Spring 2026
What tactical athletes need to know about EPOC and afterburn
Exercise requires a lot of oxygen. The longer and harder a workout session is, the more oxygen the body needs. During recovery, oxygen uptake can remain elevated above resting levels for several minutes or hours; this is called excess postexercise oxygen consumption (EPOC).
EPOC is the elevation in oxygen uptake and energy expenditure following exercise compared with the baseline state (Gaesser & Brooks, 1984). In a state of EPOC, the body replenishes oxygen in the blood and muscles, creates more ATP (an essential energy molecule) and increases the rates of triglyceride-fatty acid cycling, protein turnover, body temperature, circulation and ventilation. These metabolic processes are essential for the body to return to homeostasis. During this time, the body continues to burn calories, which tactical athletes may find beneficial, especially for those looking to lose weight.
In general, there are numerous ways tactical athletes can design and manipulate their training programs. For example, changing the number of training days per week manipulates frequency or changing the exercises done in the training session changes the type. However, literature has demonstrated that reaching an intensity of >50-60 percent VO2max is crucial for inducing EPOC. Exercise sessions that achieve this intensity appear to promote EPOC (Børsheim & Bahr, 2003; LaForgia et al., 2006), highlighting exercise intensity as the most important training variable for eliciting EPOC.
During recovery, oxygen uptake can remain elevated above resting levels for several minutes or hours; this is called excess postexercise oxygen consumption, or EPOC.
EPOC research is one of the most compelling areas of exercise science. Sindorf et al. (2021) focused on high-intensity interval training (HIIT) and EPOC. HIIT involves brief repeated bouts of high-intensity exercise with intermittent recovery periods. That report found that HIIT induced EPOC for up to 30 minutes post-training. Additionally, during the 30-minute EPOC, participants had increased rates of carbohydrate and fat oxidation. Interestingly, the duration of the rest period did not appear to affect reaching a state of EPOC. This study helped reaffirm that intensity is how tactical athletes achieve “afterburn.”
Achieving EPOC also might help tactical athletes achieve their weight-loss goals. Researchers compared HIIT and continuous, moderate-intensity training and found HIIT slightly more efficient at eliciting EPOC in the post-training state. Specifically, HIIT induced EPOC for the first 10 minutes after training but was comparable to continuous, moderate-intensity training thereafter. Also, HIIT demonstrated greater efficiency in fat metabolism, making it ideal for those trying to lose weight (Jiang et al., 2024). HIIT is still considered one of the best weight-loss programs due to its time efficiency with the added bonus of some calorie-burning on the back end.
Initially, it was thought that aerobic training could induce EPOC better than resistance training (Børsheim & Bahr, 2003), but more recent research challenges this idea. Greer et al. (2021) examined fit women and had them do a standard weightlifting protocol (i.e., resistance training) and a HIIT protocol (see below). Participants were considered aerobically fit and experienced weightlifters (trained at least two days per week for the past six months).
Greer et al. (2021) analyzed the participants’ resting metabolic rates at the 14- and 24-hour time points. Overall, the HIIT protocol showed that both training protocols resulted in significant elevations in energy expenditure at the 14-hour mark but not at 24 hours. The primary findings of this study are that both a 30-minute resistance training session and a 30-minute HIIT treadmill session result in a significant increase in energy expenditure, detectable up to 14 hours later, in moderately trained women.
While HIIT is the most effective for initiating EPOC, are there any other methods available for time-strapped tactical athletes? Sun et al. (2024) compared moderate-intensity continuous exercise (CE), high-intensity interval exercise (IE) and accumulated exercise (AE). Most will be familiar with CE and IE (i.e., HIIT) but AE is a strategy that involves performing short, moderate-to-high intense exercises multiple times throughout the day. All groups used a stationary bike for the study.
In short, AE showed higher metabolic benefit for EPOC than CE or IE. EPOC duration ranged from 13-20 minutes across exercise protocols (i.e., CE, IE, AE). However, AE had the longest EPOC duration of ~41 minutes, accounting for all EPOC states added together. For tactical athletes, multiple shorter exercise sessions (10-15 minutes each) may yield significant benefits by the end of the day. For busy schedules, understanding how shorter, accumulated sessions can maximize EPOC offers practical options to enhance calorie burn without lengthy workouts. In other words, the “accumulated exercise” method may prove to be greater than the sum of its parts regarding EPOC.
Tactical athletes designing programs for themselves or their team should consider the intensity of the training sessions as it is the gateway to eliciting EPOC.
While some of the EPOC science looks promising, this area of exercise research remains controversial. First, there is a lack of long-term training studies, leading to questions about weight management through manipulation of exercise program variables. Second, it remains unclear whether exercise mode affects EPOC. Third, while resistance training tends to be more effective for achieving EPOC, further investigation is warranted to understand how that connects to long-term weight management. Fourth, EPOC is also more pronounced in untrained individuals than in fit individuals, leaving the scientific community unsure what it will take for high-tier athletes to achieve the same rate of calorie burning after a training session (Greer et al., 2021).
Tactical athletes designing programs for themselves or their team should consider the intensity of the training sessions as it is the gateway to eliciting EPOC. Regardless of the duration or frequency of an athlete’s training, if their individual sessions are not intense (i.e., close to VO2max), they will not elicit the required oxygen deficit for EPOC.
According to the research, EPOC is not the silver bullet for metabolic superiority or weight loss that it is often considered to be. EPOC does provide a modest amount of energy expenditure during critical recovery hours post-training, but it should be considered a bonus rather than the goal. Despite this, tactical athletes are encouraged to try different training modalities and find one that helps them achieve their goals. Ultimately, tactical athletes should prioritize consistently high-intensity, sustainable training approaches, using EPOC as a supplemental benefit rather than the primary objective of their programming.
