等長肌力與最大攝氧量：肌力與有氧能力間之潛在關聯性

Isometric muscular strength and maximal oxygen uptake: The potential relationship between muscular strength and aerobic capacity

緒論：最大攝氧量（maximal oxygen uptake, V‧O2max）受運動時所涉及的肌群數量和疲勞進展影響。先前研究指出，較高的肌力（muscular strength）可能有助於增強抗疲勞（fatigue resistance）能力，這意味著，肌力可能對V‧O2max有潛在影響。然而，當涉及相似肌群時，肌力與V‧O2max之間的關係仍不明確。本研究旨在探討測驗中涉及相似肌群時，肌力與V‧O2max之間的相關性。方法：40名健康男性大學生分別在不同天進行大腿中段等長上拉（isometric mid-thigh pull, IMTP）測驗，以及腳踏車遞增負荷測驗（graded exercise test, GXT）。在IMTP中，參與者被測量力量峰值（peak force, PF）、5秒平均力量（5-second mean force, MF）、最大發力率（maximal rate of force development, RFDmax），與0–30、0–90、0–150、0–200和0–250毫秒內的分段RFD。而GXT則測量V‧O2max、最大心跳率（maximal heart rate, HRmax）和最大功率輸出（peak power output, Wpeak）。完成測驗後，以PF（1940 N）和MF（1938 N）的中位數（median），將參與者分為高肌力組（high muscular strength group, GHSPF; GHSMF）和低肌力組（low muscular strength group, GLSPF; GLSMF）。結果：整體數據顯示，PF與V‧O2max（r = 0.32, R²= 0.10, p < .05），以及MF與V‧O2max（r = 0.32, R²= 0.10, p < .05）之間皆存在顯著相關性。而所有RFD指標均與V‧O2max無顯著相關性（p > .05）。關於肌力水準對GXT數據之影響，GHSPF和GHSMF之V‧O2max（GHSPF vs. GLSPF, 3.51±0.41 vs. 3.19±0.44 L/min, t = 2.44, p < .05; GHSMF vs. GLSMF, 3.53±0.41 vs. 3.17±0.43 L/min, t = 2.74, p < .05）與Wpeak（GHSPF vs. GLSPF, 228±33 vs. 204±28 W, t = 2.16, p < .05; GHSMF vs. GLSMF, 229±32 vs. 206±28 W, t = 2.24, p< .05）皆分別顯著高於GLSPF和GLSMF，而HRmax在GHS和GLS間無顯著差異（p> .05）。然而，在具有相似PF/MF的參與者中，V‧O2max的差異可高達76%。結論：儘管肌力與V‧O2max之間具相關性，但肌力僅解釋10%的V‧O2max變異量。也就是說，即便運動所涉及的肌群相似，肌力可能不是決定V‧O2max的關鍵因素。

Introduction: Maximal oxygen uptake (V‧O2max) is influenced by the amount of muscle group involved and the progression of fatigue during exercise. Previous studies suggested that greater muscular strength may enhance fatigue resistance, which could imply a potential influence on V‧O2max. However, the relationship between muscular strength and V‧O2max remains unclear, especially when similar muscles are involved. This study aimed to explore the correlation between muscular strength and V‧O2max when similar muscle groups are engaged during testing. Methods: Forty healthy male college students completed isometric mid-thigh pull (IMTP) and cycling graded exercise test (GXT) on different days. In IMTP, participants’peak force (PF), 5-second mean force (MF), maximal rate of force development (RFD), and RFD within 0–30, 0–90, 0–150, 0–200, and 0–250 milliseconds during IMTP were measured. Meanwhile, V‧O2max, maximal heart rate (HRmax), and peak power output (Wpeak) were collected during GXT. Participants were categorized into high (GHSPF and GHSMF) and low (GLSPF and GLSMF) muscular strength groups based on the median PF (1940 N) and MF (1938 N). Results: Significant relationships were found between PF and V‧O2max (r = 0.32, R²= 0.10, p < .05), and between MF and V‧O2max (r = 0.32, R²= 0.10, p < .05) in the pooled data. There was no significant relationship between V‧O2max and any of RFD parameters (p > .05). Regarding the influence of muscular strength levels on GXT parameters, both V‧O2max (GHSPF vs. GLSPF, 3.51±0.41 vs. 3.19±0.44 L/min, t = 2.44, p < .05; GHSMF vs. GLSMF, 3.53±0.41 vs. 3.17±0.43 L/min, t = 2.74, p < .05) and Wpeak (GHSPF vs. GLSPF, 228±33 vs. 204±28 W, t = 2.16, p < .05; GHSMF vs. GLSMF, 229±32 vs. 206±28 W, t = 2.24, p < .05) were significantly higher in GHSPF and GHSMF than those in GLSPF and GLSMF, while there was no difference between GHS and GLS on HRmax (p >.05). However, a large variation in V‧O2max (up to 76%) was observed among participants with similar PF/MF. Conclusion: Although muscular strength was significantly correlated with V‧O2max, muscular strength explained only 10% of the variance in V‧O2max. This suggests that even if the muscle groups involved in the exercise are similar, muscular strength might not be a key factor in determining V‧O2max.