DOES CARDIO BURN MUSCLE OFF? WRONG! CARDIO CAN HELP BUILD MORE MUSCLE!!!

 

---

CARDIO FOR MUSCLE BUILDING SUMMARY

 

• Cardio for muscle building may have potential benefits.
• Increased blood flow is associated with increases in muscle protein synthesis
• Low capillarization in muscle is associated with poor nutrient delivery, reduced satellite cell activation, and less muscle growth.
• Both high-intensity and low-intensity exercise stimulate increased capillaries, with the volume of exercise being the biggest driver.
• Combining aerobic exercise spaced out with resistance exercise may result in greater muscle growth thru increased capillarization with a greater source of blood flow to the muscle.

 

CARDIO FOR MUSCLE BUILDING? IS CARDIO AND RESISTANCE EXERCISE BETTER THAN RESISTANCE EXERCISE ALONE

Satellite cells are essential for muscle growth and repair. Studies have shown that aging results in blunted activation of satellite cells, which can be related to age-related muscle loss.

Resistance training activates satellite cells. Satellite cells normally stay dormant; however, satellite cells proliferate (i.e., split) after resistance exercise and fuse into muscle tissue, resulting in muscle growth.

Previous studies have shown that people with greater satellite cell activation have greater increases in muscle growth. Hyper-responders rapidly increase muscle growth after resistance exercise and have greater satellite cell activation than those who make lesser gains in muscle growth.

Some suggest that cardio is counter-productive to muscle growth, but the newest research is shaking up the bodybuilding world. Thomas et al. recently reported that aerobic exercise combined with resistance exercise resulted in greater muscle growth than resistance exercise alone.

CARDIO FOR MUSCLE BUILDING THEORY

The theory is that aerobic exercise can increase satellite cell activation by increasing capillary blood flow to the muscle.

Increased capillary blood flow to muscle from aerobic exercise has enhanced satellite cell activation by increasing the concentration of growth factors and hormones for muscle growth. It makes sense that more blood flow and nutrients will allow for a greater anabolic response.

The study had 14 men and women perform either resistance exercise or a combination of resistance and aerobic exercise for 10 weeks.

The results were that the combination of aerobic and resistance exercise resulted in hypertrophy in type I and type II; however, resistance training alone experienced hypertrophy in only type II fibers. Satellite cell content was greater in the aerobic training + resistance training group compared to resistance training alone.

Before the study, the subjects with the greatest capillary-to-fiber perimeter exchange ratio (a measure of blood perfusion to the muscle) experienced the greatest muscle hypertrophy following the training intervention.(25)

This study shows that cardio is good for cardiovascular health and may enhance muscle growth in response to resistance exercise by enhancing blood flow and nutrients to satellite cells.

DOES CARDIO BUILD MUSCLE?

Who doesn’t like a great pump in the gym? A good pump feels great but can also lead to greater muscle growth. A previous study found that cell swelling post-exercise was correlated with muscle growth (1).

If you maximize muscle pumps while increasing muscle growth, ensure the weight is sufficiently heavy to stimulate muscle growth.

This was demonstrated in a 2018 study in which subjects trained with different intensities to complete muscular failure with a similar total workload for twelve weeks. Subjects trained with 20%, 40%, 60%, and 80% of their 1-repetition maximum. Training at 40, 60, or 80% of one-repetition maximum 1RM led to similar muscle growth, whereas the 20% of 1RM groups had less biceps and quad growth.

This suggests that lightweight (<20% of a 1RM) will produce suboptimal growth, and weights above 85% won’t further increase muscle growth (2).   Thus, using a weight that you can use for more than 30-40 reps will be less conducive to muscle growth than reps in the 15-30 rep ranges.

BUILDING MUSCLE WITH CARDIO: INCREASING BLOOD SUPPLY TO MUSCLE FOR MORE MUSCLE GROWTH

Cardio for muscle building has been a myth for years in circles. Now, a new term called muscle-building cardio suggests cardio may enhance muscle growth beyond just doing resistance exercise.

SHOULD I DO CARDIO IF TRYING TO BUILD MUSCLE?

