Influence of water-based exercise on energy intake, appetite, and appetite-related hormones in adults: A systematic review and meta-analysis

Probably not a substantial claim: may not pass S3 (load-bearing).

Exercise-induced anorexia does not necessarily lead to compensation, i.e., eating more at the next meal.

“The phenomenon has been described as exercise-induced anorexia but does not necessarily lead to compensation i.e., eating more at the next meal (Schubert et al., 2013).”

• cites Schubert et al., 2013 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Overall summary risk of bias judgement for each outcome was derived by the highest RoB level in any of the assessed domains.

“Following guidance given for RoB 2.0 (Higgins et al., 2011), we derived an overall summary risk of bias judgement (low; some concerns; high) for each specific outcome, whereby the overall RoB for each study was determined by the highest RoB level in any of the domains that were assessed.”

• cites Higgins et al., 2011 sourcePartly supported

  The Summary assessment of risk of bias section calls for an overall judgment for each outcome within each trial, and Table 3 (reproduced in the Discussion; page unavailable) assigns high risk when one or more key domains are high risk. But it does not say to use the highest level across any assessed domain: it emphasizes key domains and contextual judgment. The paper uses low, unclear, and high risk, not the citing sentence’s RoB 2.0 category “some concerns.” (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

The temperature of swimming pool water is typically between 20 and 25°C.

“As the temperature of swimming pool water is typically between 20 and 25 • C, and seasonal open water swimming can involve temperatures as low as 10 • C-15 • C (Tipton & Bradford, 2014), exercising in cold water could stimulate hunger encouraging energy intake after exercise.”

• cites Tipton & Bradford, 2014 sourceCould not verify

  The Relevant regulations section describes 25°C as a threshold for body cooling during exercise and 10–15°C as a range many agencies define as cold water. Neither passage says that swimming pool water is typically 20–25°C; a search for pool-temperature guidance found no such statement in our copy. (LLM, conf=0.72)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The data for the land-ISO-cycle session in Metz et al. (2021) was omitted from the meta-analysis and only the land-cycle versus aqua-cycle data was used.

“The data for the land-ISO-cycle session was therefore omitted from the meta-analysis and only the land-cycle versus aqua-cycle data was used).”

• cites Metz, Isacco, Fearnbach, et al. (2021) sourceSupported

Classified as probably not a substantial claim.

When immersed in water, body heat is lost through both conduction and convection.

“When immersed in water, body heat is lost through both conduction and convection (Fudge, 2016).”

• cites Fudge, 2016 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Exercise increases energy expenditure and can contribute to overall weight loss, if no compensation in energy intake occurs.

“Exercise increases energy expenditure and can contribute to overall weight loss, if no compensation in energy intake occurs (Hall et al., 2011).”

• cites Hall et al., 2011 sourceSupported

May combine two claims.

King et al. (2011) reported that AG was suppressed during swimming compared to control, but the effect was short-lived with concentrations returning to control values 1 h after exercise.

“The authors reported that AG was suppressed during swimming compared to control, but the effect was short-lived with concentrations returning to control values 1 h after exercise.”

• cites King et al. (2011) sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

When body temperature rises in response to exercise, POMC neurons express signals via TRPV1, which results in suppression of appetite.

“Jeong et al. (2018) reports that when body temperature rises in response to exercise, the POMC neurons express signals via transient receptor potential vanilloid 1 (TRPV1) which results in the suppression of appetite.”

• cites Jeong et al., 2018 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Risk of bias within each included study was assessed using RoB 2.

“Risk of bias within each study (RoB 2) Sterne et al. (2019).”

• cites Sterne et al. (2019) sourceSupported

May combine two claims.

Total PYY includes both PYY 1-36 and PYY 3-36, which have divergent actions on appetite.

“total PYY which includes both PYY 1-36 and PYY 3-36 , reported by Manning and Batterham (2014) to have divergent actions on appetite.”

• cites Manning and Batterham (2014) sourceSupported

Probably not a substantial claim: may not pass S4 (based).

