## 3 Results
### Variables Analyzed and Data Collection  
The selected studies analyzed various variables to evaluate the effects of the interventions. Twelve articles assessed punching performance [19, 20, 21, 22, 23, 60, 62, 63, 64, 65, 66, 68], specifically two studies evaluated punching force through a device (Kiktest-100, Moscow, Russia) consisting of a standard punching bag with a dynamometer and sensor inside [20, 36]. Four articles evaluated the impact force of striking through a vertically mounted force platform [59, 63, 64, 65, 66]. [PERSON] et al. [63] used a force platform (AccuPower; AMTI, Graz, Austria) mounted on a wall that sampled at a frequency of 2000 Hz. [PERSON] et al. [65] mounted a force platform (Kistler, Winterthur, Switzerland, model 9287B) on a steel frame recording data with a sampling rate of 1000 Hz. [PERSON] et al. [59, 66] used a force platform (Bertec, Columbus, OH, USA) mounted on a custom-made steel apparatus recording data with a sampling rate of 2000 Hz. On the other hand, [PERSON] et al. [19] and [PERSON] [21] measured punch speed and power using a stroboscope (107-104 Hz), three axial acceleration sensors (model 4630, Measurements Specialties, Hampton, VA, USA) and a Sony HDR-CX630E 4K digital camera. [PERSON] et al. [68] used the \"Tendo Power and Speed Analyzer\" device (Lexington, USA) to detect the punching speed of boxers. [PERSON] et al. [60] calculated the punching speed with 29 reflective markers fixed on body reference points ([PERSON] model) and 10 high-speed infrared cameras with a frequency of 250 Hz (Motion Analysis System, Rohnert Park, CA, USA), and they additionally attached a triaxial accelerometer (Model SS34L, BIOPAC System, CA, USA) with a sampling rate of 3000 Hz to the target manikin. [PERSON] et al. [64] used a professional boxing transducer (Strike Tec Boxing Sensors, Strike Tec, Dallas, TX, USA; version 1.4.4) with a mobile application to measure the punch force and punch speed calculated from the acceleration. Finally, [PERSON] et al. [62] determined the number of punches and average punches per round, through combat videos that were presented to three international judges from the international flagship (2 Star). Regarding muscle strength assessments, [PERSON] et al. [19] assessed upper and lower limb maximal strength using a multifunction dynamometer (ACE-2000, Ariel Dynamics Inc., Coto de Caza, CA, USA). In addition, they assessed trunk strength using an isokinetic dynamometer (Humac Norm, Stoughton, MA, USA). One study [68] measured handgrip strength using a Takei Kiki Kogya hand dynamometer (Takei Scientific Instruments Co., Ltd., Tokyo, Japan). [PERSON] et al. [18, 63], [PERSON] et al. [22] and [PERSON] et al. [61] measured muscle power through a T Force linear position transducer (Dynamic Measurement System; Ergotech Consulting S.L., Murcia, Spain) and GymAware Powertool (Kinetic Performance Technologies, Canberra, Australia). Five studies assessed neuromuscular performance using vertical jump [22; 59; 65; 66; 68]. [PERSON] et al. [68] measured vertical jump with the Squat Bounce Test using the Opto Jump Next(r) device (Microgate, Bolzano, Italy). [PERSON] et al. [60] assessed the countermovement jump using two force platforms (AMTI, Inc., Newton, MA, USA) with a sampling rate of 1000 Hz. [PERSON] et al. [22] measured the SJ and CMJ using a contact platform (Elite Jump(r), S2 Sports, Sao Paulo, Brazil). [PERSON] et al. [59; 66] assessed CMJ using a photocoll system (Optojump, Microgate, Bolzano, Italy). Conversely, [PERSON] [21] assessed speed strength by throwing a solid ball and the 15 s fast push-up test, and they also designed an athletic fitness index for boxers composed of sprint tests, vertical and horizontal jumps, hand grip strength, medicine ball throw, abdominal crunches and tapping tests of 5 s and 30 s. Finally, they measured the level of movement capacity through deep squats, front and back lunges, straight-knee leg raises, shoulder joint flexibility, push-ups and rotational stability. [PERSON] et al.