Weight loss and training

RicerDalemon

New member
Background: I have been running for ca. 2 years, about 3200 lifetime miles. I am 5'8" and weigh between 147 and 150 (so, BMI 23 or just under). My volume for the last year has been in the 40-45 mpw range. Since November I've been training for my first marathon, in May. In the course of this training I've recently bumped my mileage up to the low 50s, as much as I've ever run before (I'm aiming to peak in a few months at 65-70 miles). I'm shooting for a time around 3:30. So far training has gone so well I've allowed myself to hope I might even pull off a faster time.
So my question: I think I'm a bit of a heavy runner and that I could be faster if I dropped twenty pounds. I also appreciate that I'm just starting out and that many heavier runners are a lot faster than me. In other words, I recognize that my weight is not necessarily the only or even the most important factor limiting my performance.
Still, if losing weight is a path to being a better and a faster runner I'd like to do that. So my questions:
Surely I risk sacrificing some adaptations/supercompensations if I start restricting calories during my training program. Is there any way to predict what sacrifices those might be precisely? Am I going to lose aerobic fitness, is my lactate threshold going to come down, am I going to lose muscle strength, is it going to take me longer to recover between long runs/speed sessions?
Given these potential disadvantages and my current BMI, could the potential gains from getting lighter compensate or even put me ahead?
I had the crazy idea I might alternate weeks of caloric restriction (to lose weight) with weeks of maintenance (to allow for training adaptations). Does that even make sense or would I be better off restricting my calories at half the margin overall?
I have some experience with dieting while running at medium volume and it wasn't a great feeling. On the other hand, I'm never not running these days, so if I need to get thinner to be a better runner, there will have to be some pain.
Thanks for any help, and again apologies if this doesn't belong here.
 
I'm no running expert but it would seem to depend in large part on where your current bodyfat percentage is at. If it's high you'll be able to slowly lose weight without losing significant muscle mass and without feeling too crappy. If you're already mostly muscle it's a whole different story.
 
Most marathon runners have both low bodyfat % and low muscle mass, as you drop the fat your recovery may take a little longer due to the energy restriction and you will loose muscle mass and strength unless specifically including training to maintain muscle strength. Loosing muscle is most likely to affect your ability to kick into a higher speed for short bursts, otherwise carrying a lot of muscle size is not beneficial for marathon.
 
Surely I risk sacrificing some adaptations/supercompensations if I start restricting calories during my training program. Is there any way to predict what sacrifices those might be precisely? Am I going to lose aerobic fitness, is my lactate threshold going to come down

I'm not up to marathon distances yet, but I'm closing in on a half while running 20-25 miles/week in preparation for an ironman in October. I started running at a weight of about 280 lb and now weigh under 220 during which time my VO2 max has gone up damatically (26.0 to 43.4), as has my lactate threshold in relation to VO2max (from being at 78% of VO2 max to being at 91% of VO2 max):
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So it is certainly possible to lose fat without negatively affecting training adaptations, but I believe it takes a lot more work/focused effort to do so correctly. Specifically, my goal would be to lose fat and not lean mass (what I attribute to my success so far). To do so, I recommend:

1) consuming between 1g of protein per pound of lean mass and 1g of protein per pound of total body weight.
2) keeping your daily calorie deficit under 20 per pound of body fat to prevent muscle loss. If you're at 15% body fat at 150lbs, that would mean you have 22.5 lb of fat so 22.5 x 20 means your deficit could be as high as 450 calories a day. This would mean you would be losing under 1 lb per week (3500 calories per pound).
2a) On days you run a lot, you'll need more calories than on days you don't run to stay within your target calorie deficit. I recommend getting those extra calories primarily from carbs (this is sometimes called carb cycling)
3) add strength training 2 days a week, either before your runs or on off days. Focus on lower repetitions (5-12 reps) which, if doing body weight exercises, may mean lifting very very slowly as you get stronger
4) Drink plenty of water (the amount varies depending on exercise & temperature, but I try to make sure my urine has only a little color)
5) Get plenty of rest - both sleep and rest/active recovery days
6) consider doing 2 shorter morning and evening runs rather than 1 really long run to give your body more recovery.

am I going to lose muscle strength, is it going to take me longer to recover between long runs/speed sessions?
Everything is a compromise. If you lose weight too rapidly it will come from muscle. If you lose weight more slowly, you can probably maintain the strength you have. If you don't lose weight you may gain muscle strength...

The same goes for recovery - you'll need a little more recovery losing weight slowly and a lot more recovery losing weight rapidly compared to maintaining.

Given these potential disadvantages and my current BMI, could the potential gains from getting lighter compensate or even put me ahead?
I had the crazy idea I might alternate weeks of caloric restriction (to lose weight) with weeks of maintenance (to allow for training adaptations). Does that even make sense or would I be better off restricting my calories at half the margin overall?
I'm very confident you'll be faster & healthier by losing weight slowly. My approach is to do so steadily, but I suspect alternating a faster weight loss week with a maintenance week would end up with you losing about the same weight and maintaining about the same strength. Good luck,
 
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You may see cardio and weights as two distinct types of clean training, but when you put them together, you have a powerful combination for fat loss success. Do high-intensity cardio for shorter times, or try high-intensity interval training. High-intensity exercise, even if it is short, can speed up your metabolism and mobilize this fat in the post-workout period. This requirement may be met by a group exercise program such as an exercise bike cycle. However, don't overdo it, because burning fat is a long-term project and you don't want to burn out.
 
You may see cardio and weights as two distinct types of spam link removed but when you put them together, you have a powerful combination for fat loss success. Do high-intensity cardio for shorter times, or try high-intensity interval training. High-intensity exercise, even if it is short, can speed up your metabolism and mobilize this fat in the post-workout period. This requirement may be met by a group exercise program such as an exercise bike cycle. However, don't overdo it, because burning fat is a long-term project and you don't want to burn out!
 
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Thank you a lot
 
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