TRAINING FOR FAT LOSSImpacts o f Resis tance, Interva l , and Endurance Train ing

James Krieger, M.S.

Three Ways In Which Exercise Can Impact Fat Loss

• Increase energy expenditure

– During training

• Exercise energy expenditure is one of the strongest predictors of changes in fat mass1

– During recovery

• Resting metabolic rate (RMR)

• Excess post-exercise oxygen consumption (EPOC)

• Repartitioning effect

– Maintain Fat-Free Mass (FFM) while losing fat

– Impact on abdominal fat

• Impact on appetite

1. Barwell et al., Metabolism, 58:1320-1328, 2009

Impacts of Exercise on Energy

Expenditure

Impact of Endurance Exercise On Energy Expenditure During Exercise

• Direct relationship between volume & energy expenditure for given intensity

• Direct relationship between intensity & energy expenditure for given volume

Impact of Endurance Exercise On Post-Exercise Energy Expenditure1

• Exponential relationship between exercise intensity & EPOC magnitude

• For intensities 50%+ VO2 max, linear increase in EPOC as exercise duration increases

• EPOC only comprises 6-15% of net exercise energy expenditure

– e.g., 15 – 38 kcal for a 250 kcal session

1. LaForgia et al., J Sports Sci, 24:1247-1264, 2006

Impact of Resistance Training On Energy Expenditure1

• Reported session energy expenditures in literature range from to 60 to 360 kcal in most studies

• Reported EPOCs range from 6 to 52 kcal over 1-2 hours post-exercise in most studies

• Total energy cost in 24 h (session + EPOC) will range from ~60 – 400 kcal

1. Meirelles & Gomes, Rev Bras Med Esporte, 10:131-138, 2004

Impact of Resistance Training Volume on Energy Expenditure

• Energy expenditure of single set training (1x15 RM, 8 exercises) is low1-2

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1. Phillips & Ziuraitis, J Strength Cond Res, 17:350-355, 2003

2. Phillips & Ziuraitis. J Strength Cond Res, 18:606-609, 2004

Impact of Resistance Training Volume on Energy Expenditure

• High volume (3 sets of 10 exercises) produced greater energy expenditure during session than 1 set but not significantly higher RMR1

1. Heden et al., Eur J Appl Physiol, 111:477-484, 2011

Predicting Energy Expenditure from a Resistance Training Session1

• 0.874 * Height(cm) – 0.596 * Age(years) – 1.016 * Fat Mass (kg) + 1.638 * Lean Mass (kg) + 2.461 * Total Volume Load (sets*reps*load lifted in kg) * 0.001 – 110.742

– R2 = 0.77, SEE = 28.5 kcal

– Example:

• 178 cm male, 45 years, 66 kg lean mass, 11 kg fat mass, 13600 kg load volume (312 repetitions)

– Estimated energy expenditure = 148 kcal

• The Krieger Quick & Dirty Method

– 0.5 kcal per rep for smaller muscle groups, 1 kcal per rep for larger muscle groups

– R2 = Probably Pretty Low But It’s a Quick and Dirty Method so Who Cares

– 312 reps of smaller muscle group upper body training = 156 kcal

1. Lyttle et al., Med Sci Sports Exerc, February 13, 2019 [Epub

ahead of print]

Impact of Resistance Training on Post-Exercise Energy Expenditure• Whole body resistance training (8x6 of 8 exercises) that emphasized

eccentric action (1 s con, 3 s ecc) increased RMR by ~150 kcal/d for up to 72 h in both trained and untrained subjects1

1. Hackney et al., J Strength Cond Res, 22:1602-1609, 2008

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Impact of Resistance Training on Post-Exercise Energy Expenditure• 100-min of whole body resistance training (5 sets of 10 exercises,

10-15 reps per set) increased RMR by 60 kcal/d at 24 h in women1

• In a similar study on men, RMR was elevated 4.7-9.4% (85 – 169 kcal for an 1800 kcal/d RMR)2

1. Osterberg & Melby, Int J Sport Nutr Exerc Metab, 10:71-81, 2000

2. Melby et al., J Appl Physiol, 75:1847-1853, 1993

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RMR: Resistance vs Steady State Training

• RMR elevated at 24 h after both resistance and endurance training, then returned to baseline1

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1. Jamurtas et al. Eur J Appl Physiol, 92:393-398, 2004

Impact of Resistance Training on 24- Energy Expenditure

• Whole body resistance training (4 sets of 10 exercises) increased 24-h EE by 327 kcal/d1