This is the first systematic review and meta-analysis to address the research question of whether water-based exercise influences energy intake, appetite, and appetite-related hormones differently to land-based exercise in adults.

“This is the first systematic review and meta-analysis to address the research question, does water-based exercise influence energy intake, appetite, and appetite related hormones differently to land based exercise in adults?”

May combine two claims.

The search identified only one chronic training study (Fico et al., 2021), which was carried out over a 12-week period.

“The search identified only one chronic training study (Fico et al., 2021), which was carried out over a 12-week period.”

• cites Fico et al., 2021Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Eight acute studies were undertaken over a single day for each experimental trial (duration 5-8 h), with trial arms separated by 4-7 days.

“Eight acute studies were undertaken over a single day for each experimental trial (duration 5-8 h), with trial arms separated by 4-7 days.”

Probably not a substantial claim: may not pass S3 (load-bearing).

There is clear disparity between published works in the temperatures used to classify the temperature of water which could influence interpretation.

“There is clear disparity between published works in the temperatures used to classify the temperature of water which could influence interpretation.”

Classified as probably not a substantial claim.

It was only possible to perform a meta-analysis on the extracted energy intake data.

“It was only possible to perform a meta-analysis on the extracted energy intake data.”

Classified as probably not a substantial claim.

There is a paucity of data examining the hypothesis that exercising in cold water could stimulate hunger.

“There is a paucity of data examining this hypothesis.”

May combine two claims.

The studies included in the present meta-analysis all reported water temperature being comfortably warm (27-34°C) and above the temperature that may cause shivering.

“The studies included in the present meta-analysis all reported water temperature being comfortably warm (27-34 • C) and above the temperature that may cause shivering.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The database search yielded 615 articles.

“The database search yielded 615 articles.”

Classified as probably not a substantial claim.

After removing duplicates and screening, a total of 9 studies were sourced for analysis and review.

“A total of 9 studies were sourced for analysis and review.”

May combine two claims.

Six studies included water-based exercise versus a non-exercise control, six included water- versus land-based exercise, and two included water-based exercise only performed at different water temperatures.

“Six studies included water-based exercise versus a non-exercise (landbased) control, six included water-versus land-based exercise, and two included water-based exercise only performed at different water temperatures.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Data for hunger and appetite-related hormones is discussed narratively.

“Therefore, data for hunger and appetite-related hormones is discussed narratively.”

May combine two claims.

Both cycling and swimming reduced body mass over time from 87.3 (5.2) to 85.9 (5.0) kg and 88.9 (4.9) to 86.4 (4.5) kg respectively.

“Furthermore, both cycling and swimming reduced body mass over time 87.3 (5.2) to 85.9 (5.0) kg and 88.9 (4.9) to 86.4 (4.5) kg respectively.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

All eight acute studies included a single bout of exercise (≤60 min) which was fully supervised.

“All eight studies included a single bout of exercise (≤60 min) which was fully supervised.”

May combine two claims.

In Gwinup (1987), over 6 months, fifteen females living with obesity gradually incorporated 1 h per day of swimming, cycling, or walking into their daily routine, but only the cyclists and walkers reduced their body mass by the end of the trial (12% versus 10% reduction respectively).

“Over a period of 6 months, fifteen females living with obesity gradually incorporated 1 h per day of swimming, cycling, or walking into their daily routine, but only the cyclists and walkers reduced their body mass by the end of the trial (12% versus 10% reduction respectively).”

• cites Gwinup (1987) sourceNot checked — no full text of the source

May combine two claims.

Both swimming and cycling facilitate body mass loss.

“The authors didn't monitor energy intake but similar to Lopera et al. (2016) reported an average reduction of ~2 kg in body mass after both swimming and cycling interventions, suggesting both modes of exercise facilitate body mass loss.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

When body temperature falls in response to cold exposure, ArRP neurons are activated, which results in hunger-dependent feeding behaviour in mice.