Muscles need a rich supply of blood flow to deliver nutrients, oxygen, etc. Capillaries supply the muscle with blood flow. Some studies have found that an increase in a capillary network of muscle leads to greater muscle growth.

CARDIO FOR MUSCLE BUILDING

Untrained subjects can have a 10–30 % increase in capillarization after 6–8 weeks of exercise training. In contrast, elite aerobic athletes with years of progressive exercise training express a capillary-to-muscle fiber ratio of more than 200 % of that of untrained individuals.(3)

Supplements that can increase muscle blood flow are nitrates (i.e., beet juice), cocoa, curcumin, green tea extract, and other polyphenols.(4-7) Studies suggest that increased blood flow has a positive effect on increasing muscle protein synthesis. (8) The nitric oxide-enhancing drug Viagra has also been shown to increase muscle protein synthesis after just one week. (9)

IS CARDIO BAD FOR MUSCLE GROWTH?

Aerobic exercise is well known to increase blood capillary supply, but resistance exercise can also increase muscle capillaries to muscle. Researchers had subjects perform a 12-week resistance exercise program.

During the first week of the training period, the workload was increased gradually from 70% (10–15 repetitions) of 1-repetition maximum (1RM) to 80% of 1RM (8–10 repetitions). After that, training was performed at 80% 1RM. Workload intensity was adjusted based on the outcome of the successive 1RM tests (performed at weeks 4 and 8).

After just 2 weeks of training, there was an increase in the capillary-to-fiber ratio in the muscle, which was matched by an increase in muscle growth.(10)

Another interesting observation is that older men have reduced capillary-to-fiber ratios and smaller increases in muscle growth compared to younger men. (11, 12)

One study found that men with the lowest capillary blood supply in muscle had the lowest increases in muscle growth, suggesting adequate blood flow to the muscle is essential for muscle growth.(13)

Another study found that those with greater muscle capillarization resulted in greater muscle satellite cell activation and accelerated recovery.(14) Others have found that those with the highest capillary-to-fiber ratio had higher muscle mass than those with the lowest capillary-to-fiber ratio.(15)

DOES CARDIO MAKE YOU LOSE MUSCLE?

A combination of aerobic and resistance exercise has favorable effects on muscle capillarization. Researchers investigated the impact of aerobic interval training in younger and older highly resistance-trained men.

Participants were bodybuilders, retired bodybuilders, or men who were resistance-trained for recreational purposes in their offseason.

Participants underwent a 10-week endurance cycling training program comprising five 6-min intervals at 75% max heart rate (HRmax) separated by 4-min intervals at 90% HRmax. All participants performed at least 2 upper body and 2 lower-body resistance training sessions per week.

At the end of the study, adding inter resulted in increased capillarization in both the younger and older men without loss of muscle size. The younger men had greater increases in capillarization than the older men.

Other studies have found that aerobic exercise and resistance exercise combined resulted in greater muscle growth than resistance exercise alone after 5 weeks of cardio and resistance exercise (bouts separated by 6 hours) versus resistance exercise training in isolation (14 vs. 8 %)(21).

Following the combination of aerobic and resistance exercise, a more robust increase appeared due to a greater increase in type I fibers. Similarly, Mikkola et al. reported almost double the quadriceps growth (11 vs. 6 %) following a combination of aerobic and resistance exercise (*60 min of variable-intensity cycling and progressive resistance, separated by 24 h) compared with resistance exercise alone after 21 weeks of training.(22)

HOW TO DO CARDIO WITHOUT LOSING MUSCLE

A common question among lifters is, “does cardio after weights affect muscle growth?” A complete article on the subject can be found here.

When aerobic and resistance exercises are performed in low volumes and with adequate rest between activities, aerobic and resistance exercise may augment muscle growth compared to resistance exercise alone.

Maximal muscle growth responses can occur with aerobic and resistance exercise by :

(a) separating exercise bouts by 6–24 hours,

(b) adopting strategies that minimize overall exercise aerobic volume (i.e., using high-intensity intervals, 2–3 days of aerobic exercise, and <2 days of leg lifting), and (c) favoring cycling as opposed to running.(23)

IS HIGH-REP EXERCISE THE BEST CARDIO FOR MUSCLE GROWTH?