– 76% of increase (229 kcal) came during and within 30 min after exercise

1. Melanson et al., Med Sci Sports Exerc, 34:1793-1800, 2002

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Impact of Resistance Training on 24- Energy Expenditure

• Whole body resistance training (3x15 of 10 exercises) increased 24-h EE by 263 kcal/d1

– 40% of increase (105 kcal) attributed to energy cost of training itself

1. Van Etten et al., J Appl Physiol, 82:298-304, 1997

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24 Hr EE: Resistance vs Steady State Training

• Similar elevations in 24-hr EE between resistance training (70-min circuit, 4x10 of 10 exercises at 70% 1-RM) and endurance training (49 min at 70% VO2 max)1

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1. Melanson et al. Med Sci Sports Exerc, 34:1793-1800, 2002

Does Exercise Prevent Slowdown of Metabolism With

Weight Loss?

Impact of Resistance Training on RMR During Weight Loss

• Some studies show resistance training maintains or reduces loss of RMR during weight loss1-3

– Confounder: RMR measured too close to last training session

• Most do not3-9

1. Broeder, et al. Am J Clin Nutr, 55:802-810, 1992

2. Bryner et al., J Am Coll Nutr, 18:115-121, 19993. Stiegler & Cunliffe, Sports Med, 36:239-262, 20064. Wadden et al., J Consult Clin Psychol, 65:269-277, 19975. Geliebter et al., Am J Clin Nutr, 66:557-563, 19976. Johannsen et al, J Clin Endocrinol Metab, 97:2489-2496, 20127. Ballor et al., Metabolism, 45:179-183, 19968. Hunter et al., Med Sci Sports Exerc, 47:1950-1957, 20159. St-Onge et al., Menopause, 20:194-201, 2013

Impact of Endurance Training on RMR During Weight Loss

• Some studies show endurance training maintains or reduces loss of RMR during weight loss1-4

– Confounder: RMR measured to close to last training session

• Most do not4-10

1. Broeder, et al. Am J Clin Nutr, 55:802-810, 1992

2. Wadden et al., J Consult Clin Psychol, 65:269-277, 19973. Thompson et al., Int J Sport Nutr, 6:41-61, 19964. Stiegler & Cunliffe, Sports Med, 36:239-262, 20065. Geliebter et al., Am J Clin Nutr, 66:557-563, 19976. Ballor & Poehlman, Eur J Appl Physiol, 71:535-542, 19957. Johannsen et al, J Clin Endocrinol Metab, 97:2489-2496, 20128. Ballor et al., Metabolism, 45:179-183, 19969. Hunter et al., Med Sci Sports Exerc, 47:1950-1957, 201510. van Dale et al., Eur J Clin Nutr, 43:441-451, 1989

“High intensity interval training burns more fat and creates a greater afterburn than steady state training does…”

Supramaximal Interval Running Produces Only Slightly Greater EE & EPOC Than Work-Matched Submaximal

Continuous Running

• 20x1 min intervals @ 105% VO2 max vs 30 min continuous @ 70% VO2 max1

– EE difference of 57 kcal over 9 h

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1. Laforgia, et al. J Appl Physiol, 82:661-666, 1997

Intervals Do Not Produce Superior Energy Expenditure Over 3 Hours (Session+EPOC)1

• HIE (4x4 min @ 95% peak HR, with 3 min active recovery

• SIE (6x30 sec Wingate sprints, with 4 min active recovery

• SSE (30 min @ 80% peak HR)

• EPOC short-lived, lasting only 1 hour after exercise

1. Tucker et al., J Strength Cond Res, 2016

Interval Training vs. Steady Cardio For Fat Loss

Keating et al., Obes Rev., May 17, 2017 [Epub ahead of print]

• No significant difference between types of exercise for fat loss, whether energy expenditure/workload per session were matched or interval training involved less time & energy expenditure

– When interval training involved less time commitment & energy expenditure, results tended to favor continuous training (P = 0.09)

Interval Training vs. Steady Cardio For Fat Loss

Keating et al., Obes Rev., May 17, 2017 [Epub ahead of print]

• No significant difference between types of exercise for body fat percentage

“High intensity interval training burns more fat and creates a greater afterburn than steady state training does…”

Does Added Muscle Boost Your Energy

Expenditure?

What Determines Your Resting Metabolic Rate (RMR)?

