What's so bad about low weights/high reps?

you are seeing differences because you are losing fat covering the muscle, not because of anything you are doing with weights. sorry but you're not building muscle with small weights especially if it's the same amount you've been lifting since time began and especially if you are able to lift more. and you're also not building muscle unless your eating over your maintenance. and doing tons of reps are more for endurance and not strength. strength and endurance are different things .. it's like saying you can get better at math by just doing a zillion arithmetic problems and not moving on to something harder. doing all those extra arithmetic problems when you've already mastered the subject isnt making you better at math.

one of the main reasons to lift weights when you are losing weight is that it ensures that your body hangs on to as much of your lean body mass as possible while you eat at a deficit.

muscle is active and requires lots of calories to maintain. if you're not giving your body the calories it needs to maintain itself (which you dont when you're trying to lose weight) AND not properly using your muscles (by progressively overloading the muscle) then your body will start eating away at your muscle which i'm going to assume you dont want to happen

There is nothing "wrong" with doing low weights/high reps. It is a proven way to achieve your fitness goals. There is science to back this up (see links below). Both light/high reps or heavy/low reps are good. Both work. Personally, I find that low weights/high reps are difficult and I prefer to do higher weights/low reps, but that's just me. Everyone is different. Do what feels best for you and your fitness goals.

http://www.webmd.com/fitness-exercise/news/20120427/high-reps-with-low-weights-builds-muscle-too

http://www.telegraph.co.uk/health/healthnews/9229304/Light-weights-better-than-heavy-for-building-muscle.html

http://www.tsbmag.com/2012/05/02/study-reveals-high-repslow-weight-effective-in-building-muscle/

Low weights with high reps is for toning that muscle area. Building larger muscles would need gradual increase in weights. Good luck.

There is nothing "wrong" with doing low weights/high reps. It is a proven way to achieve your fitness goals. There is science to back this up (see links below). Both light/high reps or heavy/low reps are good. Both work. Personally, I find that low weights/high reps are difficult and I prefer to do higher weights/low reps, but that's just me. Everyone is different. Do what feels best for you and your fitness goals.

http://www.webmd.com/fitness-exercise/news/20120427/high-reps-with-low-weights-builds-muscle-too

http://www.telegraph.co.uk/health/healthnews/9229304/Light-weights-better-than-heavy-for-building-muscle.html

http://www.tsbmag.com/2012/05/02/study-reveals-high-repslow-weight-effective-in-building-muscle/

This is describing the study I was talking about. I think the problem is that typically people don't do light weights to fatigue, and as I mentioned, this study says lighter, a feather isn't gonna do anything. And progression is an important element people often miss... Ill see the same girl using the same 5 lb weight for a year... If it was a challenge at first, it shouldn't still be after a year!

Using the 5# dumbbells did SOMETHING for me, but not compared to what real strength training did.
For me, the BEST part of lifting heavy is that it's quick. About a half hour, three times a week.

What Lorina said! the lighter weights are not useless and you can get some benefit from them as the studies listed above indicate. But it takes soooo long with sooo many reps and then there is not all the neuromuscular and hormonal benefits of heavier/ lower rep strength training.

The best thing is the time efficiency. I do a very intensive routine with a 10 minute cardio warm up, compound lifts (Starting Strength) and supplementals for the stabilizing muscles. I am in and out in 60 minutes 3 times a week. My routine is intense enough that I am exausted at the end and could not do it more than 3x per week. I have a life and as much as I enjoy my workouts, I enjoy that they don't dominate my time!

My humble opinion... these things go in cycles... a few years ago it was the low weights, high reps, now it is the high weights, low reps... Someone else will come up with another book, another study, etc... in a year or 2 telling all these people who are lifting heavy they are wrong. I do whatever I feel like... I change it up all the time...

your humble opinion is nice, but it's not fact. amongst people who know what they are talking about there has been no debate on things... The big difference has been the internet and it's ability to weed out garbage from fact. More people are learning about the benefits of weight training. It's not going away. Learn a bit about the body and you'll learn why.

http://www.bodyrecomposition.com/training/weight-training-for-fat-loss-part-1.html

I'm considering getting the book New Rules of Lifting for women, because so many people on here have recommended it. But in discussions of it, and in the sample of the book I read, I noticed the general consensus seems to be that women need to lift heavy to see real results, and that low weights/high reps routines were basically just gimmicks.