There is no difference when lifting with higher or lower reps and its effect on capillarization. For example, researchers had subjects train with low and high reps.

The high-repetition/low-load intervention consisted of three sets of 20–25 repetitions/set, so the load varied between 30 and 50% of the participant’s 1RM.

The low-repetition/high-load intervention consisted of three sets of 8–12 repetitions/set, corresponding to 75–90% of 1RM. All the sets were taken to complete muscular failure. At the end of the study, both high-repetition/low-load and low-repetition/high-load resistance training increased muscle capillarization.

Both groups equally increased VEGF and nitric oxide similarly. The high repetition, lightweight group, demonstrated the biggest increase in the capillary to fiber in type II fibers, yet this did not result in greater muscle growth.(24)

CARDIO FOR MUSCLE BUILDING KEY POINTS

•  Increased blood flow is associated with increases in muscle protein synthesis
• Low capillarization in muscle is associated with poor nutrient delivery, reduced satellite cell activation, and less muscle growth.
• Both high-intensity and low-intensity exercise stimulate increased capillaries, with the volume of exercise being the biggest driver.
• Combining aerobic exercise spaced out with resistance exercise may result in greater muscle growth thru increased capillarization with a greater source of blood flow to the muscle.

---

REFERENCES

1.         Hirono T, Ikezoe T, Taniguchi M, Tanaka H, Saeki J, Yagi M, et al. Relationship Between Muscle Swelling and Hypertrophy Induced by Resistance Training. J Strength Cond Res. 2022;36(2):359-64.

2.         Lasevicius T, Ugrinowitsch C, Schoenfeld BJ, Roschel H, Tavares LD, De Souza EO, et al. Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy. Eur J Sport Sci. 2018;18(6):772-80.

3.         Ingjer F. Capillary supply and mitochondrial content of different skeletal muscle fiber types in untrained and endurance-trained men. A histochemical and ultrastructural study. Eur J Appl Physiol Occup Physiol. 1979;40(3):197-209.

4.         Phillips BE, Atherton PJ, Varadhan K, Limb MC, Williams JP, Smith K. Acute cocoa flavanol supplementation improves muscle macro- and microvascular but not anabolic responses to amino acids in older men. Appl Physiol Nutr Metab. 2016;41(5):548-56.

5.         Din USU, Sian TS, Deane CS, Smith K, Gates A, Lund JN, et al. Green Tea Extract Concurrent with an Oral Nutritional Supplement Acutely Enhances Muscle Microvascular Blood Flow without Altering Leg Glucose Uptake in Healthy Older Adults. Nutrients. 2021;13(11).

6.         Deane CS, Din USU, Sian TS, Smith K, Gates A, Lund JN, et al. Curcumin Enhances Fed-State Muscle Microvascular Perfusion but Not Leg Glucose Uptake in Older Adults. Nutrients. 2022;14(6).

7.         Nyberg M, Christensen PM, Blackwell JR, Hostrup M, Jones AM, Bangsbo J. Nitrate-rich beetroot juice ingestion reduces skeletal muscle O(2) uptake and blood flow during exercise in sedentary men. J Physiol. 2021;599(23):5203-14.

REFERENCES

8.         Timmerman KL, Lee JL, Dreyer HC, Dhanani S, Glynn EL, Fry CS, et al. Insulin stimulates human skeletal muscle protein synthesis via an indirect mechanism involving endothelial-dependent vasodilation and mammalian target of rapamycin complex 1 signaling. J Clin Endocrinol Metab. 2010;95(8):3848-57.

9.         Sheffield-Moore M, Wiktorowicz JE, Soman KV, Danesi CP, Kinsky MP, Dillon EL, et al. Sildenafil increases muscle protein synthesis and reduces muscle fatigue. Clin Transl Sci. 2013;6(6):463-8.

10.       Holloway TM, Snijders T, J VANK, LJC VANL, Verdijk LB. Temporal Response of Angiogenesis and Hypertrophy to Resistance Training in Young Men. Med Sci Sports Exerc. 2018;50(1):36-45.

