Akt	Protein kinase B; serine/threonine kinase central to insulin signaling and glucose uptake
AMPK	AMP-activated protein kinase; key energy sensor promoting glucose uptake and fatty-acid oxidation
AS160	Akt substrate of 160 kDa (also known as TBC1D4); regulates GLUT4 vesicle trafficking
ATP	Adenosine triphosphate; cellular energy currency
BGP-15	Hydroximic acid derivative and pharmacologic HSP co-inducer that improves insulin sensitivity
CaMKII	Calcium/calmodulin-dependent protein kinase II; mediates calcium signaling during muscle contraction
CK	Creatine kinase; marker of muscle damage
DAMPs	Damage-associated molecular patterns; endogenous molecules triggering immune activation
eHSP70	Extracellular heat shock protein 70; circulating form with immunomodulatory function
ER	Endoplasmic reticulum; site of protein folding and the unfolded-protein response (UPR)
FFA	Free fatty acid; lipid species contributing to insulin resistance when elevated
FOXO	Forkhead box O transcription factors; mediate muscle atrophy and oxidative stress responses
GLUT4	Glucose transporter type 4; insulin-responsive transporter in skeletal muscle and adipose tissue
HFD	High-fat diet; experimental model for inducing metabolic dysfunction
HSP	Heat shock protein; conserved molecular chaperone family aiding in protein folding and stress tolerance
HSP70 (Hsp70)	Inducible 70-kDa heat shock protein; central focus of this review
Hsc70	Heat shock cognate 70; constitutively expressed member of the HSP70 family
HSP72	Common designation for inducible HSP70 isoform in human studies
HSP90	90-kDa heat shock protein; stabilizes signaling proteins including kinases and steroid receptors
HSF1	Heat shock factor 1; transcriptional regulator of heat shock proteins
iHSP70	Inducible/intracellular heat shock protein 70; stress-responsive isoform
IGF-1	Insulin-like growth factor 1; anabolic growth factor activating PI3K/Akt/mTOR signaling
IL-6	Interleukin-6; cytokine modulating inflammation and metabolic signaling
iNOS	Inducible nitric oxide synthase; produces nitric oxide during inflammatory stress
IRS-1	Insulin receptor substrate-1; adaptor protein mediating insulin receptor signaling
JNK	c-Jun N-terminal kinase; stress-activated kinase impairing insulin signaling when overactive
LKB1	Liver kinase B1; upstream activator of AMPK
MAPK	Mitogen-activated protein kinase; family of kinases including ERK, JNK, and p38
mTOR	Mechanistic target of rapamycin; key regulator of growth and metabolism
mTORC1	mTOR complex 1; regulates protein synthesis and cell growth
mTORC2	mTOR complex 2; activates Akt by Ser473 phosphorylation
NF-κB	Nuclear factor-κB; transcription factor controlling inflammatory gene expression
nNOS	Neuronal nitric oxide synthase; enzyme generating NO in skeletal muscle
NO	Nitric oxide; vasodilator regulating blood flow and glucose delivery
Nox2	NADPH oxidase 2; enzyme complex generating reactive oxygen species (ROS)
PGC-1α	Peroxisome proliferator-activated receptor gamma coactivator-1 alpha; master regulator of mitochondrial biogenesis
PI3K	Phosphoinositide 3-kinase; mediates insulin signaling downstream of IRS-1
PKB	Protein kinase B (synonymous with Akt)
PPARα	Peroxisome proliferator-activated receptor alpha; nuclear receptor promoting fatty-acid oxidation
RNS	Reactive nitrogen species; nitrogen-derived oxidants affecting signaling and stress responses
ROS	Reactive oxygen species; oxygen-derived oxidants contributing to oxidative stress
SERCA	Sarco/endoplasmic reticulum Ca2+-ATPase; pumps calcium into SR for muscle relaxation
SIRT1	Sirtuin 1; NAD+-dependent deacetylase regulating mitochondrial function and metabolism
SR	Sarcoplasmic reticulum; intracellular Ca2+ storage organelle in muscle
T2D	Type 2 diabetes mellitus
TBC1D1	Tre-2/Bub2/Cdc16-domain family member 1; Rab GTPase-activating protein modulating GLUT4 vesicle traffic
TBC1D4	Tre-2/Bub2/Cdc16-domain family member 4 (also AS160); regulates GLUT4 translocation
TNF-α	Tumor necrosis factor-alpha; pro-inflammatory cytokine implicated in insulin resistance
UPR	Unfolded protein response; ER-stress pathway maintaining proteostasis
VO2max	Maximal oxygen consumption; measure of aerobic capacity