“When body temperature falls in response to cold exposure, Yang et al. (2021) shows in mice that ArRP neurons are activated, which results in hunger-dependent feeding behaviour.”

• cites Yang et al., 2021 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The reporting and conduct of this systematic review and meta-analysis are based on the PRISMA statement.

“The reporting and conduct of this systematic review and metaanalysis are based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement (Page et al., 2021).”

• cites Page et al., 2021Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Data selection and extraction was conducted independently by the principal investigator and then checked independently by other members of the review team.

“Data selection and extraction was conducted independently by the principal investigator (MG) and then checked independently by other members of the review team.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The study by Thackray et al. (2020) applied different methods of measuring energy expenditure which could have affected the outcome.

“The study by Thackray et al. (2020) applied different methods of measuring energy expenditure which could have affected the outcome.”

• cites Thackray et al. (2020) sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

It was not possible to carry out sensitivity analysis as only two studies compared different water temperatures.

“It was not possible to carry out sensitivity analysis as only two studies compared different water temperatures.”

May combine two claims.

Hunger is suppressed during and immediately after water-based exercise, but participants were hungrier in the subsequent hours when compared to control or a land-based comparator based on the available empirical literature.

“Finally, whilst a meta-analysis was not possible due to a paucity of data, it is posited that hunger is suppressed during and immediately after water-based exercise, but participants were hungrier in the subsequent hours when compared to control or a land-based comparator based on the available empirical literature.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Title and abstract screening was completed independently by MG, and three reviewers checked all title and abstract screening.

“Title and abstract screening was completed independently by MG.Three reviewers (DB, DT and JA) then checked all title and abstract screening.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Habitual cold-water swimmers may develop a greater storage of body fat than individuals primarily engaging in land-based forms of exercise.

“Habitual cold-water swimmers may develop a greater storage of body fat than individuals primarily engaging in land-based forms of exercise (Flynn et al., 1990).”

• cites Flynn et al., 1990 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Risk of bias was assessed using the revised Cochrane Risk of bias tool for randomised trials (RoB 2.0).

“Risk of bias was assessed using the revised Cochrane Risk of bias's tool for randomised trials (RoB 2.0).”

May combine two claims.

Sensitivity analysis did not alter heterogeneity or statistical significance for water- versus land-based exercise.

“Sensitivity analysis did not alter heterogeneity or statistical significance.”

Probably not a substantial claim: may not pass S3 (load-bearing).

This review is registered with PROSPERO (ID number CRD42022314349).

“This review is registered with the Prospective Register of Systematic Reviews (PROSPERO) database (ID number CRD42022314349).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Discrepancies in risk of bias judgements or justifications were resolved by discussion to reach consensus between the two review authors.

“Any discrepancies in judgements of risk of bias or justifications for judgements were resolved by discussion to reach consensus between the two review authors, with a third review author ready to act as an arbiter but this was not necessary.”

May combine two claims.

Of the eligible studies, 55.6% were considered low risk and 44.4% presented with some concerns on risk of bias.

“Of the eligible studies, 55.6% were considered low risk and 44.4% presented with some concerns.”

May combine two claims.

White et al. (2005) reported that participants aqua cycling at 60% of VO2max for 45 min in cold (20°C) versus neutral water (33°C) led to a 44% increase in energy intake when presented with an ad-libitum meal, equivalent to 1125 kJ.

“White et al. (2005) reported participants aqua cycling at 60% of VO 2 max for 45 min in cold (defined as 20 • C) versus neutral water (defined as 33 • C), led to a 44% increase in energy intake when presented with an ad-libitum meal, equivalent to 1125 kJ.”

• cites White et al. (2005) sourceNot checked — no full text of the source

May combine two claims.

The study by Fico et al. (2020) was a 12-week study which didn't monitor energy intake, and appetite-related hormones were measured in their total form which is less sensitive to appetite.

“The study by Fico et al. (2020) was a 12-week study which didn't monitor energy intake, and appetite-related hormones were measured in their total form which is less sensitive to appetite.”

