to smoother force complexity and diminished force control due to slower adjustments around the target force. The fatigued state resulted in worsened force producing capacity and overall force control.
KW - Entropy
KW - Force complexity
KW - Rapid force
KW - Steadiness
UR - http://www.scopus.com/inward/record.url?scp=85199395078&partnerID=8YFLogxK
U2 - 10.1007/s00421-024-05561-9
DO - 10.1007/s00421-024-05561-9
M3 - Article
AN - SCOPUS:85199395078
SN - 1439-6319
SP - 1
EP - 9
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
ER -
