How much does dieting impact your performance?

Tacklewasher wrote: »

Commented elsewhere on this, but I'm wondering how much a deficit impacts performance? Thinking about running personally.

Been doing a 5K parkrun most Saturdays. On my 50th run I kinda went all out and did what was, for me, a decent time. 28:24. Not a PB, but close. Was dieting and losing ~1.25 lbs per week at that point. Then I had a couple of weeks where I was eating pretty much maintenance and, then ran about the same perceived effort (both runs I kinda stood by the garbage can at the end, in case) and turned in a time of 27:33. PB by far. Back to dieting targeting ~1 lb loss and not running as hard getting 28:30 - 29:00.

Is this pretty typical?

Yes. Or at least that’s my experience as well. I will see performance degradation in everything from easy run paces/efforts, recovery times, overall fatigue, strength, etc when I’m in a deficit vs when I’m not. How much of a drop really depends on how long, what volume, what I’m doing, etc. But the kind of time difference you mention for a park run would be well within a normal realm for deficit vs not for me. When your body is essentially eating itself (as it is when you’re in a deficit), you just aren’t in the best state for optimal performance.

My coach has me eat at maintenance for anywhere from a few days to a few weeks (depending on race length and goals) prior to a race, and when training volume is too high for me to carry a deficit and also recover (like the peak month of marathon training).

I don't know about running, but I can tell a difference in my hiking stamina when I eat less than maintenance or lower carb. More resting, less pushing myself.

cmriverside wrote: »

I don't know about running, but I can tell a difference in my hiking stamina when I eat less than maintenance or lower carb. More resting, less pushing myself.

Ditto. If I don't fuel well the day before a long hike I can really feel the difference in my stamina.

"How much does dieting impact your performance?"

Not a lot, often I see and measure no difference at all. But.....
During my main period of weight loss:

• I didn't do an everyday deficit so my maintenance days kept my energy levels up and my big and/or intense training days would normally be fully fuelled. (5:2 eating pattern)
• My rate of weight loss was only 1lb/week.

At maintenance when I need or want to cut some weight ahead of a big event such as a Century ride:

• I still don't have an everyday deficit. My most intense sessions would be fully fuelled, the long low intensity days don't need to be fully fuelled and I can tolerate a deficit those days without impact or excessive hunger.
• Still cut at about 1lb/week.
• Can sustain a high training volume of cycling while in that small deficit and make good performance improvements but after about 6 or 7 weeks I start to notice poorer recovery and training performance. (So I start my cut and event prep about 8 weeks out so I can taper diet up and exercise down before the event to be fresh and fully fuelled.)

It's hard to unpick all the various factors to come up with a "typical" response. Length of time dieting, size of deficit, duration of exercise, style of eating etc..

CSARdiver wrote: »

This is very common and what I suspect leads to so many diet fails. Trying to implement a caloric deficit and increase exercise is a losing game. It's only a matter of time before this plan fails.

I either go into deficit and maintain or reduce performance, or I train for performance and eat at maintenance or surplus. To do otherwise is setting yourself up for failure.

Maybe you need to add "excessive" before deficit and swap the general "yourself" with the personal "myself" as that's far too broad a generalisation.

I only saw performance increases, no failure at all.
Got fitter, faster, vastly improved endurance and also stronger while I got lighter.
Training for events in a deficit is very common across many disciplines such as martial arts with weight classes and events where lighter weight confers a performance edge (cycling etc.).

The more usual problem is the too much too soon approach, too much deficit and a far too rapid increase in exercise and exercise intensity. (The Biggest Loser approach you could call it.)

Really need to define performance as it relates to you? What goes into your training? How much of a deficit are you eating at? Other stressors in life? Depending on the variables, it may or may not affect your performance. For myself and people I know that train like me either experience poor recovery, loss in performance, digress in strength, or some combination. It's hard to give a clear-cut answer here, the answer is more specific to you. If you're not experiencing any right now, then what you're doing is fine. Just pay attention to your performance targets and energy levels.

sijomial wrote: »

CSARdiver wrote: »

This is very common and what I suspect leads to so many diet fails. Trying to implement a caloric deficit and increase exercise is a losing game. It's only a matter of time before this plan fails.

I either go into deficit and maintain or reduce performance, or I train for performance and eat at maintenance or surplus. To do otherwise is setting yourself up for failure.

Maybe you need to add "excessive" before deficit and swap the general "yourself" with the personal "myself" as that's far too broad a generalisation.

I only saw performance increases, no failure at all.
Got fitter, faster, vastly improved endurance and also stronger while I got lighter.
Training for events in a deficit is very common across many disciplines such as martial arts with weight classes and events where lighter weight confers a performance edge (cycling etc.).

The more usual problem is the too much too soon approach, too much deficit and a far too rapid increase in exercise and exercise intensity. (The Biggest Loser approach you could call it.)

/agree - this is what I had in mind when responding.