This really surprised me, because all my weight training is done at home with small dumbbells -- I've never gone higher than 5lbs. -- and I still see a noticeable difference in my arms and thighs. There is definition where there wasn't any before, and I feel stronger and more fit. The workouts were also not easy by any means just because the weights were small -- there were lots of reps done in complex sequences that made it HARD to get through my strength circuits.

So what gives? Do both methods work, or is one really better than the other? Why is using low weights getting bashed all of a sudden when it clearly works for people if they put in the effort?

It is good to change it up all the time. Nothing wrong with what you are doing, but it is only endurance. You should do a variety of Strength, Hypertrophy, and Endurance if you really want to work on your build. No matter how hard you lift you don't have to worry about getting big. Girls don't have the hormones to get big. The body builders you see in pictures mostly take extra hormones or steroids to get big. I lift heavy and I'm super tiny. I look more ripped because I am lean (under 12%) body fat. If I allowed my body to gain more fat then I would have a softer look, but I'm so short that I feel better leaner. And if I allowed my body to get even more fat then you wouldn't really see the muscle and I would look "thick" (like I did most of my life until last year LOL).

If I could encourage all girls to lift heavy I would. Not just heavy but a good women's routine that constantly mixes it up. Heavy some blocks of time, moderate, light, combinations. Not only is it good for your body to mix it up but it keeps you from getting bored. I recently had my DXA scan done and at 51.5 years of age I have the bone density of a super athletic 30 year old. That is a direct result of lifting for over 30 years. Now if that is not scientific proof that lifting weights keeps you younger I don't know what is! Also I believe it's why people think I look younger than I really am.

See for yourself:

http://www.myfitnesspal.com/topics/show/752246-i-m-afraid-to-try-an-new-weight-lifting-program-now

http://www.myfitnesspal.com/topics/show/745151-i-got-a-compliment-from-rusty-moore-from-fitness-black-book

http://www.myfitnesspal.com/topics/show/740340-i-lost-60-lbs-at-age-51-anyone-can-any-workout

http://www.myfitnesspal.com/topics/show/752246-i-m-afraid-to-try-an-new-weight-lifting-program-now

http://www.myfitnesspal.com/topics/show/742284-lets-see-some-muscle-chicks-real-ones

http://www.myfitnesspal.com/topics/show/746754-how-to-get-abs-with-pics

http://www.myfitnesspal.com/topics/show/734011-desserts-always-make-me-wake-up-ripped-with-pics

http://www.myfitnesspal.com/topics/show/734137-the-new-me-pictures-not-posing

I do that but also low rep / high weight, med / med, combos, you just don't want to do the same thing all the time. And what ever you do, no matter the reps, you want to NEED the rest before the next set or you are not pushing hard enough.

The routine I do consists of weight lifting first and cardio second, but I still do cardio (mainly running). I change up everything all the time. My running is sometimes long easy runs, sometimes HIIT, sometimes shorter medium pace runs. My weight routine changes each day, each week, Circuits, Intermittent Super Sets, Fibonacci Pyramids, X-sets, Progress Venus Pyramids, and some splits, constantly changing it up, everything a variety of Strength, Hypertrophy, and Endurance.

Legs; In addition to Dealdlift's, Stiff Leg Dead Lifts, Sumo Dead Lifts and Squats I do Bulgarian Split Squats, Lunges, Reverse lunges, Curtsey lunges, Step Ups, Crossover Bench Step Ups, One legged Deadlifts (T-Bend), Lunge Matrix, Bowler Squat, One Legged Get Ups, Bower Squat and calf Raise, Bowler Squat + Stiff Leg Deadlift, Curtsey Lunge + Dumbbell Squat, T-Bend + Y-Squat, Reverse Lunge & Step Up, Curtsey Lunge + Step Up, Y-squat, Narrow Stance Squat

For upper body I do Standing Shoulder Press, Standing Dumbell Curls, Lying Tricep extension, Pullovers, Bent Barbell Row, Standing lateral Raise, Standing front Raise, Curl and Press, Shoulder Press + Curl, Dips, Lying Tricep Extensions + Flyes, Venus Raise (a type of snatch), Bent Row + Standing Lateral Raise, Pullovers, Pushup + Dips, Standing Dumbbell curls + Overhead Tricep Extension, Bent Lateral Raise + Pullovers, One Arm Dumbbell row, Flyes + Pushups, Seated Curl & Tate Press, Seated Curls + Overhead Tricep Extension, Pushups, Pullovers + Dips, Bent Barbell Row, Lateral Raise + Full Front Raise, Venus Raise + Dips, Standing Dumbbell curls + Lying Tricep Extension, Upright Row + Dips, Bent Barbell Row, Flat bench Press, Incline Bench Press, Bent Row Narrow, Bent Row + Kickback,

Then some upper and lower combos; Squat and Front Raise, Step Up & Press, Step Up + Standing Shoulder Press, Squat & Press, Squat & Swing, Curtsy Lunge + Standing Shoulder Pres, T-Bend & Row, Pike Front Rais + Curtsey Lunge, Flat Bench Press + Step Up.

