🎮 An hour of competitive gaming burns about as many extra calories as a single fish cake. That is the number Japanese gaming press pulled out of a new systematic review. But the same review found heart rates climbing from 85 to 137 beats per minute in ten minutes. Two measurements, one body, and an argument about the word "sport" that refuses to die.

Five studies. That was all there was.

On July 8, 2026, a team led by Jiří Kotas at Masaryk University in Brno, Czech Republic, published a systematic review in Sports Medicine - Open titled "Energy Expenditure of Esports Athletes During Gameplay." Six researchers set out to answer a narrow question: how much energy do competitive players actually burn while they play?

The method was unglamorous. They searched PubMed, Embase, SPORTDiscus, Web of Science and Scopus on January 29, 2025, pulled 176 records, and then started cutting. Out went the duplicates, the non-English papers, the conference abstracts and the book chapters, along with the papers that turned out not to measure energy expenditure during a session.

Five studies survived. The protocol was pre-registered with PROSPERO (CRD42025644801) and followed PRISMA 2020 reporting standards, which is to say the procedure was rigorous. The material was thin.

Most of the surviving work used indirect calorimetry: mask on, measure the oxygen going in and the carbon dioxide coming out, and back-calculate the energy burned. The games covered League of Legends, Dota 2, CS:GO, Overwatch, Paladins and FIFA, spanning MOBAs, shooters and sports sims. Almost all the participants were amateurs, and only one of the five studies looked at expert competitors.

The calories barely move

Energy expenditure during gameplay clustered between 1.3 and 2.5 kcal per minute. That is the range the review's authors describe as light physical activity, and at the low end, indistinguishable from simply sitting.

The individual results scatter more than that summary suggests. Nicholson and colleagues, the team that studied the experts, recorded a median of 1.28 kcal per minute at rest against 1.45 during competitive play, a rise of roughly 17 percent that cleared statistical significance at p = 0.02. Kocak, working with eleven amateur men playing MOBAs, found about 40 percent more energy burned, or roughly 1.9 METs, and also spotted a positive correlation between a player's actions per minute and their metabolic load. The busier the hands, the higher the number.

Then there is Zimmer and colleagues, who put 30 amateurs through a 30-minute session and found essentially nothing. There was no significant change in energy expenditure, none in oxygen consumption, and no detectable stress response. Heart rate actually drifted downward toward the end, which the reviewers read as habituation or reduced engagement.

Ketelhut and Nigg landed in between, measuring MET values of 1.6 to 2.0 during play. A MET is a measure of activity intensity that treats sitting at rest as 1, so two METs is roughly what washing dishes costs you.

The Japanese site AUTOMATON did the arithmetic that made the story travel: take the largest gap in the dataset, stretch it across an hour, and you get about 41 extra calories. In Japan that is one chikuwa, the tube-shaped fish cake sold in every supermarket, or one mandarin orange, or four or five potato chips. Nobody is losing weight this way.

The heart rate tells a different story

Every study that measured heart rate found it going up, and in one case dramatically.

Haupt and colleagues watched a player's pulse climb from roughly 85 bpm at rest to roughly 137 bpm within the first ten minutes and stay elevated. Ventilation rose about 50 percent. Oxygen consumption, meanwhile, did not budge, while the same subject on a cycle ergometer pulled an extra 0.6 litres of oxygen per minute.

Across the studies, blood glucose and cortisol went up and heart rate variability went down, a signature the authors read as sympathetic nervous system activation driven by psycho-emotional stress rather than physical work. They compare the pattern to competitive driving or sitting a difficult exam.

Two cautions belong here, and the review states both. Haupt's study is a single-case report, one person, which is a vivid anecdote rather than a population finding. And Nicholson's experts, measured under the full set of best-practice controls, showed a much more modest shift, from a median of 84.5 to 87.1 bpm. The dramatic number that will end up in headlines comes from the smallest study in the set, and the only one that reported no pre-measurement controls at all.

What survives the caveats is the dissociation itself: the cardiovascular system reacts, the metabolism does not follow.

Why the Japanese argument is a different argument

When the story ran in Japan, the comment threads went after something other than the numbers. They went after the word.

Japanese borrowed supōtsu from English but received it through the school system, where it arrived fused with taiiku, physical education. Several commenters made the point directly: in Japanese, "sport" carries an obligatory smell of gym class and sweat, whereas the English word descends from disport, meaning diversion or pastime, and has always covered competition without much movement. Shooting is a sport. So are billiards and darts, which the standard reference table for physical activity rates at 2.5 METs, not far off the 1.6 to 2.0 measured for esports. Archery, usually lumped in with them, sits at 4.3 METs on that same table, which is moderate exercise. An excited spectator comes in at 3.3, above the players.

The legal text backs the intuition. Japan's Basic Act on Sport, passed in 2011, defines sport in its preamble as athletic competition and other physical activity, undertaken for the sound development of mind and body.

Which means the Japanese-language debate is partly a translation problem wearing a physiology costume. Asked in Japanese, the question is whether esports belongs in PE class. Asked in English, it is whether esports is an organised competition, and the answer to that one is obviously yes.

The institutions did not wait for an answer

Japan's governing body joined the Japanese Olympic Committee as an associate member on June 11, 2024, on a term-limited basis running to the end of March 2027, specifically to send athletes to international multi-sport events. It joined the Japan Sport Association as an approved organisation on June 25, 2025, and renamed itself JESU, the Japan Esports Union, on August 1 that year. Esports now sits inside the same institutional furniture as judo and track.

The immediate consequence arrives in weeks. The 20th Asian Games run in Aichi and Nagoya from September 19 to October 4, 2026, and esports is a full medal event: 11 disciplines across 13 titles, staged in Hall D of Aichi Sky Expo from September 23 to October 2, with Japan entering 7 disciplines and 9 titles.

The Olympic track has gone the other way. The IOC Session approved the creation of the Olympic Esports Games unanimously in July 2024, but the Saudi partnership behind them collapsed in late 2025, the planned 2027 Riyadh edition was cancelled, and in May 2026 Kyodo News reported that the IOC Esports Commission itself had been put on hiatus. As of August 2026 there is no host, no title list and no date.

That same IOC recognised the international chess federation as a sports federation back in June 1999, on the grounds that structured competition, not perspiration, is what defines a sport. Chess has still never been an Olympic medal event. And in November 2026, at the Esports Nations Cup in Riyadh, the Saudi-run tournament launched outside the Olympic framework, chess will be competing as one of 16 esports titles.

What the researchers are actually worried about

Read the review's conclusion and the sport question turns out to be a side door. The authors' concern is health.

Gameplay does not meet the threshold for physical activity that produces health benefits, so it cannot be counted toward anyone's exercise. At the same time it delivers repeated, prolonged psycho-emotional stress, sustained across long hours in a chair. Low metabolic demand plus high sympathetic arousal plus a sedentary posture is not a neutral combination, and the paper argues it may carry cardiometabolic risk that nobody is currently tracking.

What they want, concretely, is compensatory physical training built into player routines and individualised nutrition plans that account for the mismatch. They also want better studies. Nobody has yet measured an elite player mid-tournament, under real pressure, which is precisely where the effect should be largest and where Bluetooth restrictions make measurement nearly impossible.

The science does not resolve the question, and was never going to. A calorie count is a poor instrument for a definition. Japan has already decided institutionally; Japanese speakers are still arguing linguistically; the IOC has stopped arguing and simply stopped.

Where you live, does the label change anything real? Does calling it a sport unlock school funding, tax treatment, visa categories, or just an argument at dinner?

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