An experienced individual has already gone through much of this process and knows how diet impacts performance and able to push boundaries. A beginner has not had this experience, which often leads to failure after attempting the too much too soon.

sijomial wrote: »

AnnPT77 wrote: »

sijomial wrote: »

CSARdiver wrote: »

This is very common and what I suspect leads to so many diet fails. Trying to implement a caloric deficit and increase exercise is a losing game. It's only a matter of time before this plan fails.

I either go into deficit and maintain or reduce performance, or I train for performance and eat at maintenance or surplus. To do otherwise is setting yourself up for failure.

Maybe you need to add "excessive" before deficit and swap the general "yourself" with the personal "myself" as that's far too broad a generalisation.

I only saw performance increases, no failure at all.
Got fitter, faster, vastly improved endurance and also stronger while I got lighter.
Training for events in a deficit is very common across many disciplines such as martial arts with weight classes and events where lighter weight confers a performance edge (cycling etc.).

The more usual problem is the too much too soon approach, too much deficit and a far too rapid increase in exercise and exercise intensity. (The Biggest Loser approach you could call it.)

Yes, but there are reasons for training that aren't related to the intensity/speed that training achieves in the moment, and some of those sports are structured to allow for some refueling before the actual competition. (I'm not disagreeing with you, just saying there may be a little more nuance. Lightweight rowers and coxswains each have weigh-ins pretty close to comp times. They can use different strategies between weigh-in and race, and I'd bet most do. And I'm not speaking for cycling, because I don't have relevant knowledge/experience. My experience is with sports where lower weight is a qualification issue, not so much per se a performance enhancer).

Purely speculatively, reading the forums here suggests to me that marginal performance under different fueling conditions may be one of those things where there's some individual variation: Some folks slightly more sensitive/responsive to fueling than others.

As one common example, some people report excellent results from fasted cardio, and some (like me) report under-performance. If it's so, the reasons could be as much psychological as much as muscle/CV related (in the sense that mood is fueling-related, not in the sense that psychological = imaginary). Some people also appear to get more of a TDEE boost (from subconscious NEAT, presumably) from going to maintenance than others, too.

Just thinking out loud. Well, in electrons.

I was really talking about a many weeks training camp such as done by fighters. Although there is refuelling period between the weigh in and the bout and they step into the ring heavier than their weigh in - over the course of weeks they are often losing substantial amounts of weight while simultaneously training to peak fitness.

One cycling example would be Bradley Wiggins in his TdF winning year - he cut down to an extreme low level of weight and body fat (from an already very lean level) to improve his power to weight ratio which is a crucial cycling performance metric. Setting himself up for success not failure.

A deficit does not automatically equal poor performance was my counter point to a very pessimistic post. If you followed the absolutism in the statement then no walker would successfully progress through the C25K program or newbie to the gym take up a beginner strength program and make a success of it purely because they were in an undefined calorie deficit.

Agree about the difference in response which is why I wouldn't have responded if the post was "myself" rather than the general "yourself".

It's unclear to me whether they're at peak performance during the cut, and I can't speak for your sport at all.

They're certainly making fitness/training progress during the cut, but IME some sports' training plans aim for peak performance at the time of comp, sometimes with sacrificed short-term performance for good training effect en route. In collegiate rowing, this idea of when to peak seems to be sort of part of the strategy, and you can perhaps see symptoms of it in competitive performance. (Peak for conference championships in order to make NCAAs, if in a tough conference; maybe choose to macro peak later, if a strong squad in a weaker conference . . . to put it very simplistically.) I know other sports also used periodized plans, but I'm not as familiar with their nature.

To be even more cartoon-ish in making a point, and shifting subject: Taper exists for a reason. An athlete has been getting great training effect by working very hard, but isn't at peak performance potential before the taper. Is the cut/refeed similar, for some sports? I don't know.

I agree that a cut isn't necessarily a cause of underperformance, but I'm guessing it matters more in some scenarios than others (as well as the individual variation). Might even be a training effect for coping with stressors like the cut - getting better at handling it, with repetition?

But . . .

Tacklewasher's OP was comparing his race performance while losing weight at a pretty good (but not crazy) clip, with his performance while eating maintenance calories.

(In that context, maybe we're both off in the weeds a bit . . . . :drinker: ).

(edited: "Calories" not "categories", near the end . . . not auto-correct, stupid touch-typing muscle/brain disconnect!)

jjpptt2 wrote: »

I don't have anything quantitative, but I definitely notice restricted cals moreso with cardio than I do strength training... I seem to run out of gas faster. Fasted cardio + calorie deficit = about 45 minutes of solid effort. A little less if other conditions are poor (sleep, macros, recovery, etc).

Pretty subjective, yes... but I have LOADS of subjectiveness that supports that subjection.

It's amazing how different we all are. I had too large a deficit for about a week, and didn't feel much on the bike, but I wasn't able to lift weight I had lifted recently.