Core: Bar Bell Rollouts (you can start out with Stability Ball Roll Outs), Swiss Ball Pikes (you can start out with Stability Ball Curl Ups), and planks. As you advance Swiss Ball Pike and pushup.

I probably forgot some but you get the idea.

I always was taught that I would need a spotter to use large barbells and I don't know anyone at my gym to ask to spot me and I can't afford a trainer. I don't know where to begin.

Learn the lifts and you don't need a spotter. You really only need a spotter when you you're attempting a weight or reps that you're unsure of. You can always ask somebody else lifting nearby for a spot. Most people don't mind.

This really surprised me, because all my weight training is done at home with small dumbbells -- I've never gone higher than 5lbs. -- and I still see a noticeable difference in my arms and thighs. There is definition where there wasn't any before, and I feel stronger and more fit.

Wait till you see how fast you'll get noticeable results with 15 and 20 lb dumbbells! 3x the benefits, in 1/3 of the time!!! Would you rather spend 15 mins doing 4 sets or 20 reps with something that weighs less than your purse or would you rather lift something a little bit heavier and be finished after 3 sets of 8 reps? I don't know about you, but I don't want to workout one second longer than I have to.

I'm a runner, and no expert on weights, but it seems to me that what you're doing now is effectively really inefficient cardio. No exercise is "useless"; it all gets you moving and is better than nothing, but it seems like you'd get more results out of either real cardio like HITT, running, or swimming, or lifting heavier. A combination of cardio and lifting is probably your best overall bet for weight loss and general fitness.

So in honesty, light weights at high reps might be enough to at least not lose much muscle in a calorie deficit

Actually, not for that either. It's been proven that maximal strength training is also better for this while on a calorie deficit. There's little reason to focus on high reps for compound movements and really most movements in-general. There are some strength training applications for high reps but they're usually only used with isolation exercises of small muscle groups and generally more in bodybuilding than anything.

I agree with what you said. I never said light weights would be superior, I said it could be sufficient to not lose much muscle. Note the excessive use of qualifiers because I don't know of any study that has really shown that statement to be untrue. In fact, this brand new study showed that with only aerobic training, participants had no statistically significant change in lean mass, while losing fat mass. These were sedentary, untrained individuals, but still... I've looked and can't find a lick of proof that you can't maintain muscle using high rep. Please send me a citation for this if you have one, as I'd be super interested to read it.

J Appl Physiol. 2012 Sep 27. [Epub ahead of print]
Effects of Aerobic and/or Resistance Training on Body Mass and Fat Mass in Overweight or Obese Adults.
Willis LH, Slentz CA, Bateman LA, Shields AT, Piner LW, Bales CW, Houmard JA, Kraus WE.
Source
1Duke University Medical Center.
Abstract
Recent guidelines on exercise for weight loss and weight maintenance include resistance training as part of the exercise prescription. Yet, few studies have compared the effects of similar amounts of aerobic and resistance training on body mass and fat mass in overweight adults. STRRIDE AT/RT, a randomized trial, compared aerobic training, resistance training and a combination of the two to determine the optimal mode of exercise for obesity reduction. Participants were 119 sedentary, overweight or obese adults who were randomized to one of three 8-month exercise protocols: 1) RT: resistance training; 2) AT: aerobic training; and 3) AT/RT: aerobic and resistance training (combination of AT and RT). Primary outcomes included total body mass, fat mass and lean body mass. The AT and AT/RT groups reduced total body mass and fat mass more than RT (p<0.05), but they were not different from each other. RT and AT/RT increased lean body mass more than AT (p<0.05). While requiring double the time commitment, a program of combined AT and RT did not result in significantly more fat mass or body mass reductions over AT alone. Balancing time commitments against health benefits, it appears that AT is the optimal mode of exercise for reducing fat mass and body mass while a program including RT is needed for increasing lean mass in middle-aged, overweight/obese individuals.

I'm doing New Rules and I love it. Never thought I would. I'm only 4 weeks in and can see noticeable results. And Im getting stronger each week. Try it!