• cites Fico et al. (2020)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Two review authors independently applied RoB 2.0 to each included study and recorded supporting information and justifications for judgements of risk of bias for each domain.

“Two review authors (MG and DB) independently applied the tool to each included study and recorded supporting information and justifications for judgements of risk of bias for each domain (low; some concerns; high).”

Probably not a substantial claim: may not pass S3 (load-bearing).

All full texts were individually screened by three reviewers to assess suitability for inclusion in the systematic review.

“All full texts were individually screened by three reviewers (DB, DT and MG) to assess suitability for inclusion in the systematic review.”

May combine two claims.

Sensitivity analysis removing Thackray et al. (2020) did not alter heterogeneity (I2 = 56%), and therefore the data is included.

“Sensitivity analysis showed that removing the one study with slight concerns relating to the measurement of energy expenditure (Thackray et al., 2020), did not alter heterogeneity (I 2 = 56%), and therefore the data is included.”

• cites Thackray et al., 2020 sourceNot checked — no full text of the source

May combine two claims.

Although this meta-analysis suggests that cold water exercise may cause a person to eat more, the 95% confidence intervals for the individual studies are very large so results should be interpreted with caution.

“Although this meta-analysis suggests that cold water exercise may cause a person to eat more, the 95% confidence intervals for the individual studies are very large so results should be interpreted with caution.”

May combine two claims.

Energy intake was higher by ~330 kJ after exercising in water versus control, supporting the notion that exercise promotes food intake, at least in the short term.

“Following meta-analysis of six studies (King et al., 2011;Metz et al., 2021aMetz et al., , 2021bMetz et al., , 2021c;;Thackray et al., 2020, & White et al., 2005), the present review demonstrated that energy intake was higher by ~330 kJ after exercising in water versus control, supporting the notion that exercise promotes food intake, at least in the short term.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

It is likely that the duration of exercise and intensity were not sufficient for participants to remain thermoneutral which therefore caused compensatory feeding.

“It is likely that the duration of exercise and intensity were not sufficient for participants to remain thermoneutral which therefore caused compensatory feeding.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the short term, appetite is better controlled when people are more physically active and trained.

“This is supported by previous research that highlights in the short-term appetite is better controlled when people are more physically active and trained (Rocha et al., 2013).”

• cites Rocha et al., 2013 sourceNot checked — no full text of the source

May combine two claims.

In Halse et al. (2011), more calories were consumed after both cold-water immersion and neutral-water immersion compared to control, equivalent to an extra 803-1075 kJ.

“Although there was little difference in energy intake between cold versus neutral water immersion, more calories were consumed after both cold-water immersion (4893 ± 1554 kJ) and neutral-water immersion (5167 ± 1975 kJ) when compared to control (4089 ± 1585 kJ), equivalent to an extra 803-1075 kJ.”

• cites Halse et al. (2011) sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The review may have missed relevant data from studies that were not published in English.

“Finally, we may have missed relevant data from studies that were not published in English.”

Classified as probably not a substantial claim.

Simply being submerged in water may result in increased energy intake.

“as Halse et al. (2011) suggest simply being submerged in water may result in increased energy intake.”

• cites Halse et al. (2011) sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Normal functioning of the appetite-regulating hormones ghrelin, GLP-1, and PYY is altered in people with obesity due to increased adiposity.

“the normal functioning of the appetite regulating hormones; ghrelin, glucagon-like peptide (GLP-1), and peptide YY (PYY), are altered in people with obesity due to increased adiposity (Zouhal et al., 2019).”

• cites Zouhal et al., 2019 sourceNot checked — no full text of the source

May combine two claims.

There were only a small number of studies and, due to a paucity of data and variability among studies, a meta-analysis could not be undertaken for appetite or appetite-related hormones.

“Firstly, there were only a small number of studies and due to a paucity of data and variability among studies a meta-analysis could not be undertaken for appetite or appetite related hormones.”