• Fat-Free Mass (FFM)– Internal organs

• 24.4 kcal/lb

– Muscle• 6 kcal/lb

– Bone• 1 kcal/lb

• Fat– 2 kcal/lb

Three Ways In Which Exercise Can Impact Fat Loss

• Increase energy expenditure

– During training

• Exercise energy expenditure is one of the strongest predictors of changes in fat mass1

– During recovery

• Resting metabolic rate (RMR)

• Excess post-exercise oxygen consumption (EPOC)

• Repartitioning effect

– Maintain FFM while losing fat

– Impact on abdominal fat

• Impact on appetite 1. Barwell et al., Metabolism, 58:1320-1328, 2009

Impacts of Exercise on FFM Retention

Impact of Resistance Training on FFM During Weight Loss

• Most studies show resistance training maintains or reduces loss of FFM during weight loss1-12

• Some do not12-13

1. Broeder, et al. Am J Clin Nutr, 55:802-810, 1992

2. Geliebter et al., J Diabetes Obes, 1:1-7, 20143. Geliebter et al., Am J Clin Nutr, 66:557-563, 19974. Bryner et al., J Am Coll Nutr, 18:115-121, 19995. Johannsen et al, J Clin Endocrinol Metab, 97:2489-2496, 20126. Frimel et al, Med Sci Sports Exerc, 40:1213-1219, 20087. Kraemer et al., Med Sci Sports Exerc, 31:1320-1329, 19998. Hunter et al., Obesity, 16:1045-1051, 20089. St-Onge et al., Menopause, 20:194-201, 201310. Longland et al., Am J Clin Nutr, 103:738-746, 201611. Joseph et al., Diabetes Care, 24:1863-1869, 200112. Stiegler & Cunliffe, Sports Med, 36:239-262, 200613. Wadden et al., J Consult Clin Psychol, 65:269-277, 1997

Impact of Endurance Training on FFM During Weight Loss

• Some studies show endurance training maintains or reduces loss of FFM during weight loss1-7

• Others do not7-11

1. Broeder, et al. Am J Clin Nutr, 55:802-810, 1992

2. Geliebter et al., J Diabetes Obes, 1:1-7, 20143. Ballor & Poehlman, Int J Obes, 18:35-40, 19944. Johannsen et al, J Clin Endocrinol Metab, 97:2489-2496, 20125. Frimel et al, Med Sci Sports Exerc, 40:1213-1219, 20086. Kraemer et al., Med Sci Sports Exerc, 31:1320-1329, 19997. Stiegler & Cunliffe, Sports Med, 36:239-262, 20068. Wadden et al., J Consult Clin Psychol, 65:269-277, 19979. Geliebter et al., J Diabetes Obes, 1:1-7, 201410. Hunter et al., Obesity, 16:1045-1051, 200811. van Dale et al., Eur J Clin Nutr, 43:441-451, 1989

FFM & Muscle Aren’t the Same!

• 14 obese females on 800 kcal/d1

– 16 kg weight loss• 24% FFM, 76% FM

• Significant increase in cross-sectional area of FT & ST muscle fibers

• FFM can decrease due to fluid losses even if body protein remains intact2

1. Donnelly, et al. Am J Clin Nutr, 58:561-565, 1993

2. Van Loan et al, Eur J Clin Nutr, 48:408-415, 1994

How Does Resistance Training Help Preserve Muscle During Weight Loss?

• Energy deficits reduce muscle protein synthesis 19-27%1-3

• Resistance training brings muscle protein synthesis back to normal during energy restriction2-3

1. Pasiakos et al. J Nutr, 140:745-751, 2010

2. Areta et al, Am J Physiol Endocrinol Metab, 306:E989-997, 20143. Murphy et al., Am J Physiol Endocrinol Metab, 308:E734-743, 2015

EB = Energy Balance

ED = Energy Deficit

PL = Placebo After Weight Training

15 g = 15 g Whey After Weight Training

30 g = 30 g Whey After Weight Training

Does High Intensity Exercise or Interval

Training Help Reduce Abdominal Fat?

Does High Intensity Exercise Or Interval Training Help Reduce Abdominal Fat?

• Out of 7 studies1-7, only one showed greater abdominal fat loss with high intensity interval training compared to moderate intensities6

– Self-reported energy intake was non-significantly lower in interval group6

1. Cho et al., Int J Sports Med, 32:468-475, 2011

2. Coker et al., Metab Syndr Relat Disord, 7:363-368, 20093. Bacchi et al., Hepatology, 58:1287-1295, 20134. Gutin et al., Am J Clin Nutr, 75:818-826, 2002

5. Shepherd et al., PLoS One, 10:e0139056, 20156. Trapp et al., Int J Obes, 32:684-691, 2008

7. Tremblay et al., Metabolism, 43:814-818, 1994

Three Ways In Which Exercise Can Impact Fat Loss

• Increase energy expenditure

– During training

• Exercise energy expenditure is one of the strongest predictors of changes in fat mass1