AnnPT77 wrote: »

sijomial wrote: »

AnnPT77 wrote: »

sijomial wrote: »

CSARdiver wrote: »

This is very common and what I suspect leads to so many diet fails. Trying to implement a caloric deficit and increase exercise is a losing game. It's only a matter of time before this plan fails.

I either go into deficit and maintain or reduce performance, or I train for performance and eat at maintenance or surplus. To do otherwise is setting yourself up for failure.

Maybe you need to add "excessive" before deficit and swap the general "yourself" with the personal "myself" as that's far too broad a generalisation.

I only saw performance increases, no failure at all.
Got fitter, faster, vastly improved endurance and also stronger while I got lighter.
Training for events in a deficit is very common across many disciplines such as martial arts with weight classes and events where lighter weight confers a performance edge (cycling etc.).

The more usual problem is the too much too soon approach, too much deficit and a far too rapid increase in exercise and exercise intensity. (The Biggest Loser approach you could call it.)

Yes, but there are reasons for training that aren't related to the intensity/speed that training achieves in the moment, and some of those sports are structured to allow for some refueling before the actual competition. (I'm not disagreeing with you, just saying there may be a little more nuance. Lightweight rowers and coxswains each have weigh-ins pretty close to comp times. They can use different strategies between weigh-in and race, and I'd bet most do. And I'm not speaking for cycling, because I don't have relevant knowledge/experience. My experience is with sports where lower weight is a qualification issue, not so much per se a performance enhancer).

Purely speculatively, reading the forums here suggests to me that marginal performance under different fueling conditions may be one of those things where there's some individual variation: Some folks slightly more sensitive/responsive to fueling than others.

As one common example, some people report excellent results from fasted cardio, and some (like me) report under-performance. If it's so, the reasons could be as much psychological as much as muscle/CV related (in the sense that mood is fueling-related, not in the sense that psychological = imaginary). Some people also appear to get more of a TDEE boost (from subconscious NEAT, presumably) from going to maintenance than others, too.

Just thinking out loud. Well, in electrons.

I was really talking about a many weeks training camp such as done by fighters. Although there is refuelling period between the weigh in and the bout and they step into the ring heavier than their weigh in - over the course of weeks they are often losing substantial amounts of weight while simultaneously training to peak fitness.

One cycling example would be Bradley Wiggins in his TdF winning year - he cut down to an extreme low level of weight and body fat (from an already very lean level) to improve his power to weight ratio which is a crucial cycling performance metric. Setting himself up for success not failure.

A deficit does not automatically equal poor performance was my counter point to a very pessimistic post. If you followed the absolutism in the statement then no walker would successfully progress through the C25K program or newbie to the gym take up a beginner strength program and make a success of it purely because they were in an undefined calorie deficit.

Agree about the difference in response which is why I wouldn't have responded if the post was "myself" rather than the general "yourself".

It's unclear to me whether they're at peak performance during the cut, and I can't speak for your sport at all.

They're certainly making fitness/training progress during the cut, but IME some sports' training plans aim for peak performance at the time of comp, sometimes with sacrificed short-term performance for good training effect en route. In collegiate rowing, this idea of when to peak seems to be sort of part of the strategy, and you can perhaps see symptoms of it in competitive performance. (Peak for conference championships in order to make NCAAs, if in a tough conference; maybe choose to macro peak later, if a strong squad in a weaker conference . . . to put it very simplistically.) I know other sports also used periodized plans, but I'm not as familiar with their nature.

To be even more cartoon-ish in making a point, and shifting subject: Taper exists for a reason. An athlete has been getting great training effect by working very hard, but isn't at peak performance potential before the taper. Is the cut/refeed similar, for some sports? I don't know.

I agree that a cut isn't necessarily a cause of underperformance, but I'm guessing it matters more in some scenarios than others (as well as the individual variation). Might even be a training effect for coping with stressors like the cut - getting better at handling it, with repetition?

But . . .

Tacklewasher's OP was comparing his race performance while losing weight at a pretty good (but not crazy) clip, with his performance while eating maintenance calories.

(In that context, maybe we're both off in the weeds a bit . . . . :drinker: ).

(edited: "Calories" not "categories", near the end . . . not auto-correct, stupid touch-typing muscle/brain disconnect!)

Peak performance during a cut?
Depends on the training plan - is it purely linear progression or periodised intensity?
Depends on the start point.
Too many depends.....

Taper also has many aspects unrelated to calories (funny enough I often lose weight when I taper due to losing stress and soreness related water weight). Different sports/events are going to have very different needs and how much a refeed matters is very different, for my 5hr plus events being fully fuelled should have a significant impact, for a short event not so much when muscles being rested and fresh is by far the dominant factor for me.

I'm also sure some people simply get a feelgood and energised feeling from being well fuelled out of proportion to the physiological needs of the event itself (less than 400cals for a 5k perhaps?), that feelgood factor might be OP's reason for setting a PB.
Sometimes your performance just takes a step up and you can't positively identify the cause or causes - does make sense to repeat what works as an individual though.