Even though HIFT and CrossFit programs have been lauded for their potential to improve fitness in a range of qualities, a recent meta-analysis has reported that might not be the case. The authors have found a high risk of bias and a low level of evidence for almost all the included studies and pointed that an improvement in the quality of these studies is necessary so that such training modalities can be critically evaluated in regard to their effectiveness and safety. The only consistent and significant finding of the review is that CrossFit fosters a good training environment, with participants reporting a higher level of sense of community, satisfaction, and motivation during training. No changes were found for body composition, body mass index, relative body fat, fat mass, lean body mass, and waist circumference. In addition, the performance of cardiovascular and resistance training exercises within the same program has been termed as concurrent training, and while much controversy still exists, there appears to be an interference effect that inhibits gains in strength when high levels of aerobic exercise are performed concomitantly.
However, strength training studies in endurance athletes have shown positive results in improving performance in both types of exercise. In addition, the detrimental effects of concurrent training are less pronounced in untrained individuals, and when training frequency is low (2 – 3 sessions per week). Therefore, although an interference effect could hinder some gains in strength, this would not pose a problem to rock climbers, as training volume would be low, and the level of strength and endurance necessary to compete at the high level in the sport are much different than of those in specific endurance or strength events.
High intensity functional training is a modality that involves the use of functional exercises, often combined with intense cardiovascular activities that has the potential to stimulate different systems in the body in a balanced and integrated manner. Current research has shown that HIFT can lead to improvements in strength, aerobic and anaerobic fitness, improvements and body composition, flexibility, work capacity and performance. While no intervention studies have been performed in athletes yet, HIFT could be a time-efficient strategy particularly for those activities that require multiple fitness characteristics for performance. In this context, it appears that rock climbers could benefit from adding HIFT to their training programs, particularly during the off-season and pre-season, to increase overall work capacity and movement economy. Particularly, climbing athletes could perform sessions that are focused on weightlifting and gymnastics, with exercises that would further stress the major muscle groups required for climbing.
In addition, when training parameters are properly manipulated, such sessions can also generate a significant metabolic stress assisting athletes in achieving a high level of aerobic and anaerobic fitness, while maintaining optimal body composition. Coaches should understand that HIFT can generate significant levels of fatigue and a high overall training load. Therefore, sessions should be planned according to the goals of the specific training phase, so that enough recovery is provided between training sessions. Nevertheless, HIFT can be a safe and effective tool that has the potential to significantly influence climbing performance in recreational and elite level athletes.