– During recovery

• Resting metabolic rate (RMR)

• Excess post-exercise oxygen consumption (EPOC)

• Repartitioning effect

– Maintain FFM while losing fat

– Impact on abdominal fat

• Impact on appetite 1. Barwell et al., Metabolism, 58:1320-1328, 2009

Impact of Exercise on Appetite

Impact of Exercise On Appetite

• Exercise has only a trivial effect on absolute energy intake (effect size = 0.14)1

1. Schubert et al. Appetite, 63:92-104, 2013

Impact of Exercise On Appetite

• Exercise has a large effect on relative energy intake (creating an energy deficit, effect size = -1.23)1

1. Schubert et al. Appetite, 63:92-104, 2013

Three Ways In Which Exercise Can Impact Fat Loss

• Increase energy expenditure

– During training

• Exercise energy expenditure is one of the strongest predictors of changes in fat mass1

– During recovery

• Resting metabolic rate (RMR)

• Excess post-exercise oxygen consumption (EPOC)

• Repartitioning effect

– Maintain FFM while losing fat

– Impact on abdominal fat

• Impact on appetite 1. Barwell et al., Metabolism, 58:1320-1328, 2009

Exercise Is Critical For Long-Term Weight Maintenance

Pavlou et al., Am. J. Clin. Nutr., 49:1115-1123, 1989

• In a meta-analysis, diet+exercise resulted in 5 lb more sustained weight loss (20%) over 1 year than diet alone1

1. Curioni & Lourenco, Int J Obes, 1168-1174, 2005

2,500 calories/week

1,000 calories/week

Tate et al., 2007

2,500 Calories Per Week Of Physical Activity For Long-Term Weight Maintenance

• Individuals in the National Weight Control Registry (NWCR) expend 2,620 kcal/wk in physical activity1

1. Phelan et al., Obesity, 14:710-716, 2006

SummaryEffects of Exercise On Energy Expenditure

• Endurance Training

– Direct relationship between volume/intensity and energy expenditure

– Impact on EPOC/RMR is minimal

• Most benefit is from energy expended in session itself

• Likely does not prevent reduction in RMR with weight loss

– Higher volumes results in better long-term fat loss outcomes

SummaryEffects of Exercise On Energy Expenditure

• Resistance Training

– Direct relationship between volume and energy expenditure

• Typical energy expenditures of low volume (8-10 total sets) are around 70-135 kcal

• Energy expenditure of high volume sessions (30-50 sets) can range from 200-400 kcal

– Significant increases in EPOC/RMR by 60-170 kcal/d over 24-72 h post-exercise

• Likely due to increased protein turnover

• RMR elevation is temporal to training session

– Likely does not prevent reduction in RMR with weight loss

– ~50-75% of energy expenditure benefit is from energy cost of session itself + early EPOC

– Added muscle does not significantly elevate RMR

SummaryEffects of Exercise On Energy Expenditure

• Interval Training

– No magical fat loss benefit

• Interval training and steady cardio are similarly efficacious for fat loss

• Interval training is not more “time efficient”– Data suggests moderate intensity exercise is

slightly superior if less time & energy is expended through interval training

• Personal preference & goals should dictate choice– Post-exercise elevation in energy expenditure is

only marginally higher than steady-state cardio and likely will not aid fat loss

• Elevation is temporary, lasting 1-3 hours after exercise

SummaryEffects of Exercise On Tissue Repartitioning

and Appetite• Both endurance and resistance training have

been shown to preserve FFM or reduce loss of FFM during weight loss

– Resistance training is likely superior

• Restores suppressed muscle protein synthesis during energy restriction

– FFM and muscle are not the same

• Loss of FFM does not mean loss of muscle

• No impact of exercise intensity on abdominal fat

• On average, exercise has only a trivial effect on energy intake

– Relative energy intake is significantly decreased due to energy cost of exercise itself

SummaryOther Notes

• Cardio can be optional– Fat loss can be achieved

with resistance training & dietary restriction alone, but diet will likely need to be more well controlled unless training volume is high

– Cardio in addition to weight training can allow for greater food intakes due to elevated energy expenditure

SummaryOther Notes

• Individualized programming is critical– Any exercise program for fat loss needs to take into

consideration personal preferences, individual schedules, injury status, biomechanical limitations, etc.

– Potential for overtraining needs to be considered when combining high-intensity protocols (like weight training and interval training)

• High levels of physical activity are critical for long-term weight maintenance

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