电肌肉刺激（EMS）技术自19世纪初商业化以来历经起伏，如今广泛应用于复健医疗及体能训练领域。其原理是在运动时透过电脉冲刺激肌肉，短时间内产生数千次肌肉收缩，远超传统训练所能达到的次数。目前市面上已有多家公司推出家用EMS训练衣，其中德国品牌Pepper以1,400美元的价格提供最平价的选择，号称穿著该套装运动20分钟即可达到传统一小时训练的热量消耗与肌肉激活效果。
针对EMS的科学研究结果喜忧参半但整体偏向乐观。2021年一项统合分析发现EMS对肌肉量与力量有显著正面效果，但对体脂肪减少无明显帮助；2023年的研究则指出，八周持续阻力训练结合每日EMS可显著增加肌肉量并降低体脂率。然而医学界对此尚未形成共识：有医师认为EMS主要适用于复健患者，也有NFL队医将其纳入自身训练辅助，多数专家建议将EMS视为传统力量训练的补充而非替代。
作者亲身穿著Pepper套装进行了为期两个月、每周三次的测试体验。过程中他发现汗水会大幅影响导电性进而改变刺激强度，腹部肌肉对电击最为敏感，且套装的应用程式偶有故障。两个月后，数据显示他增加了2.7磅肌肉、减少了1.6磅脂肪，手臂、大腿和胸围各增加半吋以上，力量也有所提升，但腰围未见改善。作者认为EMS确实对其体能产生了一定正面影响，计划继续使用但将频率降至每周两次。
Electrical muscle stimulation (EMS) has been commercially available since the early 19th century and is now used in both rehabilitative medicine and fitness training. The technology works by delivering electrical pulses to muscles during exercise, generating thousands of contractions far beyond what traditional repetitions can achieve. Several companies now offer home-use EMS suits, with German brand Pepper providing the most affordable option at $1,400, claiming that a 20-minute suited workout equals an hour of conventional exercise in caloric burn and muscle activation.
Scientific research on EMS is extensive but mixed, though generally optimistic. A 2021 meta-study found significant positive effects on muscle mass and strength but not on body fat, while a 2023 study showed that eight weeks of resistance training combined with daily EMS significantly improved muscle mass and reduced body fat percentage. Medical opinions range widely: some physicians see EMS as beneficial mainly for rehabilitation patients, while others, including an NFL team doctor, incorporate it into their own training. The prevailing expert consensus is that EMS should complement traditional strength training rather than replace it.
The author tested the Pepper suit over two months with three sessions per week alongside his regular exercise routine. He discovered that sweat dramatically affects electrical conductivity and shock intensity, that abdominal muscles are especially sensitive to stimulation, and that the app occasionally glitched. After the trial period, his data showed a gain of 2.7 pounds of muscle, a loss of 1.6 pounds of fat, increases of half an inch or more in biceps, thigh, and chest circumference, and modest strength improvements, though his waistline remained unchanged. He concluded that EMS likely contributed positively to his fitness gains and plans to continue using the suit at a reduced frequency of twice per week.