11.       Verdijk LB, Snijders T, Holloway TM, J VANK, LJ VANL. Resistance Training Increases Skeletal Muscle Capillarization in Healthy Older Men. Med Sci Sports Exerc. 2016;48(11):2157-64.

REFERENCES

12.       Lixandrão ME, Damas F, Chacon-Mikahil MP, Cavaglieri CR, Ugrinowitsch C, Bottaro M, et al. Time Course of Resistance Training-Induced Muscle Hypertrophy in the Elderly. J Strength Cond Res. 2016;30(1):159-63.

13.       Snijders T, Nederveen JP, Joanisse S, Leenders M, Verdijk LB, van Loon LJ, et al. Muscle fibre capillarization is a critical factor in muscle fibre hypertrophy during resistance exercise training in older men. J Cachexia Sarcopenia Muscle. 2017;8(2):267-76.

14.       Nederveen JP, Joanisse S, Snijders T, Thomas ACQ, Kumbhare D, Parise G. The influence of capillarization on satellite cell pool expansion and activation following exercise-induced muscle damage in healthy young men. J Physiol. 2018;596(6):1063-78.

15.       Betz MW, Aussieker T, Kruger CQ, Gorissen SHM, van Loon LJC, Snijders T. Muscle fiber capillarization is associated with various indices of skeletal muscle mass in healthy, older men. Exp Gerontol. 2021;143:111161.

16.       Kohn TA, Essén-Gustavsson B, Myburgh KH. Specific muscle adaptations in type II fibers after high-intensity interval training of well-trained runners. Scand J Med Sci Sports. 2011;21(6):765-72.

17.       Gliemann L, Gunnarsson TP, Hellsten Y, Bangsbo J. 10-20-30 training increases performance and lowers blood pressure and VEGF in runners. Scand J Med Sci Sports. 2015;25(5):e479-89.

REFERENCES

18.       Hoier B, Passos M, Bangsbo J, Hellsten Y. Intense intermittent exercise provides weak stimulus for vascular endothelial growth factor secretion and capillary growth in skeletal muscle. Experimental Physiology. 2013;98(2):585-97.

19.       Rivilis I, Milkiewicz M, Boyd P, Goldstein J, Brown MD, Egginton S, et al. Differential involvement of MMP-2 and VEGF during muscle stretch- versus shear stress-induced angiogenesis. Am J Physiol Heart Circ Physiol. 2002;283(4):H1430-8.

REFERENCES

20.       Hudlicka O, Milkiewicz M, Cotter MA, Brown MD. Hypoxia and expression of VEGF-A protein in relation to capillary growth in electrically stimulated rat and rabbit skeletal muscles. Exp Physiol. 2002;87(3):373-81.

21.       Lundberg TR, Fernandez-Gonzalo R, Gustafsson T, Tesch PA. Aerobic exercise does not compromise muscle hypertrophy response to short-term resistance training. Journal of Applied Physiology. 2013;114(1):81-9.

22.       Mikkola J, Rusko H, Izquierdo M, Gorostiaga EM, Häkkinen K. Neuromuscular and cardiovascular adaptations during concurrent strength and endurance training in untrained men. Int J Sports Med. 2012;33(9):702-10.

23.       Murach KA, Bagley JR. Skeletal Muscle Hypertrophy with Concurrent Exercise Training: Contrary Evidence for an Interference Effect. Sports Med. 2016;46(8):1029-39.

REFERENCES

24.       Holloway TM, Morton RW, Oikawa SY, McKellar S, Baker SK, Phillips SM. Microvascular adaptations to resistance training are independent of load in resistance-trained young men. Am J Physiol Regul Integr Comp Physiol. 2018;315(2):R267-r73.

25. Thomas ACQ, Brown A, Hatt AA, Manta K, Costa-Parke A, Kamal M, et al. Short-term aerobic conditioning prior to resistance training augments muscle hypertrophy and satellite cell content in healthy young men and women. Faseb j. 2022;36(9):e22500.

About The Author