An exploration of muscle oxygen kinetics in professional boxing

Abstract

The investigation into the physiological aspects of boxing has predominantly focused on the systemic responses observed in amateur athletes, with the unique challenges of professional boxing, particularly given its distinct competition structure, receiving less attention. This thesis aimed to explore the physiological reactions to various professional boxing training modalities and assess the impact of training interventions and environmental changes on performance outcomes.

In Study 1, the peripheral response of the rectus femoris muscle was investigated using NIRS wearable technology to determine the physiological demands of typical training modalities and a repeated sprint protocol in a sports science setting. 10 experienced professional boxers (age: 26±5 years, height: 177±4 cm, weight: 71±6 kg) on different days completed 6 x 3 minute rounds of pad, bag or spar-based training with 1 minute recovery time between each round, and on a separate occasion underwent lower body repeated Wingate trials, trials consisting of two, 30 second efforts against resistance (lower body 7.5%) with a 60 second active recovery. Heart rate monitors and NIRS devices were utilised to record heart rate and muscle oxygenation. Study one revealed a new biological model of skeletal muscle oxygenation within boxing, suggesting 3 phases for initial onset of exercise (time delay, fast desaturation and recovery) and a 3 phase recovery (time delay, fast resaturation, and slow recovery. Significant increases across rounds in the desaturation delay (p=0.016), rate of rapid desaturation (p<0.001), and duration of rapid desaturation (p=0.019) were noted. A notable difference in heart rate and skeletal muscle oxygenation changes during sparring compared to pad or bag sessions (p<0.001), punch count disparities between modalities (p<0.001), and significant correlations between average power (p<0.001) and desaturation rates in the left rectus femoris during the first lower Wingate trial (p<0.05) were observed. This study suggests that current training methods may not optimally prepare boxers for competition.

Study 2 examined mitochondrial rate changes following a three-week self-directed sprint protocol in nine male professional boxers. Nine male professional boxers (age: 26±5 years, height: 177±4 cm, weight: 71±6 kg) participated in a pre-post study design. The protocol included an occlusion protocol to assess mitochondrial rate changes and an incremental treadmill test to volitional exhaustion. Between the second and third sessions, the athletes undertook a repeated Wingate protocol comprising three 30-second maximal sprints with 60-second recovery periods, repeated three times weekly. There was a significant main effect for time in incremental time to exhaustion (p=0.004), There was a significant difference in time to exhaustion following the 3-week sprint interval training protocol between session 1 and 3 (session 1: 662 ± 100 s, session 3: 702 ± 106 s, p=0.023) and session 2 and 3 (session 2: 651 ± 107 s, session 3: 702 ± 106 s, p=0.001). Significant improvements in time to exhaustion were observed following the sprint interval training, indicating the effectiveness of high-intensity training (HIT) in enhancing physiological adaptations in well-trained individuals, evidenced by increased run time duration, higher SmO2 at exhaustion, and improved mitochondrial rates post-intervention.

Study 3 investigated the impact of heat on performance, recognising the common scenario where boxers transition from changing areas to competition areas with varying temperature conditions. Ten male professional boxers (age 27.22 ± 6.35, height, 175 ± 5.81 cm, weight 71.82 kg ± 5.12, body fat percentage 9.97 ± 2.72 kg) participated in a pre-post study design. The study consisted of participants undergoing repeated Wingate’s, 4 x 30 seconds with 60 second recovery, in both temperate conditions and hot conditions (35 degrees Celsius with 40 percent humidity). While significant effects were noted for Peak and Average Power and maximum Heart Rate within sprints (p<0.001), no significant interaction between sprint and temperature was found (p>0.05). Subtle changes were observed in the time to rapid desaturation across sprints in hot conditions, indicating that even short-term heat exposure can affect power output, muscle oxygenation, and localized sweat rates, essential factors in competition preparation.

Date of Award	4 Nov 2024
Original language	English
Awarding Institution	Abertay University
Supervisor	John Babraj (Supervisor), Ashley Williams (Supervisor) & Graeme Sorbie (Supervisor)