Department of Intervention Research in Exercise Training, German Sport University Cologne, Cologne, Germany.
PeerJ. 2022 May 18;10:e13333. doi: 10.7717/peerj.13333. eCollection 2022.
Acute increases in exercise-induced oxygen uptake (V̇O) is crucial for aerobic training adaptations and depends on how much muscle mass is involved during exercising. Thus, handcycling is per se limited for higher maximal oxygen uptakes (V̇Omax) due to restricted muscle involvement. Handcycling with additional and simultaneous application of low-frequency electromyostimulation (EMS) to the lower extremities might be a promising stimulus to improve aerobic capacity in disabled and rehabilitative populations.
Twenty-six healthy young adults (13 female, age: 23.4 ± 4.5 years, height: 1.77 ± 0.09 m, mass: 71.7 ± 16.7 kg) completed 4 ×10 minutes of sitting (SIT), sitting with concurrent EMS (EMS_SIT), handcycling (60 rpm, 1/2 bodyweight as resistance in watts) (HANDCYCLE) and handcycling with concurrent EMS of the lower extremities (EMS_HANDCYCLE). During EMS_SIT and EMS_HANDCYCLE, low frequency EMS (impulse frequency: 4Hz, impulse width: 350 µs, continuous stimulation) was applied to gluteal, quadriceps and calf muscles. The stimulation intensity was selected so that the perceived pain could be sustained for a duration of 10 minutes (gluteus: 80.0 ± 22.7 mA, quadriceps: 94.5 ± 20.5 mA, calves: 77.5 ± 19.1 mA).
Significant mode-dependent changes of V̇O were found ( < 0.001, = 0.852). Subsequent post-hoc testing indicated significant difference between SIT EMS_SIT (4.70 ± 0.75 10.61 ± 4.28 ml min kg, < 0.001), EMS_SIT HANDCYCLE (10.61 ± 4.28 13.52 ± 1.40 ml min kg, = 0.005), and between HANDCYCLE EMS_HANDCYCLE (13.52 ± 1.40 18.98 ± 4.89 ml min kg, = 0.001).
Handcycling with simultaneous lower body low-frequency EMS application elicits notably higher oxygen uptake during rest and moderately loaded handcycling and may serve as an additional cardiocirculatory training stimuli for improvements in aerobic capacity in wheelchair and rehabilitation settings.
运动诱导的摄氧量（V̇O）的急性增加对于有氧训练适应至关重要，这取决于运动过程中涉及多少肌肉量。因此，由于受限于参与运动的肌肉量，手摇车本身对于更高的最大摄氧量（V̇Omax）的提升是有限的。对手摇车施加低频电肌肉刺激（EMS）以同时刺激下肢可能是一种很有前途的刺激方式，可以提高残疾人和康复人群的有氧能力。
26 名健康的年轻成年人（13 名女性，年龄：23.4 ± 4.5 岁，身高：1.77 ± 0.09 m，体重：71.7 ± 16.7 kg）完成了 4 次 × 10 分钟的坐姿（SIT）、坐姿时同时进行 EMS（EMS_SIT）、手摇车（60 rpm，1/2 体重作为阻力，以瓦特为单位）（HANDCYCLE）和手摇车同时进行下肢低频 EMS（EMS_HANDCYCLE）。在 EMS_SIT 和 EMS_HANDCYCLE 中，低频 EMS（脉冲频率：4Hz，脉冲宽度：350 μs，连续刺激）施加于臀肌、股四头肌和小腿肌肉。刺激强度选择为可以持续 10 分钟的可感知疼痛强度（臀肌：80.0 ± 22.7 mA，股四头肌：94.5 ± 20.5 mA，小腿：77.5 ± 19.1 mA）。
发现模式依赖性的 V̇O 显著变化（ < 0.001， = 0.852）。随后的事后检验表明，SIT 和 EMS_SIT（4.70 ± 0.75 10.61 ± 4.28 ml min kg， < 0.001）、EMS_SIT 和 HANDCYCLE（10.61 ± 4.28 13.52 ± 1.40 ml min kg， = 0.005）以及 HANDCYCLE 和 EMS_HANDCYCLE（13.52 ± 1.40 18.98 ± 4.89 ml min kg， = 0.001）之间存在显著差异。
手摇车同时施加下肢低频 EMS 会引起休息和中等负荷手摇车时明显更高的摄氧量，在手摇车和康复环境中可能作为提高有氧能力的额外心血管训练刺激。
