I’ll preface this by saying this is anecdotal and speculative.
We were talking about diet and exercise at a dinner with friends the other night and one of the points of discussion was an emphasis on diet in terms of weight loss. A point that came up that attempting to lose weight isn’t recommended at the same time as training for endurance athletic events. (Long distance swimming, tri’s, marathon/ultra, etc) The thinking is that attempting to lose weight during the training cycle will likely reduce performance both in training and at the event while being difficult to have any success at due to increased appetite and decreased willpower. This fits in with some noodling I have been doing on multiple equilibrium points for weight loss.
Multiple equilibria refers to a situation where a system has more than one point where it can rest. I’m bastardizing that concept, perhaps poorly, in this case to indicate multiple points of optimization of an outcome. In this case, multiple different ways for weight loss to occur at a ‘better rate’ though all might not be equal. This isn’t intended to be a complete list. The reason I think the notion is important is that multiple equilibria might explain part of the contending (and confusing) possibilities for weight loss.
Anecdotally, I can think of several situations where weight loss seems to have been more optimized in my case. Long duration\moderate load\high frequency\high calorie – this is a case experienced in thru hiking. Thru hiking is a long distance hiking excursion lasting weeks or months. Daily hiking occurs in the 6-10 hour range. Load factors are pace, backpack weight, and altitude gain/loss. Caloric intake is high. In this circumstance, there almost isn’t a caloric intake reconcilable with holding weight. Sufficient caloric intake often becomes a problem. Depending on the load factors (it is possible to go slow enough, take enough days off, lower hours hiked etc) to maintain or increase weight. Many people lose weight in this combination of factors. Light to medium duration\light load\high frequency\low caloric intake – this case is experienced where diet was a focus and exercise was limited to walks lasting about an hour 5+ days/week under a light load. Load factors were normal pace, one hill, work back pack. The key here was that the level of activity was light enough to maintain a lower calorie diet without failure. Frequency of activity was high.
Contra example: Mixed duration\mixed load\high frequency\lower calorie – this is the case in marathon and ultramarathon training while trying to get lighter. Duration tend to be an hour plus with long day duration 3 – 6 hours. Load factors are types of training (track workouts, tempo), pace, elevation gain. Frequency is typically 4-6 days a week. Caloric intake is a balancing act between sufficient energy for workout performance and muscle maintenance while trying to create caloric deficit sufficient for weight loss. This did not lead to weight loss. The line to balance is too fine. Individual workouts produce different caloric deficits that a generalized daily caloric load doesn’t match. Mental fatigue and mismatch lead to failures.
So where is this going? My current thinking is that weight loss for an endurance athlete is probably best achieved outside a training cycle where diet is the leading focus with exercise dependent on maintaining the diet. Once a set level is achieved, then moving onto a training cycle with a goal of weight maintenance. For the non athlete, I suspect that the best outcome is dietary focused with frequent light to medium duration and load exercise again dependent on diet maintenance.
In both cases it would imply getting comfortable with a dietary pattern that can be maintained and leads to weight loss and only then bringing exercise levels up to but backing away from any level that challenges dietary maintenance (staying on the diet) or causes failures. There is some non zero level of exercise that should always be reconcilable with a maintainable diet (walking slowly on a flat surface) but the emphasis would be on care in dialing back should conflicts arise.
This is all purely speculative of course.